Ok before I get hounded I did a search first and didnt find what I needed.
Background I have an 88 GTA 5.7 auto that is now a manual and I recently installed a new engine and I switched to speed density. I hooked everything up right and I have spark but it looks like I dont have any injector pulse so I am not getting fuel. The car cranks just fine but it doesnt even try.
I am thinking it is VATS related here as I bought the memcal for a 91 vette. My 88 doesnt have vats at all so I am trying to bypass it altogether so there is no buying a resistor here. I have the shop manual for 92 and it shows that if VATS isnt working right then the injectors dont pulse. I have the diagram for the circuit and it looks like if I ground the blue wire that goes to the I/P then the ECM will see the correct signal?? I just want to be sure that it goes low and not high, or to +5 VDC.
Or could my problem be something else altogether?

Thanks

 

no one has any ideas? or was it locked?

 

Ok, this is the way to find out if it's a vats problem:
The engine shouldn't even crank when the key is turned.
The security light should go off about two secons after turning the key to the ON position
I'm pretty sure that the Vats system can be bypassed by making a jump on the ECM, The car won't crank unless the ECM gets the proper resistance from the key pellet.
You can check if the locking cylinder is reading the resistance by putting the key on the off position and unplugging the two yellow wires from the black conector and plugging a voltmeter set up into ohms.
I'll send you some info on the vats system and troubleshooting.

 

thanks for your help but you need to read the post again. I dont have VATS in my car. I just want to know if I can bypass the whole thing by grounding the dark blue wire on the 92 harness.

 

You got me lost there!!!
Let's get his straight:
You think it might be the vats but you don't have the vats???
Or is it that you have the vats harness in your non-original-vats car?

 

Hello hesgone2fast,

What scooter is saying is that he has put the memcal from a 1991 corvette into a 1988 GTA which was not set up for the VATS system. However the memcal for the 1991 corvette is programmed to look for the proper response from the VATS control module which is not present. I believe that what he needs to do is replace the computer in his car since he is switching from a MAF system to a MAP system. I also do not believe that the 1991 corvette memcal is compatible with the 1988 GTA ECM. Just a thought! BTW, have you got your problem resolved?

The Trickster!!!!!!!!!!!

 

yeah you got it trickster, mostly anyway. I converted the engine to speed density so I have the 7730 ECM now and the memcal from a 91 vette.

Unfortunately no i havent figured it out yet. The car is at my grandparents 180 miles away. I called and asked my grandfather to try grounding the wire but he hasnt been able to yet. Hopefully he will try tomorrow

 

Ok, I got it straight now!
Yeah, I can almost tell you for sure that the memcal from the corvette will not be compatible with the GTA's ECM.
My problem with the Vats has not been solved. As long as my car starts fine the first time, It'll be just fine.
I don't really know where my problem is.
But thanks for asking, Trickster!! BTW, I checked the resistance on my key with key on the off, ans still got the same as I told you: 3,05 K ohms. Does this make sense to you?
Sorry Scooter, you might be wondering what's wrong with my car, or you might know the answer:
When I start my car, it fires right up the first time, but if I shut it off, won't start back until 2-4 mins later, engine cranks, security light goes off, but doesn't fire. Doesn't matter if engine is hot or cold.
Any thoughts??

 

Wow I have no idea, maybe the fuel pump thing? Like when you put the key in run pump primes then when you turn off then on again it doesnt prime again until you crank. just a thought

 

To hesgone2fast,

See if you can borrow an ECM like yours from a friend and try that in your car to see if the results are the same. And yes the results from your multimeter are about right. Now take your key and the multimeter and touch the probes to the metal contacts holding the pellet in the key to see if your readings match your previous readings. Good luck!!!!!!!

The Trickster!!!!!!!!!!!!!

 

Thanks Bob, I'll keep you updated when I check it on monday, I only have a multimeter in my wharehouse where I work