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Important! Big problem with my 92 Corvette, does not start! Security lights blinking! HELP!! SOS

John Robinson

Gone but not forgotten
Joined
May 3, 2005
Messages
1,555
Location
Muncie, Indiana
Corvette
1993 Polo Green Coupe
I believe you put an MSD unit in place of the opti. On the opti there was a wire connector on top of it. What did you do with that wire connector. Did it reconnect to the MSD unit. The reason I ask is what I saw on your video looked an awful lot like how my car ran with that connector not making good connection. On the opti with that connector being right under the heater hose connection when it blew up it watered down the connector and the car would backfire and sputter and run if I feathered the throttle but mostly it just would stop. Also that connectors ground wire goes to the same ground bundle as the TPS. If you look at the information on open and closed loop you will see that the ecm ignores that circuit in closed loop. When you start the car the ecm wants to be in open loop and that is when it wants input from the TPS, Water Temp, and the MAP since they all go to a common ground bundle I would look there first to see if you have a bad ground bundle. When the engine gets to a predetermined temperature the ecm goes to closed loop and no longer needs the TPS, Water Temp or MAP input since it switches to the O2 sensor to maintain fuel and spark. I am not an electric engineer but it seems to me that if the car runs without the memcal in it is being forced to run in closed loop. I base that on the fact that the memcal is programmable read only memory and so I think that is the unit that governs which loop the car is in. By now all of the connectors and wires have been handled several times and the results with this old wiring could be that some are broken. Which could be the cause of you trouble.
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
I believe you put an MSD unit in place of the opti. On the opti there was a wire connector on top of it. What did you do with that wire connector. Did it reconnect to the MSD unit. The reason I ask is what I saw on your video looked an awful lot like how my car ran with that connector not making good connection. On the opti with that connector being right under the heater hose connection when it blew up it watered down the connector and the car would backfire and sputter and run if I feathered the throttle but mostly it just would stop. Also that connectors ground wire goes to the same ground bundle as the TPS. If you look at the information on open and closed loop you will see that the ecm ignores that circuit in closed loop. When you start the car the ecm wants to be in open loop and that is when it wants input from the TPS, Water Temp, and the MAP since they all go to a common ground bundle I would look there first to see if you have a bad ground bundle. When the engine gets to a predetermined temperature the ecm goes to closed loop and no longer needs the TPS, Water Temp or MAP input since it switches to the O2 sensor to maintain fuel and spark. I am not an electric engineer but it seems to me that if the car runs without the memcal in it is being forced to run in closed loop. I base that on the fact that the memcal is programmable read only memory and so I think that is the unit that governs which loop the car is in. By now all of the connectors and wires have been handled several times and the results with this old wiring could be that some are broken. Which could be the cause of you trouble.

:O Wowwwww John! You really KNOW about corvettes man!

Im really impressed with that car, is fascinating... if you bridge the scanner connector, you can know if everything works fine, even a bulb! That car is really amazing... really amazing... and is maded by the normal people can do that kind of stuff....No Mercedes i had has that amazing things, so im really impressed with that car....

That car is really complicated like i know about several months ago, but now, i think is more complicated that i thought, thats AMAZING that loops that you are explaining me... im really impressed...

I really think that is the problem of my car, and now, in what wires i need to search to discover my problem? because i really want to fix my car :-( my new wiring i think it arrives in like 1 month, and i would be happy if i repair my car soon. And with your help, i think i can :)

Now, thats the MSD distributor Story:

When i bought the MSD distributor in USA, it arrived to my country in 3 days because i want it now and i payed 100$ only for the shipment DHL via. The total cost was 780$, complete distributor.

