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

[Bestdavidd]

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

My friends, IAC new today, same problem :-(


old new


:ugh :cry

 

[John Robinson]

Did you ever buy the FSM? If so what you are lookin for is in section 6E3-A-11. At least that is were it is located in my 93 FSM. If you have not purchased an FSM your just going to be throwing more and more money at this car. If you have someone with a 92 Vette that is running well you might try swapping the ECM to your car and see what happens. Also you say you have an MSD distributor in place of the Opti. I have been reading other forums and it seems that the MSD unit is subject to failure and one of them is it will not allow the engine to run in the higher RPM range. If you have the old opti you might try to put it back on the car and see what happens with the memcal in place.

 

[Bestdavidd]

Did you ever buy the FSM? If so what you are lookin for is in section 6E3-A-11. At least that is were it is located in my 93 FSM. If you have not purchased an FSM your just going to be throwing more and more money at this car. If you have someone with a 92 Vette that is running well you might try swapping the ECM to your car and see what happens. Also you say you have an MSD distributor in place of the Opti. I have been reading other forums and it seems that the MSD unit is subject to failure and one of them is it will not allow the engine to run in the higher RPM range. If you have the old opti you might try to put it back on the car and see what happens with the memcal in place.

what is FSM?

I have a Friend with a 93 vette, manual, and we put my ecm with my memcal in his car, his car perfect.... we put his ecm with my memcal in my car, same problem, so, ecm is not the problem, and the ecm and my memcal is new, so...

i will change the distributor again, to see what happens, putting the old one there and see if its my problem that i dont think so.

Im still believing in the mechanic from USA who told me is a wire changed in ecm connectors :-( if anyone can take pictures to his ecm connectors in a 92 corvette i can see if theres a changed wire, because in my friends 93 all wires are diferent colors :cry

 

[boomdriver]

FSM = Factory Service Manual

MSD = Mucho Shiddy Distributer

 

[Bestdavidd]

FSM = Factory Service Manual

MSD = Mucho Shiddy Distributer

aaahahahaha i think you are right! but the MSD gives the LT1 more ponyes!! that is right!

look guys searching and searching and reading and reading... i found this!

i need something like that for a 92 corvette manual with automatic air conditioning to see if my ecm wires are good!!!!



i need you guys if anybody has a 92 corvette manual automatic air conditioning like mine, please take some pics like that to know if my wires are in order, well connected thats all i need to discard the engine wiring harness, the american mechanic guy told me this is the failure, wire changed in that ecm connectors because the gray and green one does not have the retainer and wires goes off easily! If i dont fix my failure and i sell something to get some money, i will do something drastically, i will buy new engine wiring harness, new dash harness completely and new ccm if i find it and all engine sensors and i think i will fix that problem! But i dont want to spend 2.000$ or more in that :-( because i dont have it right now! :cry

 

[John Robinson]

Ok if you have a friend with the 93 manual you have access to the FSM(Field Service Manual) Should be two volumes. One volume is the Driveability and emissions volume. In that manual you will go to the section 6E3-A-11 and the next 3 sheets are the charts showing the ecm pin connector and what wire goes to what pin for each of the 4 colored connectors. AT this time I am unable to scan the charts from my manual. I honestly think that if you have been doing all the things you say you have without a FSM you have created more problems than any of us could possible help you with. It seems as if we have a problem with understanding what is being asked and what is being suggested. I beleave it was almost a year ago when I suggested you check the wires to the TPS and you have just now gotten around to doing that and you found a bad wire. I wonder how much of what you have done in the last year was unnecessary if you had just checked that tps wiring. I wish you well with the car and do hope you can finally get it running right. But again you need to take some of that money you have thrown at the car and get a GM Field Service Manual. I know that it has saved me tons of money. When I have a problem I read it for several days and then I do the diagostic chart process and usually I find that it is something simple causing my problem. Mechanics who throw your money at the car without doing a complete diagnostic of the system involved are just parts changers. You need a mechanic who can understand the system and what it takes to get it right.

