Hairmetal_still_rox!

Well, back after a long time. took the 90 out for a ride with my son. ran fine. came back home went to start it again and it just turns over and does not fire or start. I know the fuel pump is good as I replaced it a year ago and I have a fuel gage on the TPI rail and it is reading pressure, plus I can hear it priming when the ignition is turned over. So....

1. I believe it is electrical, the ECM I think is ok as it was replaced a few years ago and the intrument middle cluster looks normal when turning over ( I suppose it could still be the ECM but not likely)
2. Coil?
3. Distributor module?
4. ?????

What is common here in this situation for bad parts? Anyone lend any advice on experiences or suggestions. I dont want to flatbed this to the dealer as I have done all the work mostly myself for 8 years now.

Input? thanks all in advance from a former service member

FF1wms

Check and make sure you have even power to the distributor.
that will be the wire to the bat term.(with the key on)
Make sure you have good spark and the proper fuel pressure. Pull one of your plugs and make sure fuel is getting to your plugs. If you have fuel and spark and it still wont fire, use a little starting fluid. If it fires then dies, you have too weak of a spark and you should look into your ignition system (cap, rotor, plugs & wires). A local auto parts store should be able to test your ignition modual for you for free. If you should have to by a modual, they are not that expensive.
Don't take it to the dealer, You'll be able to find the problem.

vader86

check the ignition module and the coil first

FF1wms

with Vader on the modual. That 's what I'm thinking that it is.
But...If you dont have power to the distributor there is no need to to go any further that direction until you can figure out why there's no power. It's a 30 sec check that might save you some time troubleshooting.
My quess is it will probably be the modual.
Keep us up to date. Good luck.

excessive81

mine did this at track today....module two months old. on starting line and car just died like i turned it off. then turned over and over. pulled new module out and installed the old one and fired right back up

Hairmetal_still_rox!

Thanks for the replys. you guys are talking about the module in the distributor correct? not the ESC near the a/c and blower box right. This is the 7 pin module? what about the board in there? I will replace the module first though before progressing. I will keep you all posted................

Hairmetal_still_rox!

ok guya, my time is limited ( 3 year old son ) so am just getting back here. I was reading some other posts and decided just to verify it was electrical prior to purchasing the module. Well I hooked up a timing light to two different plug wires and turned her over and I am getting a flash!!! What the??? I am confused now. The pump primed when I started it and shows pressure at the gage on the TPI rail that is normal so what the heck? Can it still be the module ? I dont see how now. What should my next step be here everyone? uggghh

AGENT 86

Have you checked the injector fuses in the fuse panel ??

Hairmetal_still_rox!

I will do that tonight to see, thanks for the idea, how many are there? one for each injector or for each bank? Guess I will find out when I open the panel. I will post tonight after I get home......

AGENT 86

On my 86, there is 1 per bank.

Hairmetal_still_rox!

Ok, checked both fuses 20a and they are good. where should I look next?

RRT vette

You seem to have fuel pressure and spark. Did you try spraying starting fluid in the intake while cranking? You may need to attach a noid light to the injector connectors to make sure the ECM is sending the ref pulses. They originate from the pick up coil in the dist.

Hairmetal_still_rox!

Is the pickup coil seperate from the module in the distributor? Where in the distributor is it located? Also, that is a good point, as maybe the ECM has issues, I replaced it about 3 years ago, this one is a reman from AC delco.

excessive81

your coil may be bad or it could still be the module. mine started once after it went bad for 20 sec so getting spark is not impossible. take the module and coil to be tested to be sure.

RRT vette

Most commonly the ICM (ignition control module) fails when it has warmed up. Thought it is not unheard of...for it to fail when cold especially when the silicone lube was not applied correctly or the connection or wiring is compromised. Autozone can test the ICM for free, but you will need an ohm meter to test the pickup coil.

If a timing light picks up spark going through the wires, it tells me that the ICM is working.

RRT vette

Yes, it is seperate. Maybe you can read this!

trackman44

If the Theft deterent module (TDM, which is part of the VATS system) doesn't read the correct resistance in the pellet of your key, (while the key is in the ignition switch and in the ON position) it wont send the correct signal to the Powertrain Control Module (PCM). The PCM will then disable the fuel injectors from firing when you try to start your vette. The ignition cylinder lock is probably worn out, thus the TDM is unable to read the resistance value in the pellet of your ignition key. There is a work around ( by bypassing the lock cylinder and inserting a resistor to the wires leading to the TDM). The resistor would have to be the same value resistance as the pellet.

Hairmetal_still_rox!

thanks guys, I will test the pickup coil tomorrow morning. I think I may just replace the module to be sure but if the timing light is showing a spark passing through the wire I think that is working but will know for sure. The TDM issue scares me as I wouldnt know how to test or repair unless someone has a specifiec procedure? The info given already is great just the same. thanks all again

Hairmetal_still_rox!

oh, also, I will pick up some starter fluid and squirt some in the intake to see if it fires too and if it doesnt I will pull a plug to see if it is wet. this should help narrow the search. I will post tomorrow after doing a few of these things..........

trackman44

Here is a link to VATS problem.

http://sethirdgen.org/vats.htm

Its possible the VATS module ( or TDM module) has gone bad or its fuse blew. Check its fuse in the fuse panel. If its still good then the TDM module is bad and needs replacing.