Well... when my beautiful distributor arrives to my home, i inmediately disarm my car, the water pump, and everything, and i put there my new distributor like in the distributor manual says, and everything is perfect, when i connect the MSD connector and the connector on the harness of my car, i see that CANT fit... connector of the wiring has 5 wires and the MSD only 4 and the connectors was tottally diferent... i sent an email to the seller and to a MSD, very upset because in the box says ``92 to 94 LT1 corvettes´´, well they send me that email:

David,
>
> You really need to solder the wires, if you butt connect them, you chance it
> getting loose. Once you cut the wire on the MSD, MSD will not warranty the
> distributor.
>
> All the wires are the same, pin to pin. The PIN locations are very small
> and are cast into the plastic connector. They are the same on the 4-pin
> connector as the 6-pin, so you should not be confused.
>
> Pin 1 on the MSD (brown/yellow wire) goes to Pin A (Blk/red wire) on harness
> Pin 2 on the MSD (brown/orange wire) goes to Pin B (purple/white wire) on
> harness
> Pin 3 on the MSD (red wire) goes to Pin C (yellow wire) on the harness
> Pin 4 on the MSD (red/black wire) goes to Pin D (black/pink wire) on the
> harness
>
> A PDF file is also e-mailed for reference.

I do exactly the same thing, i solder the wires, a perfect job. That is because ONLY THE 92 CORVETTE has a different connector on the DISTRIBUTOR, only the 92, look at that :) in 93 the connector changed and if my car was 93 i do not will need to solder any wire.... only plug and play....

The MSD distributor has another vaacum lines, that i connected really well, i think was a good job. But, i think discovering the failure that i or the mechanic do something wrong and now the car has that failure, i will like to know why, and what, to fix it :)

Another thing: Without the memcal, the fans are ALL THE TIME activated, i pass the suich and they work, and works all the time, the 2 fans... so my car is really cool all the time. Sometimes the car throws a smell that my eyes dont like it.... my mechanic told me is ``raw gasoline´´ and only for 1 exhaust, the passengers side one.

Really thanks for everything John, now im waiting to know what i need to do or what wires check to start fixing my car! :) Read this to know what i did and what i need to do, for the distributor... or my failure.

Another stuff of my car, sometimes the car sounds in the exhaust hard, like an explosion, like if the spark was too much or the gasoline blow up a little bit because the car is not good entonated, and that happens when i accelerate it several times at once.

Another question, if my MSD is not working good because i need another wire or 1 wire is broken, why the car starts? i think that will not work at all and the car will not have spark because the distributor is not working good, or the distributor can works parcially? Well im not a mechanic and i dont know anything about that, i did several jobs on my cars and i like flawless jobs, averything in his place, cleaned and good threated, and if i dont know how to disarm something, i think and i do my best to dont wreck anything... My mechanics dont, it disarms everything fast and sometimes broke a plastic and that things.. well, thats one of the reasons that i like to fix my car :)

Im here to listen you :) the people who knows!
 

John Robinson

Gone but not forgotten
Joined
May 3, 2005
Messages
1,555
Location
Muncie, Indiana
Corvette
1993 Polo Green Coupe
Follow this chart to verify the wiring is good.

File1.jpgFile.jpgFile4.jpg
Also the chart for the ecm and connector shows were the pin for the blk/pink is. If you take the connector off the ecm you can do a continuity check of that wire from the plug on the distributor. That is the ground wire. When doing the continuity check wiggle the wires to see if you lose continuity.
 

K & B Special Products

Active member
Joined
Jul 13, 2011
Messages
39
Location
Alpharetta, GA
Corvette
1967 red/red 2010 red
:O Wowwwww John! You really KNOW about corvettes man!

Im really impressed with that car, is fascinating... if you bridge the scanner connector, you can know if everything works fine, even a bulb! That car is really amazing... really amazing... and is maded by the normal people can do that kind of stuff....No Mercedes i had has that amazing things, so im really impressed with that car....

That car is really complicated like i know about several months ago, but now, i think is more complicated that i thought, thats AMAZING that loops that you are explaining me... im really impressed...

I really think that is the problem of my car, and now, in what wires i need to search to discover my problem? because i really want to fix my car :-( my new wiring i think it arrives in like 1 month, and i would be happy if i repair my car soon. And with your help, i think i can :)

Now, thats the MSD distributor Story:

When i bought the MSD distributor in USA, it arrived to my country in 3 days because i want it now and i payed 100$ only for the shipment DHL via. The total cost was 780$, complete distributor.