 

[Bestdavidd]

Ok if you have a friend with the 93 manual you have access to the FSM(Field Service Manual) Should be two volumes. One volume is the Driveability and emissions volume. In that manual you will go to the section 6E3-A-11 and the next 3 sheets are the charts showing the ecm pin connector and what wire goes to what pin for each of the 4 colored connectors. AT this time I am unable to scan the charts from my manual. I honestly think that if you have been doing all the things you say you have without a FSM you have created more problems than any of us could possible help you with. It seems as if we have a problem with understanding what is being asked and what is being suggested. I beleave it was almost a year ago when I suggested you check the wires to the TPS and you have just now gotten around to doing that and you found a bad wire. I wonder how much of what you have done in the last year was unnecessary if you had just checked that tps wiring. I wish you well with the car and do hope you can finally get it running right. But again you need to take some of that money you have thrown at the car and get a GM Field Service Manual. I know that it has saved me tons of money. When I have a problem I read it for several days and then I do the diagostic chart process and usually I find that it is something simple causing my problem. Mechanics who throw your money at the car without doing a complete diagnostic of the system involved are just parts changers. You need a mechanic who can understand the system and what it takes to get it right.

You are completely right John all the things i did, i did it with my mechanics... not alone... Very well done!

Things i did:
-replace the ecm, nothing easyest, just plug and play
-replace tps, easy
-Replace IAC, easy
-Replace distributor, medium
-replace memcal, easy
-Get out the engine wiring harness, check 1 by 1 wire and install it again, DAMN complicated!
-Change the spark plugs, easy but no much space, little tactic and now i replace all my spark plugs in 10 minutes....

The tps wire was not broken in the past, but manipulating the car the mechanics broke a wire in the tps connector, you can see it loose... just soldered to the connector and fix it!

Im just thinking to buy the wiring diagrams from here

Repair Diagrams for 1992 Chevrolet Corvette Engine, Transmission, Lighting, AC, Electrical & Warning Systems

what do you think about that page? only 4 dollars and you are able to see that!

I have a friend who has the book repair manual to the corvette, i think is you said to me, i just asked him tomorrow to see if he can sell me that!

 

[air1jpg]

Fsm

Fllow this link to see what FSM book set you need for your vette.
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

 

[John Robinson]

aaahahahaha i think you are right! but the MSD gives the LT1 more ponyes!! that is right!



look guys searching and searching and reading and reading... i found this!

i need something like that for a 92 corvette manual with automatic air conditioning to see if my ecm wires are good!!!!

View attachment 7911

i need you guys if anybody has a 92 corvette manual automatic air conditioning like mine, please take some pics like that to know if my wires are in order, well connected thats all i need to discard the engine wiring harness, the american mechanic guy told me this is the failure, wire changed in that ecm connectors because the gray and green one does not have the retainer and wires goes off easily! If i dont fix my failure and i sell something to get some money, i will do something drastically, i will buy new engine wiring harness, new dash harness completely and new ccm if i find it and all engine sensors and i think i will fix that problem! But i dont want to spend 2.000$ or more in that :-( because i dont have it right now! :cry

Not if it does not work. One thing is for sure. GM spent millions of dollars for research and engineering and testing to develope this system. My guess is that in doing so they found out that when you change one thing it effects others and so they set the parameters for the ignition so they would compliment each other. Think of a teeter toter that is balanced to keep each end even to the ground. Now add some weight to one end and what happens it goes down on that end. because it no longer is balanced. The same thing happens when you add after market parts. You upset the balance and will have to change other things to get it back. Oh and by the way just because a part is new does not mean it is a good part. Long story short I changed a coil on a car and it would not run over 50 MPH after hours of work I got mad and put the old coil back on and the car ran fine again. Up to then I had believed in the old saying a coil either works or it does'nt. Another point does your friends car run ok with your memcal in it? If it does then my guess is since the memcal is were the ecm stores it short term memory needs his car is giving it the correct data to function. If your car is not giving it the correct data then it will not program itself correctly. Back to the MSD unit if it is not producing the right voltage for higher rpm runninig then the memcal can not forward that to the ecm so it will provide full fuel and spark for higher rpm. Please understand what I say here is simplistic and not the end all and be all of what you should do or how these system work.

