Down & Out

[garycr14]

Well I had just got my car on the road on Wednesday afternoon, dorve it Weds evening, all day Thursday, then it dies going onto the freeway in the evening. I would like some thoughts on what you all think the problem could be. It was driving normally, then just died. No strange sounds, thumps, jerks, or anything else. It has almost a full tank of gas. It appears to be getting fuel into the carb. The previous owner told me that he had replaced the fuel pump & filter. I haven't checked the spark yet as it happened late last night. Again it was driving fine and just died. I have just replaced the spark plugs, rotor, cap, and super coil. Any thoughts would be great. I have not picked up a manual yet (hopefully today), as I have not been able to find one locally, so I am working a bit blinded.

Thanks!

 

[Harv]

Dont know if this helps but, I had an old Cadillac that did the same thing. What happened was there is a small pan inside the gas tank that the pump and sending unit sit in. This pan came loose and was sliding around in there it slid into the fuel pump and caused it to short out. (assuming our vettes have in tank pumps, someone help me here?) It was still getting a little gas to the engine but not enough to run.

 

[81 Corvette]

with just that tid bit of info, i would check to make sure you are getting spark and gas. Both easy enough to do. Work your way up the system that isn't working.

 

[trent81]

I would check rotor.....

Trent81

 

[garycr14]

Didn't have a chance to work on it today, thanks for all your input so far. I did a quick test this morning, shot some starter fluid down the carb. Didn't even pop, so I have a feeling it is electric. I'll check for spark & work my way back from there, I saved the old Rotor, Cap & Coil, so it will be easy enough to replace the new with the old tp see if any of the parts are faulty. I'll keep you posted in the next couple of days. Wont be able to do much over the weekend as I will be seting p the autoX course for Sunday. Good thing I have another car that I race with!

 

[evariste]

Did you try to open your gasoline tank ?

One of my friends had the same problem with his Vette. Air could'nt enter the tank. When he opened it, it was like opening a vaccum sealed can...

 

[GerryLP]

Evariste,


I could be wrong, but this is the first time I have seen you post something in a long while. Welcomed Back!!!!!!!!!

 

[evariste]

You are right GerryLP.

I was not away. I have a look at this forum every morning.

But there are so many high skilled people here that I had absolutely nothing to add.

 

[RC81]

Check the ignition module in the dist. When it goes you will get no spark.

 

[drags1998]

Throw the supercoil in the trash can, then try it!!!! It sounds like a heat related problem to me. with this little info its a tough to tell Good Luck!!!!

 

[garycr14]

Well I was able to look at it some today tested for spark, NO SPARK. I put the old cap & coil back on and still no spark. I replaced the alternator thinking that the voltage regulator could have went bad (voltage reading at the gauge would spike into the red when over 1000 rpm), but did not help. My Chiltons manual is almost useless very little in the way of troubleshooting. I have ordered a new module (last week) should be here anyday. Are there any fusable links that anyone is aware of that could be the cause? Any thoughts? What is a good manual to help get me through this, and future problems (just in case)?

:confused
Thanks!

 

[Macgyver]

Do you still have your computer hooked up then, obviously since you were looking for it? try unhooking the plug from the puter to the distributor and then see if you get some spark. The four prong wiring harness that plugs into somthieng coming from the firewall. I had quite a few no spark and just plain quitting on me problems. it does kinda sound like a heat issue but then again Im just learning. I would pull off of the highway and it would just quit on me. Somtimes it had gas and other times it didnt in the inline clear filter. my problem was that i had a leak and there would be no coolant. Sensing this from the coolant temp sensor the ECM would shut the enigne off for a good embarissing 15 minutes. sometimes at a light and sometimes in a convenient spot. After filling the coolant i still had a problem becuase the coolant temp sensor had exposed wires and when the engine reached reg temp sometimes it would still cut the enigne off which i solved by repairing the wires. theres more, Somtimes when idling at a light it woudl die when id try to accelreate after turning green after solving the overheating issue. reving it hard after restatring it would bring it back to life after a minute but i suspect that the computer was giving a bad signal to the TPS on the q-jet. but then again its late and Im just rambling.