Well... when my beautiful distributor arrives to my home, i inmediately disarm my car, the water pump, and everything, and i put there my new distributor like in the distributor manual says, and everything is perfect, when i connect the MSD connector and the connector on the harness of my car, i see that CANT fit... connector of the wiring has 5 wires and the MSD only 4 and the connectors was tottally diferent... i sent an email to the seller and to a MSD, very upset because in the box says ``92 to 94 LT1 corvettes´´, well they send me that email:

David,
>
> You really need to solder the wires, if you butt connect them, you chance it
> getting loose. Once you cut the wire on the MSD, MSD will not warranty the
> distributor.
>
> All the wires are the same, pin to pin. The PIN locations are very small
> and are cast into the plastic connector. They are the same on the 4-pin
> connector as the 6-pin, so you should not be confused.
>
> Pin 1 on the MSD (brown/yellow wire) goes to Pin A (Blk/red wire) on harness
> Pin 2 on the MSD (brown/orange wire) goes to Pin B (purple/white wire) on
> harness
> Pin 3 on the MSD (red wire) goes to Pin C (yellow wire) on the harness
> Pin 4 on the MSD (red/black wire) goes to Pin D (black/pink wire) on the
> harness
>
> A PDF file is also e-mailed for reference.

I do exactly the same thing, i solder the wires, a perfect job. That is because ONLY THE 92 CORVETTE has a different connector on the DISTRIBUTOR, only the 92, look at that :) in 93 the connector changed and if my car was 93 i do not will need to solder any wire.... only plug and play....

The MSD distributor has another vaacum lines, that i connected really well, i think was a good job. But, i think discovering the failure that i or the mechanic do something wrong and now the car has that failure, i will like to know why, and what, to fix it :)

Another thing: Without the memcal, the fans are ALL THE TIME activated, i pass the suich and they work, and works all the time, the 2 fans... so my car is really cool all the time. Sometimes the car throws a smell that my eyes dont like it.... my mechanic told me is ``raw gasoline´´ and only for 1 exhaust, the passengers side one.

Really thanks for everything John, now im waiting to know what i need to do or what wires check to start fixing my car! :) Read this to know what i did and what i need to do, for the distributor... or my failure.

Another stuff of my car, sometimes the car sounds in the exhaust hard, like an explosion, like if the spark was too much or the gasoline blow up a little bit because the car is not good entonated, and that happens when i accelerate it several times at once.

Another question, if my MSD is not working good because i need another wire or 1 wire is broken, why the car starts? i think that will not work at all and the car will not have spark because the distributor is not working good, or the distributor can works parcially? Well im not a mechanic and i dont know anything about that, i did several jobs on my cars and i like flawless jobs, averything in his place, cleaned and good threated, and if i dont know how to disarm something, i think and i do my best to dont wreck anything... My mechanics dont, it disarms everything fast and sometimes broke a plastic and that things.. well, thats one of the reasons that i like to fix my car :)

Im here to listen you :) the people who knows!

You got robbed! MSD=may suddenly die. Stock, CORRECT Delphi distributor $400!
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
You got robbed! MSD=may suddenly die. Stock, CORRECT Delphi distributor $400!

ahaha, i bought MSD because my delphi died because i wash the engine of my car when i wash the car and the distributor had corrosion inside and stop working, for that reason i bought MSD and i have washed my car like 50 times since i put this on it and perfect! And the car has more spark now, i love the MSD one... and has better warranty than delphi, for that reason i bought it!

Now, you scared me my friend ahahahha i hope my MSD least 3 years or more.... i hope so! I dont want less.... ahaha

And another good stuff, with the MSD you can graduate the spark of the car, has a graduator, i dont know what it works but sounds grate... when my car runs perfect i will graduate it for the best way to have more HP with my mechanic :)
 

John Robinson

Gone but not forgotten
Joined
May 3, 2005
Messages
1,555
Location
Muncie, Indiana
Corvette
1993 Polo Green Coupe
And another good stuff, with the MSD you can graduate the spark of the car, has a graduator, i dont know what it works but sounds grate... when my car runs perfect i will graduate it for the best way to have more HP with my mechanic :)