 

[Bestdavidd]

Not if it does not work. One thing is for sure. GM spent millions of dollars for research and engineering and testing to develope this system. My guess is that in doing so they found out that when you change one thing it effects others and so they set the parameters for the ignition so they would compliment each other. Think of a teeter toter that is balanced to keep each end even to the ground. Now add some weight to one end and what happens it goes down on that end. because it no longer is balanced. The same thing happens when you add after market parts. You upset the balance and will have to change other things to get it back. Oh and by the way just because a part is new does not mean it is a good part. Long story short I changed a coil on a car and it would not run over 50 MPH after hours of work I got mad and put the old coil back on and the car ran fine again. Up to then I had believed in the old saying a coil either works or it does'nt. Another point does your friends car run ok with your memcal in it? If it does then my guess is since the memcal is were the ecm stores it short term memory needs his car is giving it the correct data to function. If your car is not giving it the correct data then it will not program itself correctly. Back to the MSD unit if it is not producing the right voltage for higher rpm runninig then the memcal can not forward that to the ecm so it will provide full fuel and spark for higher rpm. Please understand what I say here is simplistic and not the end all and be all of what you should do or how these system work.

John my memcal works fine in any vette, because has the VATS DELETE, like the hypertech memcals... today i tested my ECM and my memcal in a 92 corvette from a friend from a friend of mine, perfect.... 2 corvettes with my ecm and my memcal and runs perfect! So, memcal or ecm not the problem....

Remember if i put the memcal in my ecm, and i start my car in a downhill, my car works PERFECT, everything PERFECT, but, if i let the engine less than 1.500rpm, car just turns off. I put the old distributor in the car that weekend, same problem... so, the msd unit is not the problem.... i put the original coil, original distributor, same problem... starts, turns off... if you accelerate it pumping, stays on... like in the video...

Now im searching the book to see if theres a wire changed in the ecm connectors, if dont, i will take my car to a workshop to reset the BCM or CCM and program it, maybe here reprograming the milleage in the car discontroled the ccm, its a guess because i dont think my car has only 40.000miles.... in my country thats normal, people just put cars that has 100.000miles, on 60.000 miles to sell it faster... and something like that.

If dont, i will buy ALL sensors, all original General motors, ALL the wiring of the car, engine and dash harness, i will buy a new BCM, and if my car has the same problem that i think will be impossible i just will put a painless wiring and put analog gauges in my dash and forget the problem....

I just want to fix my car without expending that quantity of money... but, thinking, its only options i have, please correct me if im wrong.....

I will find the book to see if my ecm wires are in this place, if dont, i will post here again to see that you recommends me to do :eyerole

 

[Bestdavidd]

John my memcal works fine in any vette, because has the VATS DELETE, like the hypertech memcals... today i tested my ECM and my memcal in a 92 corvette from a friend from a friend of mine, perfect.... 2 corvettes with my ecm and my memcal and runs perfect! So, memcal or ecm not the problem....

Remember if i put the memcal in my ecm, and i start my car in a downhill, my car works PERFECT, everything PERFECT, but, if i let the engine less than 1.500rpm, car just turns off. I put the old distributor in the car that weekend, same problem... so, the msd unit is not the problem.... i put the original coil, original distributor, same problem... starts, turns off... if you accelerate it pumping, stays on... like in the video...

Now im searching the book to see if theres a wire changed in the ecm connectors, if dont, i will take my car to a workshop to reset the BCM or CCM and program it, maybe here reprograming the milleage in the car discontroled the ccm, its a guess because i dont think my car has only 40.000miles.... in my country thats normal, people just put cars that has 100.000miles, on 60.000 miles to sell it faster... and something like that.

If dont, i will buy ALL sensors, all original General motors, ALL the wiring of the car, engine and dash harness, i will buy a new BCM, and if my car has the same problem that i think will be impossible i just will put a painless wiring and put analog gauges in my dash and forget the problem....

I just want to fix my car without expending that quantity of money... but, thinking, its only options i have, please correct me if im wrong.....

I will find the book to see if my ecm wires are in this place, if dont, i will post here again to see that you recommends me to do :eyerole

my friends! good and bad news!

That friday, i start the car like all the mornings... car starts perfect... in the evening, i wash the car... and when i start it, just dont start...

Good news! Saturday my friend Ricardo give to me the book, and they appear the plans of the wiring of the ecm, guess what? 4 wires changed, THAT WAS THE PROBLEM MORE THAN A YEAR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! i solve it, i put it in his place like says in the manual...

Okay, the car dont starts, now i have a new problem that i hope be easy to fix.

Car has correct fuel pressure, everything seems to be in order, BUTTTTTTTTTT, car sometimes has spark at the spark plugs and sometimes dont, and when have spark at the spark plugs, has too little spark.

