worked on interior all winter now tring to get to run right. car wont idel when cold. had a bad ecm replaced. also wires, plugs and dist.my first corvette. has 23000 miles but it was in bad shape. also when i bought it the owner said it will not start at all sometimes told me to take out theft det. module so i completly took it out. my horn doesnt work and the door locks. will i have to put the module back in to get them to work.

 

I just went through the no idle thing. Describe exactly what it's doing.

The rest I don't know.

Do you have a FSM? If not that's the first thing you need to purchase.

 

yes i have a fsc. the car is in afriends shop but he doesnt know much about vetts. he keeps saying it is a cold injector. i dont know if it has one

 

What year is it?

I don't know what year they quit putting the cold start injector in them for sure.

Mine is a 90 and it turned out to be the IAC (Idle Air Control) I'll look for my thread on it and post it up.

 

the car will start and idle if you hold your foot on excelerator or i put a screw driver on throttle body to make it idle until warms up then runs ok.the archives is sending me to the icm.

 

the car is a1989

 

thank you very much iam new at this

 

Read this. Does it sound anything like it. My cure is a few posts down from the top I think.

http://forums.corvetteforum.com/c4-t...ue-solved.html

It's at post 8

 

Here is a pretty good post on the ICM. Your symptoms do not sound like a bad ICM to me.

http://forums.corvetteforum.com/c4-t...-symptoms.html

Do this. It's what I did to figure out the IAC.

Take out the IAC. Clean it throughly with carb cleaner and an old tooth brush. Or you can use your good toothbrush if you wish

Then clean out the cavity where the IAC goes by spraying the cleaner on a rag and wiping out the cavity good. The wipe out all carbon, you can get to, in the throttle body.

Also take note when you take it out and look to see if the IAC is extended or it is contracted. In my case it was fully extended and and stuck thus not allowing any air in.

Put it back in and see if it idles. When I did this it didn't idle 100% but it did idle so I knew this was my problem.

this is a no cost thing you can do unless you have the equipment to test the IAC. As a thought also. If your car will start with throttle it can't be the cold injector, if you even have one which I don't think you do.

Also keep in mind if it is the IAC something has probably caused it to get gummed up. More than likely a rich fuel condition.

Almost forgot. When you reinstall the IAC you will need to reset it. You do this by starting the car and hold a little idle for 5 seconds. Then you turn off the car while still holding the throttle. Wait ten seconds and then restart. That will reset your IAC.

 

Yes, put the theft deterent module( all it does is activate horn) back. It's the VATS module that will stop you from cranking and disable injectors.
The pellet in key, is read by the VATS module. If it's happy, it will allow cranking and injection. You cannot remove the VATS module. You can trick the VATS module, by unplugging the 2 wires going to ignition switch and putting resistors of the correct resistance, between those 2 wires.
This site will help with that, if it is VATS that is causing the problem.
http://www.joestradingpost.com/vats/

Cleaning the pellet on key, may help.

As stated, your idle problem could be linked to the IAC.
Test it to see if it's working.
http://members.shaw.ca/agent86/IAC%20Diagnosis.pdf

You may also want to try and set the minimum idle and TPS.
http://www.lbfun.com/warehouse/tech_...ch%20Paper.pdf

 

Sounds like it could be injectors,,Watch the video below and do what it says..The 89 Corvette had Multec injectors that are known to go bad when ethenol is run through them over time.When mine went bad my car wouldn't idle at all and had a definite miss. Even if it ends up not being injectors if you still have the Multecs in the motor you will eventually have a problem with them.Also check them when there cold and again when there hot, reading should be around .016 both times...WW

http://www.youtube.com/watch?v=_g8Pd...layer_embedded

Here is another one, not a professional video but it gets the point across..

http://www.youtube.com/watch?v=ValTYJUfPA8

 

Open up the ECM, read the letters on the chip, and find out if it is the correct one.
In 1989, they programmed out the start injector, and programmed the injectors to provide cold engine fuel until the temp sensor tells the ECM that it is in closed loop mode, and can fully regulate with all the sensors.
Your symptoms sound like somebody put in a 86-88 chip, and it is asking for a cold start injector that's not there.

 

That's definitely a possibility!

 

How we doing with this issue?