my car has been in the shop for 3 weeks. it started to drive rough, took it to shop they found a loose wire on the fuse box..problem fixed...two days later i park the car and it never started again...took it back to shop, told was not getting a pulse to the injectors..replaced control module, no start..replaced ecm and prom...car started, shut it off and it never started again...checked and replaced all injectors..still no start..replaced all relays, still no start..checked vats system, no code, and no flashing security light... pulled the front pass side fender well and checked all wires to ecm..no start... the shop has given up on my car and giving me a very large bill.. ANY SUGGESTIONS WOULD HELP. OR IF ANYBODY KNOW ANYONE I CAN CALL. PLEASE HELP ME.

 

this is one of those things where if it was my car, I'd keep chasing it until I got it running, but you're paying someone else to chase it for you, and that's so costly it's dumb. This is a job for someone who has owned one with the same engine, and knows what to do with a DVOM.

 

i agree fully and im kicking myself.. i live in a small town and there are not alot of options. this is my 1st tpi and did not know they were so funny acting. i dont know where to trace next ive followed all suggestions of people on this site and still got nothing but a big repair bill for an unrepaired car..and after the first problem (ecm replacement) it started right up, we shut it off and it never fired again..so what do we trace? im picking the car up from the shop today but there is nobody around that knows what to do with the car..next step is to put a carb on it and take the ecm out. problem is i just bought the car for 3500, spent another 1000 getting it (not fixed) and only got to enjoy it for about a month

 

Well i couldnt help but notice your in a bit of a hard spot and i dont know if i can help but i do deal with electronics so ill see what i can do. Now you say that the car had the ECM replaced and it started just once. Now i suspect a few things right off the bat. 1) maby the ECM wasnt bad but you have a bad connection or 2) pehaps something unrelated is killing the ECM. For starters its time to check over the ECM connectors and see difinitivly why the car isnt starting and if it turns out to be the ECM then i would guess we should take a look at the charging system. You might be supprised but alot of things can cause electrical surges that can destroy electronics. For example have you ever noticed that electronic component in the commector on the AC compressor? The reason thats there is when the windings in the compressor are dissenguaged the collapsing magnetic field acts like an ignition system generating a high voltage spike. The diode allows the energy to be dissipated in the field itself effectivly shorting it out but it werent there then your electrical systems would see a spike and electronics dont like that kind of stuff. There is a similar situation in the alternator. However first lets see whats wrong and try to figure out what caused it. A few questions for you first how familiar are you with a volt meter/mechanical skill (as i have a feeling this will be an interesting onel lol)? Have any mods been done? Any work that was done prior to this problem?

 

im picking up the car today $785 and still no start. according to the mechanic he has checked all grounds, leads wires ect and cant find anything. the car is stock, i have mech skills and can read a volt meter, just no time i work 70 plus hrs a week. I DID HAVE A CD PLAYER PUT IN THE CAR, car ran fine for a week then all the problems started

 

Well although it may be total coicident that the radio was installed and then a week later the car dies i would deffinetly give it a good look over. Was this just a regular radio right not like a whole sound system for subs or anything crazy like that? If you have the old ECM we may want to try that again because im not completly convinced its bad as crazy as that sounds. Just because it happend to work after it was replaced dosnt guarent that that was the problem. From there i would first check your timing and make sure you have spark we need to figure out exactly whats not happening to cause the car not to start and thats a good start. I know how it goes with the whole time issue and i can say this problem can be tracked down and probably repaied cheaper than swapping to a carbed set up but it will be very time consumeing concidering the odd nature of this problem.

 

from what i can tell and been told the car is not sending a pulse to the injectors..replaced everything around it, ign. module, relays, ecm, prom, injectors..im told that there is nothing else the shop can do except pull the wire harness and check all wires. the bill is now over $800 dollars and still no start..what should i do..and to answer the question it was a stock radio put in no subs or amps.

 

Well for starters i think we need to recheck and confirm that the injectors are recieving no pulse. Like i always say trust but verify. Becides so much has been done to the car we cannot assume thats still the problem. From there if it is still the problem well just have to trace this problem back to the ECM and if the ECM turns out to be at fault again i think well have to check out the electrical systems to see if maby you have some kind of a power surge thats frying the ECM. I would also try pulling the fuse to the radio not really removeing that from the system entirely but its easy to do and i am always suspicious when work is done and shortly after a problem starts. Also you dont have any kind of vehical anti theft device system installed do you?

 

no extra vehical security, just the vats..also checked that out..as of today the car is still at the shop still no start. i dont trust the shop anymore as they cant answer any of my questions and get upset when i ask them. i will get it home this weekend and try some of the things suggested and let you know what happens.

 

Yea its hard to get a good shop. Especially for these cars because alot of mechanics are great with new stuff but they dont see cars like these anymore so natrally knowledge about them kinda gets lost because its not really needed. Not so bad that its fuel injected but try bringin in a carbed car. Thell be as clueless as if you put a jet engin in front of them. None of my cars have ever seen the inside of a shop as result. Now its interesting you mentioned that you have the factory VATS system because the way it works is it will kill off the injector pulse if its not happy. How did you test that system?

 

just checked the security light. it does not stay on when cranking the key

 

Well we may want to look deeper into to that because even though the light dosnt stay on lets say the vats system sees everythings ok and turns off the light dosnt neccessarily mean that the ECM is getting the everythings ok signal. Havnt owned a camaro with vats yet so ill have to look alittle deeper into how everything really works but the problem your describing is just what a vats system will do if theres a problem.

 

Ok after looking over the schematic heres what i see as a potential problem. Now the VATS light is controlled by the VATS modual so as long as the system is functioning as it should this light will operate as normal. However there is a signal wire from the VATS decoder that sends a 30 hx or a 50 hz puls to the ECM to tell it to enable the injectors. If this wire was broken or had a bad connection the security light would go out because the system is working fine but the ECM would never recieve the everythings ok signal and will not start.

For more info and the shematic:

https://www.thirdgen.org/vats_passkey_system

 

its running and driving right now!!!!!!!!!ROLLING THUNDER IS THE MAN!!!!!!!!!!THANK YOU ....AND AGAIN THANK YOU

 

What was the problem in the end?