Any ideas? i put a new AC DELCO starting module, and nothing, same problem....

What can be wrong? car told me C12 code that means everything is ok.

Last head exploding failure now is FIXED, now i need to fix that failure and problem solved

Im very happy because i feel im closer

 

[John Robinson]

Do you have the opti back in the car?

When you washed the car did you spray the engine with water?

If the answear to both of these questions is yes then remove the electrical connector on top of the opti and dry it out and then put it back with a liberal covering of dielectric grease.

 

[Bestdavidd]

Do you have the opti back in the car?

When you washed the car did you spray the engine with water?

If the answear to both of these questions is yes then remove the electrical connector on top of the opti and dry it out and View attachment 8224then put it back with a liberal covering of dielectric grease.

thanks John!

i didint wash the engine... and the MSD distributor has the connector in the inyectors, so large....

look at the pic.. so, if i have any problems with water will be if i wash the inyectors, because here is the connector!

i dont know what to do... car says ´´c12´´, i didint scan it with an scanner tool... but my problem is simple, car dont start because sometimes has spark, sometimes dont, when has spark to the spark plugs, has too little spark and its not enought to start the engine...

New ignition module, i tested with other new coil i have, same problem....

any ideas?:ugh

 

[John Robinson]

Check the electrical connector from the msd unit to make sure it is dry and making good contact. I have had that connector on my opti get wet and corroded or not be seated properly and the engine would not run. Recheck all your ground bolts to be sure they are tight and making good contact. Recheck the tps wires for a broken or bad connection. In the fsm read the secton symptoms (In my manual it is section 6E3-B) In other words do not assume anything. I had a BMW motorcycle that would not run and spent two days going over it and finally I discovered that the wiring harness was not plugged into the ECM fully. Pushed it in till it was tight and the bike ran and is still running. So again check everything again and again.

 

[Bestdavidd]

Check the electrical connector from the msd unit to make sure it is dry and making good contact. I have had that connector on my opti get wet and corroded or not be seated properly and the engine would not run. Recheck all your ground bolts to be sure they are tight and making good contact. Recheck the tps wires for a broken or bad connection. In the fsm read the secton symptoms (In my manual it is section 6E3-B) In other words do not assume anything. I had a BMW motorcycle that would not run and spent two days going over it and finally I discovered that the wiring harness was not plugged into the ECM fully. Pushed it in till it was tight and the bike ran and is still running. So again check everything again and again.

everything appears to be OK, tomorrow i will retire the MSD distributor, im SURE its wet! because before dont start car has a little bit failure, when hot, not failure, wet distributor... tomorrow i will have news :eyerole

 

[Bestdavidd]

everything appears to be OK, tomorrow i will retire the MSD distributor, im SURE its wet! because before dont start car has a little bit failure, when hot, not failure, wet distributor... tomorrow i will have news :eyerole

friends! i have more news! problem was distributor full of oil (because i had an oil leak) now i change the timing chain, and all the seals on the engine, no oil leaks anymore!!!

My msd unit came out with NO seal, for that reason was full of oil.


and the other problem was spark plugs full of dirt... and vats activated sometimes, sometimes now the vats activates in the middle of the street, driving, and my car turns off, no spark to the coil, car dont start, i just need to remove the negative of the battery and wait 10 minutes, car starts perfect! When the street is wet, the car do that thing more frequently.

now, problems fixed, car starts again, but same problem, no memcal car starts perfect but you cant pass 3.000rpm, you put the memcal on the ecm, car starts if you accelerate it pumping stays on if dont turns off.

any ideas? any help that you can bring me?? tests, etc...:eyerole

 

[John Robinson]

I believe you said that you now had an FSM. There is a section called Drivibility and Emissions in book 2. Read the section called Symptoms.

I have a question you keep referring to the memcal. Could you describe were this is located as I am not sure what part you are actually removing.

Again in reading the above section of the FSM it will refer (in my 93 FSM at least) to the PROM. A bad PROM or incorrect Prom for the model ECM will cause all kinds of running issues.

 

[Bestdavidd]

I believe you said that you now had an FSM. There is a section called Drivibility and Emissions in book 2. Read the section called Symptoms.

I have a question you keep referring to the memcal. Could you describe were this is located as I am not sure what part you are actually removing.