For heavens sake don't mess with it if you get it to run leave it alone. By now you should have guessed that GM knew what to do to get the car to be dependable for daily driving. Part of your problem is you have not taken the car back to what it was designed with. Until you have driven the car running like it was designed to run don't even think about trying to improve on the original design. You may find that the car has all the performance you need without screwing it up again with after market and pie in the sky performance upgrades. After looking at the video of you burning rubber that showed the tires cord showing through spend your money on tires instead.
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
For heavens sake don't mess with it if you get it to run leave it alone. By now you should have guessed that GM knew what to do to get the car to be dependable for daily driving. Part of your problem is you have not taken the car back to what it was designed with. Until you have driven the car running like it was designed to run don't even think about trying to improve on the original design. You may find that the car has all the performance you need without screwing it up again with after market and pie in the sky performance upgrades. After looking at the video of you burning rubber that showed the tires cord showing through spend your money on tires instead.

Yes my friend! i love to race! And that video was before putting 4 new bridgestone potenza tires :) annnnd, in that video, is my car with the failure, I CANT PASS 3.000RPM!!! And in the video the max RPM i got it was 3.000, so, look at what my car can do with 3.000rpm only, and think now what my car can do with his maximum 6.000rpm! :)

Okay, tomorrow a friend of mine expert in that stuff will come to check what you gave me if see if we can fix it :)

Annnd, i will order a DELPHI distributor to put it in his place when i got my new wiring harness (if the failure continues when i install my new harness), to see if thats the problem, the MSD distributor.

Well my friends the only upgrades of my car are:

-MSD complete distributor
-MSD coil (the connectors are the same than the original coil so i think here we got no problem)
-Spec stage 3 clutch
-Granatelli Motorsports Walbro 255lph fuel pump
-K&N air filter
-Catalytics converters removed!

And nothing more i remember now... im for upgrading my car better, with a 58mm throttle body, msd spark plug wires, 35lb inyectors, 2bar MAP sensor, crane cam and roller rockers, and many upgrades more, my goal is put my car in 425hp or something.

Well, the only upgrade that i need to cut wires was with the distributor, the other upgrades were like ORIGINAL TO FIT IN MY CAR WITH NO MODS, only plug and play.

But the other upgrades must to wait, because i need to fix my problem now before it.

I want more HP in my corvette because a friend of mine has a dodge viper, and i want to beat it, and when i beat it maybe i buy the viper to put some upgrades in that car too :)

Im looking that information to understand it well, im reading all of it, i hope tomorrow i can fix my problem without new wires! New wires are comming! But... if i fix it sooner, better. :beer
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
Yes my friend! i love to race! And that video was before putting 4 new bridgestone potenza tires :) annnnd, in that video, is my car with the failure, I CANT PASS 3.000RPM!!! And in the video the max RPM i got it was 3.000, so, look at what my car can do with 3.000rpm only, and think now what my car can do with his maximum 6.000rpm! :)

Okay, tomorrow a friend of mine expert in that stuff will come to check what you gave me if see if we can fix it :)

Annnd, i will order a DELPHI distributor to put it in his place when i got my new wiring harness (if the failure continues when i install my new harness), to see if thats the problem, the MSD distributor.

Well my friends the only upgrades of my car are:

-MSD complete distributor
-MSD coil (the connectors are the same than the original coil so i think here we got no problem)
-Spec stage 3 clutch
-Granatelli Motorsports Walbro 255lph fuel pump
-K&N air filter
-Catalytics converters removed!

And nothing more i remember now... im for upgrading my car better, with a 58mm throttle body, msd spark plug wires, 35lb inyectors, 2bar MAP sensor, crane cam and roller rockers, and many upgrades more, my goal is put my car in 425hp or something.

Well, the only upgrade that i need to cut wires was with the distributor, the other upgrades were like ORIGINAL TO FIT IN MY CAR WITH NO MODS, only plug and play.

But the other upgrades must to wait, because i need to fix my problem now before it.

