Hey guys need help figuring this one out.

Car=1992 Camaro with 5.0 TPI.

Issue=No injector pulse

I've checked d12,d6,d7 &e15 grounds at the ecm as well as injector grounds c11 & c12

Injector Grounds c11 & c12 have 32 ohms resistance when key is off, when key is on they have zero resistance. Is that normal?

I also checked pickup coil resistance & it is 812 dizzy & ICM is new. ECM & prom are new. Injectors are also new.

Both injector fuses are good & there is power going to them. There is power at the injector wires as well. Both the dark green and dark blue have power going to them with key on.

Vats has been disabled by wiring in the correct resistors. Security is blinking off & on. SES is also on indicating power to the ECM. Fuel pressure is 42 with key on.....

I'm at a complete loss at what to check next guys. I'm really hoping you guys can tell me what I missed something, cause whatever it is has to be the problem. I've checked & re-checked all of the above. Any and all help is appreciated. Thanks

 

Security is blinking on and off. This pretty much says it all. Vats problem. Check your resistor selection and all connections. You did plug the resistor in to the connector going back to the vats module and not the steering column?

 

IIRC The security light blinking off and on indicates that the VATS system is working as it should. When I disconnect the resistor I do not get a security light at all. My key has 7.48kohms of resistance in it & I was able to put together 7.45kohms worth of resistors together, & yes they it is going back to the vats module.

THX

 

I don't know the answer but I imagine it lies in one of these sentences. I'm thinking VATS as well. Someone with good VATS knowledge will have to chime in.


I'm straight guessing, the new ECM and PROM are looking for a different resistor value than what has been bypassed?


https://www.thirdgen.org/forums/elec...ing-tuned.html


http://www.austinthirdgen.org/mkport...m_pass-key.jpg

 

I believe the way vats works is it receives the correct resistance value from the key to the passkey module decoder which then sends a signal to the ecm telling it to fire the injectors. The ECM/PROM do not receive resistance value, passkey module does. ECM just looks for the signal/wave, thats generated once the correct key/resistance is sent to the passkey decoder module. The signal it looks for does not change between ECMs/Proms since they are exact replicas of the originals....

What I dont know for sure is if there should be that kind of resistance in the two injector grounds....

 

After reading the diagram, it looks like the ECM receives 5v signal from passkey module saying to fire injectors (your correct, no resistor value to ECM).

 

When I purchased this car it'd been converted over to carb. WE are currently converting it to TPI & the only thing standing in our way is this damn injector pulse issue! Im guessing this is the reason the previous owner converted it over to carb from TBI in the first place.

Is it possible the passkey module located behind the dash has gone bad all together?

& does anyone know what the bosch relay part# 12034544 does? Its one of the relays under the kickpanel that I cannot identify... Could this be the starter enable relay? Car will crank with key, but not consistently, so I rigged it up to start to a switch directly from the starter...

Anyways I'm thinking of just order a prom with VATs programmed out. I feel like its the only thing it can be. We bypassed the resistor for the key & it should be sending the signal BUT if the passkey module itself is damaged it will not work.

Anybody have any thoughts on what else it could be?

 

 

Kick panel is starter relay. To bypass connect the two heavy gauge wires together.

 

Bypass the starter relay, (its already bypassed before the module, let's just take the module out of the equation on the starter side) engine should crank normally. You can verify the it's the correct relay via the "Austin" link in post #4 by wire colors. Looks like DK GRN to YEL.

Then check for 5v on DK BLU wire (same diagram link, ignition switch:run) between decoder and ECM. If there is not 5v, and has continuity of wire, tight clean connections, decoder module is bad. By manual, "replace decoder module", but the Tunned Performance tune at $35 would be a better solution imo.

 

There are 4 wires going to it but the colors do not match. I believe the colors on mine are green, a thick yellow, a thinner guage yellow & purple with a white stripe.

Going to look for that blue wire tomorrow and check for voltage. & yeah 35$ to disable vats sounds a lot better.

I thought I had to buy a new prom from pcm4less for 100$ to get it done tho. How do I get it from tunedperformance for 35$? Do I send him my current memcal to have him program vats out?

 

The colors change every year iirc, but it will be the two heaviest wires. With the Tuned Performance tune the starter relay will still have to be bypassed. Check for the 5v cause if its there the tune most likely won't work.


I can't vouch for TP as I have never used him, nor can I tell you how his service works. However, he is on my friends list just shoot him an email or pm, I'm sure his service is pretty painless.

 

So the problem was VATS all along. I got a chip burned from local member 1bad91z and it fired right up.

He also touched a couple things to help optimize the performance of the car and deleted EGR and AIR

Thanks for all the help guys...

PS: I would highly recommend him if you are looking to get a TPI tune.