Again in reading the above section of the FSM it will refer (in my 93 FSM at least) to the PROM. A bad PROM or incorrect Prom for the model ECM will cause all kinds of running issues.

Forget everything John..... this is my car:

corvette burning in caracas part 3 - YouTube

just burned up..... worst car i had in my life, now i NEVER buy a corvette again... if its not a C6 or a new vette... i lost more than 40.000$ in total.... that cars here in my country are suuuuuuuuuper expensive...........

corvette burning in caracas part 3 - YouTube

and my others friend´s 96 vette with me... the car is now that, a ball of carbon....

corvette burning in caracas part 4 - YouTube

Thanks everyone for the help, now, no one can help me because i will remove the engine and transmission and everything is fine in my car and the other stuff to the trash, and im going to sell it for parts.... first time in my life happens something like that... im very, very very sad.... 10 years of hard work to see it burning up in your eyes.....

Now i will buy a BMW M5.... i will keep it with germans... dont have problems.....

 

[John Robinson]

So sorry to see that video. Hopefully you can salvage the engine and transmission. When you bought that car the previous owner had it pretty well screwed up and you were getting close to having it right. Don't blame the car for all your problem blame the guy you bought it from. Now go look for a good C4 and you will have all the spares you need from this car. Most of your problems you inherited and then some you got from people working on it that did not understand the complexities of the electronics. Throw in the after market parts that you used like the MSD unit that was found to have oil in it. So don't give up on the Corvette as a car maybe a newer one would be more reliable. After all there are hundreds of us on this site that have been driving and enjoying ours well into the 100k + mileage. Just the other day I came across a 2008 C6 with 11335 miles on it. It was a blue coupe with a 6 speed and I believe the dealer was asking 28,000 for it.

 

[Bestdavidd]

So sorry to see that video. Hopefully you can salvage the engine and transmission. When you bought that car the previous owner had it pretty well screwed up and you were getting close to having it right. Don't blame the car for all your problem blame the guy you bought it from. Now go look for a good C4 and you will have all the spares you need from this car. Most of your problems you inherited and then some you got from people working on it that did not understand the complexities of the electronics. Throw in the after market parts that you used like the MSD unit that was found to have oil in it. So don't give up on the Corvette as a car maybe a newer one would be more reliable. After all there are hundreds of us on this site that have been driving and enjoying ours well into the 100k + mileage. Just the other day I came across a 2008 C6 with 11335 miles on it. It was a blue coupe with a 6 speed and I believe the dealer was asking 28,000 for it.

yes you are right... maybe i bought the worst c4 in the planet :-( i loved that car because i see it on ebay with 180.000miles and seems like new, mint conditions.... 100.000miles and perfect! I i bought it because its cheap to mantain... compared to my german cars... but now i will take a break to american cars because im very dissapointed... car started in flames and nobody knows why, i fill the tank in the gas station, and 10 minutes later the car explode in flames.... 2 magnaflow stainless steel mufflers (that you can see in the trunk) burned too.. i was going to install it... and look at that :-(

i see my car every day in my house burned and i just want to cry... i really love/hate that car, i loved it because its the sexiest car i had it, even more sexy i think than my SLK 32 AMG. And i hate it because i spent a lot of money in that car and no mechanic can repair it well, in my german cars when something is wrong, simply scan the car change the damaged part and thats all, maximum 3 days my car perfect again.

Well... i think my problem was the VATS, because sometimes has spark to the coil and sometimes dont, and when i remove the entire wiring of my car i see that one of the coil wires goes to the BCM or CCM or VATS.... so vats is: coil, inyectors and starter relay, 3 symptoms of bad VATS. When the corvette see that something is wrong, the car disable the inyectors to prevent flooding of the engine. When the car dont recognize the key code of the car, the VATS disable the starter relay, and when vats its bad like mine, simply disable the coil electricity and you will need to wait 10 minutes since vats restart to start the car.

How complicated and simply is that, i learn a lot of mechanic in that car...and now i share it with us to if somebody has problems in the future has more information to fix it.

And, the ``no memcal and car starts fine´´ and ``starts but if you accelerate it pumping stays on´´ in my car was a failure created by trying to fix the VATS problem.

Thank you everybody for the help, i learned a lot here and i appreciate your help John.

now my corvette is dead, when i buy another corvette in the future if i do that again, i will post here