I want more HP in my corvette because a friend of mine has a dodge viper, and i want to beat it, and when i beat it maybe i buy the viper to put some upgrades in that car too :)

Im looking that information to understand it well, im reading all of it, i hope tomorrow i can fix my problem without new wires! New wires are comming! But... if i fix it sooner, better. :beer

My friends i need your help! I dont know how it works the sales in your country (USA) but i dont understand nothing... i really dont have problems with my MSD things, headers, etc....

but, trying to buy my ENGINE WIRING HARNESS is really complicated... because i CANT FIND IT IN NO WEBSITE..... emails and emails... calls and calls... and nothing!

I can find only are engine SWAP harness, to put a 92 corvette engine into and old car.... and, if i buy one of this, how i can make work good all my cluster gauges? i really want the original one....

please i need help i cant find it in nowhere :-( i have the money but i dont have the article, so....
 

John Robinson

Gone but not forgotten
Joined
May 3, 2005
Messages
1,555
Location
Muncie, Indiana
Corvette
1993 Polo Green Coupe
Before you go any further with the wiring you might try this. There has been a lot of talk on other forums lately about the msd coils not being very good. If you have the original coil try putting it back on the car and see how it runs. For some reason they are breaking down and causing all kinds of problems with missing poor performance etc.
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
Before you go any further with the wiring you might try this. There has been a lot of talk on other forums lately about the msd coils not being very good. If you have the original coil try putting it back on the car and see how it runs. For some reason they are breaking down and causing all kinds of problems with missing poor performance etc.

I tried that my friend :) testing, i replaced my MSD distributor and my MSD coil, put it the original ones, same problem....

my car now is stock in everything excepting the fuel pump, has a walbro 255lph one, but thats not the problem... the problem is electrical.

if you see the wiring of my car you will depress, is in really bad condition, i need to replace it and i wonder thats the problem....

My car now is almost new! 4 new bridgestone potenza tires 275/40 r17, new paint, carbon fiber interior (the plastic panels), DVD touch screen stereo, etc... Lovely... but i cant pass 3.000rpm :-( without memcal the car is boring, fast as hell but not that fast...

Now the car has msd distributor, msd coil, and perfect! but i have 2 new coils (original ones) i can test if you can but thats not the problem, i can swear that :) i tested that 3 weeks ago and the same :) now im an expert replacing corvettes distributors.

Another stuff, my car has an oil leak, i need to change the[FONT=arial, sans-serif] [/FONT]crankcase gasket, and i see i need to put my engine out, thats true or exist a little trick?

now i need is my wiring or another help to solve my problem and love my vette again :)
 

John Robinson

Gone but not forgotten
Joined
May 3, 2005
Messages
1,555
Location
Muncie, Indiana
Corvette
1993 Polo Green Coupe
Another stuff, my car has an oil leak, i need to change thecrankcasegasket, and i see i need to put my engine out, thats true or exist a little trick?

Are you sure it is the crankcase that is leaking. The reason I ask is I thought I had a leak from the seal on the crank on my 93. When I got to looking at it very carefully I discovered that the intake manifold was leaking and the oil was running down behind the water pump making me think it was the seal that was bad. I replace the gasket and it was fine for a couple of months and then I had oil from the rear seal area. Again when I looked carefully I found that I had not gotten a good seal on the back of the manifold and it was leaking down over the bell housing and dripping like a rear seal leak.

If you find that to be the problem be sure that when you put the rtv on the front and back of the block that you let it set for at least 2 hours to cure. Then set the manifold down on it and just use the bolts to locate the manifold on the block do not tighten them. After a minimum of 2 hours preferably over night of setting then torque the manifold in place. If you rush this job you will end up with a leak again the rtv has to be partially cured so it can adhear to the two surfaces and not be squeezed out.
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
Thanks my friends! Now i will check all that information!

Now i will gift you a few pics of my vette with barbie girls and me :D

382100_10150929648135417_673490416_22850203_1889754732_n.jpg296302_10150929797420417_673490416_22851718_1961725964_n.jpg376549_10150929805275417_673490416_22851786_482057511_n.jpg387552_10150929806555417_673490416_22851799_44231969_n.jpg390176_10150929850900417_673490416_22852336_51407357_n.jpg297693_10150929580340417_673490416_22849718_966477151_n.jpg

Thaths a way to thank your help, enjoy ;-)

I will read everything you send me and i post again later :p :beer
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
Thanks my friends! Now i will check all that information!