Try unhooking the distrib to see if it fires up or you get spark. Also use the volt meter and touch it to the Bat wire going into the distirb with the key on. Try it w/ the ecm and w/out. if you got 12v there then you know its the distrib internals or the ECM not letting it spark. If you dont have 12v there than test the bat again and check the fuse link there. I think Mike (stingray6974) told me that its a fuseable one from the starter.
And get yourself the 81 shop manual! i love it when everyone tells me this. I still havent hehe. Theres none on ebay right now but they usually go for $50. Half of it dont apply anyomre since i ditched all that ECM crap. well at least the confusing part. i grabbed the haynes amnual for the C3 and that has helped alot. $12 dolla at autozone. no matter what dont tow it in somewhere unless its your daily lol. CCA will figure it out.

Heres this though if you got 12v. >>> http://www.chevelles.com/techref/ftecref5.html
half way throuhg that page theres some tech stuff on diagnosing an HEI that Brusso gave me. pretty good stuff.

 

[black_81_vette]

Well I had the same thing happen to me.sounds like a bad pickup coil in the distributor.Bad part is you have to pull the dist out then pull the shaft out of to remove the pick up coil.

 

[garycr14]

Thanks for your responces thus far. I have replaced the capacitor & termanal block, this insolator was cracked, but not the problem, tested for voltage to the distributor, it is fine. I have a new module comming, should be here on Thursday. I am hoping it is not the pick up coil, as I don't look forward to pulling the distributor. I feel like I'm stabbing in the dark here. Is there a diagnostic tool available that will pull the codes from the computor?

 

[Macgyver]

Yeah there is but youlll be hard pressed to find one I think since its like the only made for like 2-3 model cars during a 1-2 year period i believe. what you do is jump two terminals on the plug under the tray. I used a screwdriver. If you look closely you see that one corner of the plug is different from the rest. On mine it was the bottom right corner. The wal between these 2prongs is smaller or absent so that you can fit a screwdriver between them. Put screwdriver in and then turn key to on position but dont crank the motor. The check light will flash code 12 four times mening its going into diagnostic mode. One long (~) and two short (..) pause, and then repeat. After that it will tell you the problem in flashes.
http://www.iequus.com/assets/manuals/gmcre.pdf
this says 82 vette is covered but they should work I believe

 

[garycr14]

Macgyver, thanks for the input, I didn't know how to read the codes. Unfortunitly in this case only the code 12 flashed, which of course means no codes stored. Seems to be thae way this is going to go for me, everything the hadr way. But I am not giving up yet. The new module will be here Thursday or Friday, I'll pop that in and pray! In the meantime, I am certainly open to any suggestions.


Thanks!

 

[RC81]

Wait untill you try the module before proceding with anything. That way you can rule out one thing at a time. I still think thats your problem. The computer would show a code if something was wrong with it and even then you would get spark but no starting. Keep us informed.

 

[garycr14]

Yee Haaaa!

It was the module, as we all suspected I believe. Thanks for all of your input, it's great to have a lot of heads to bounce things off of. The next fight is the spark plug wires. I'd like to knoe who the idiot was that designed the routing on these. I installed 5, with the last three to go, but I am going to pull out the ramps so I can have a bit more access from undernieth the car. I used jack stands, but would have liked a bit more room to roam.

Thanks again everyone

Gary

 

[Yoda]

Gary,

If your car still has the heat shields installed around the plugs... I found it easiest to take them off and YES you need access from underneath to route the plug wires as the "GM Engineers" designed them to go

While I had the heat shields off I cleaned them up and then look almost new amazing what a polishing wheel and a dramel tool can do

Glad to hear you got some spark back in your step

 

[like2drive]

the same thing has happened to me. On my vette, it was one of the 2 wires, under the sparkplug rotor..just dropped and did the same thing you described. Spotted this, hooked it back up, and away we went.
The second time, also pulling onto interstate in my truck, had the same thing. Had to be towed home. Manual led me to the module, which was the problem. Hope this helps.