Now i will gift you a few pics of my vette with barbie girls and me :D

View attachment 6203View attachment 6204View attachment 6205View attachment 6206View attachment 6207View attachment 6208

Thaths a way to thank your help, enjoy ;-)

I will read everything you send me and i post again later :p :beer

Hello everybody!

My friends! In that weeks i didint have time to fix my car, so i used it at 3.000rpm every day and perfect!

Now im in University VACATIONS and i have a lot of time! Yesterday i readed all the comments that you send me and i did everything you said.

Today i have removed the wiring of my car, i checked 1 by 1, tps, iac, distributor, etc, etc, etc... all the wires are good, have continuity to the ecm, there´s 2 wires broken from the tps and i repared it.

I put the harness in my car and i turns on, same problem, nothing happened, but i feel the car better than before. I remove the memcal, car runs perfect but you cant pass 3.000rpm, you dont know what speed are you going, fans are always on, etc, etc, etc... I put the memcal, car turns on but inmediately turns off.


Now, i discovered an interesting thing:


I drove my car to a rise, withouth memcal, to 3000rpm, okay, when i was in the top, i put the memcal in my car, and i try to start, starts but inmediately turns off, okay, i drive the car down, off, i put first gear and i loose the clutch! Car starts and i accelerate it inmediately! Car stays PERFECT! to the maximum rpm, i drove that for 20 minutes, i was happy, incredible.... but, when i got traffic, the car turns off, only way to start is removing the memcal because i dont have a climb to start it down with the speeds.


Now, conclution, the car if you start it like i started, you can drive PERFECTLY! everything works perfectly and everything is amazing! But if you decrease less than 1.500rpm the car turns off, so, is something wrong that dont stays the car on... because it cant mantain the minimum of the engine.


Any ideas?


I scan the car and says C12, that means everythings good! how can it be everything okay if my car turns off????

Now we are sooo much closer to the failure!



I hope you can help me!


Thanks a lot to everybody!
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
Check your IAC plug to be sure it is in firmly

Thanks John! iac connector is perfect! Now.....

Now im in vacations, so i have a lot of time free... and i want to spend it in my corvette!

Last week i removed ALL THE ENGINE WIRING HARNESS.... I have been checked one by one all the wires.... with my tester... all wires have continuity... i found only 1 broken wire from the TPS, i repaired it....

Now, my ECM connectors have missed the plastic thing who retains the wires into the connector, so i dont know if the old owner changed a wire in one of the connectors, so if exist a guide to know what wire goes in the connectors will be grate, the colors... to see if one wire of the ECM connector is changed!

423752_10151342900625417_673490416_24373926_512416984_n.jpg

here you can see the gray connector and the green connector does not have the retainer....for that reason i think maybe theres a changed wire there...
421272_10151342902490417_673490416_24373940_1195476680_n.jpg

This is what it looks my engine without a wire... a lot of job to remove it and install it again....

428336_10151320760940417_673490416_24298269_1488741043_n.jpg

What a lot of quantity of wires to a car... only in the engine... oh my god!

Now i know that the engine wiring is not the problem, ECM is not the problem i have been checked again with my friend´s 93 vette, with my memcal, and perfect... turns on his car and runs perfect, i put his ECM in my vette with my memcal, same problem... so, ecm is new, and its not the problem.... now?

Engine wiring perfect, ecm and memcal perfect, it least a sensor like TPS, MAP, damaged or CCM damaged (i dont think so) or interior wiring dash harness (comming to the engine to the ccm) with a broken wire. Thats my conclution but im not a mechanic or anything so i dont know....

TPS is new, i bought a 115tps new from my dealership, it told me the 92 corvette uses the 115tps and i replace it. I bought a map sensor that looks indentical to my map sensor, and i put it and the car has the same failure... a NEW MSD distributor was put in the car about a year ago searching the ``dont start failure´´ that i have in the past... i want to put the old distributor to test if its the distributor the problem of my car....

Failure of the car? With the memcal in the ecm, car turns on but after 2 seconds turns off, if you accelerate it pumping, it remains on and accelerate it to the rpm you want..... it seems that its something wrong in the car that sends an intermitent impulse to an electronic part that remains the car ON withouth accelerate it pumping... in other words... an electronic thing that do the job that i do accelerate it pumping....

Now, if you start the car with an speed in a downhill with the memcal in the ECM, at 20km per hour or more, the car starts perfect, EVERYTHING WORKS PERFECT, you can pass 5.500rpm and the car just flyes!!! A beast machine!! But, if you get 1.500rpm or less, the car will turn off.

If you remove the memcal from the ECM the car stays ON PERFECT and you can drive it perfect the miles you want... but:

-You cant pass engine from 3.000rpm, 3.000rpm is the maximum rpm you can reach!
-When the car is cold, its like an old car with a carburator failure... When its hot, perfect!
-In the Dash says ''0''km al the time, you cant know at what speed are you going....

So, my mind will blow off with my car.. i really love it and i have spent a lot of money in it....and no results...

i hope if someone can help me, because i think im closer to find the failure and now i have a lot of time, so PLEASE help me guys :-( :ugh:eyerole;worship:thanks:
 

John Robinson

Gone but not forgotten
Joined
May 3, 2005
Messages
1,555
Location
Muncie, Indiana
Corvette
1993 Polo Green Coupe
Do you have the IAC hooked up?


Have you removed the IAC?


The IAC is very sensitive and damages easily when not properley handled.


The IAC controls the idle
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
Do you have the IAC hooked up?


Have you removed the IAC?


The IAC is very sensitive and damages easily when not properley handled.


The IAC controls the idle

i will remove the IAC to know if its that :) the IAC connector was broken in the past, so i dont know if the wires are in his correct place, if anyone has a pic of the IAC connector in a 92 corvette i will apreciate that, and, if its damaged, how it works with the car when you start it with an speed in a downhill?

maybe its the IAC now im going to remove it and clean it to see :)

I need the plans or a pictures of one of you guys the ecm connectors in a 92 corvette manual transmission electronic air conditioning, and pic of the IAC connector to see if the colors of the wires are in this place to be discarded things :D :happyanim:

Well... i just cant remove the IAC valve, so big, i dont have a tool to remove that... tomorrow i will call my mechanic to remove that.

Okay, now, i think a video explain more than 1.000 words, so i recorded 2 videos now to explain better my failure.

There are the vids :D

Problems with my 92 corvette, any ideas whats wrong? - YouTube

and the part 2

Problems with my vette, a little bit failure....part 2 - YouTube

Any ideas? the IAC valve is the same in the blazer and that chevy cars? to buy it tomorrow new!!!
 

Bestdavidd

Well-known member
Joined
Mar 14, 2011
Messages
69
Location
South America
Corvette
1992 Chevrolet Corvette LT1 Engine manual trans
Do you have the IAC hooked up?


Have you removed the IAC?


The IAC is very sensitive and damages easily when not properley handled.


The IAC controls the idle

John, yesterday i removed the IAC valve... tested anddd, when i turn the switch off, the iac valve shoots the thing inside.... it goes flying... i armed again the iac and installed it, and now the car is always on 1.500rpm without memcal.... too much!

reading and reading look that i found Signs and Symptoms of a Bad Idle Air Control Sensor | eHow.com

start and stall is my failure. The IAC is very expensive, in USA cost more than 100$, in my country 400$.... if im going to replace it, i need to be sure :-(

butttttttttt, if its the IAC my failure, WHY THE CAR STARTS WITHOUT MEMCAL and remains perfect with the throttle?

My car will blow my mind and my mechanics mind! Anybody can take a picture of the ECM connectors in his 92 corvette to know if there its a wire changed? or in the book, to see the colors and see if theres a wire changed, because a mechanic here that he comes here to UNITED STATES 3 weeks ago, he told me yesterday this is the failure... changed wire in the ECM connectors, he checked the car and everything... he worked 17 years in ford repair workshop, but he told me he repair chevrolet too... including corvettes!!! so, i think he is right and thats easy to check.

Please guys help me here :-( because if anyone of you have that failure in the future, dont spend the money i have spent here (more than 5.000$) and repair his car with no problems.....

Thanks John;)
 

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