Hello Gents,

Recently my 1994 Z28 will not start. I have good spark when turning over the key(blue spark), at the plugs. The car will fire only once, maybe runs for 1 second sputters, then kills on me. I am thinking the VAT system is o.k. because the starter does turn over(correct me if I am wrong here). I have had ambient problems with the car, have removed the relays for fans 1&2 and jumpered out the fans directly to the 12Vdc from the key switch. I only ran the vehicle this way when I was in town for awhile. Then the charge needle dropped into the discharge area, flickering back and forth. Got the car home, disconnected the fan jumpers, tried to start car and there it has sat. Also when I ran a jumper for the DLC, pins A & B, for diagnostics originally the fans did come. This told me the PCM circuits for fans was good. Now the the fans will not come on when doing this procedure. I am fairly sure the fuel injectors are not being fired from the PCM. I burned chip, get another PCM? Is the VAT functioning? Could use some help on this one.

Thanks much.

debugg2, Monster trans stage 2, CAI, flowmaster 3", MSD coil, JBA wires, bosch plugs, OE rims and tires

 

Not sure what you really did, but did you check the injector fuses, there is one for each bank. Spend $20 on a set of NOID lights & see if the PCM is firing the injectors.

 

have you checked for fuel pressure? Your pump can do its thing and make you think it is working but if there is not enough pressure then you will not be able to start or run. It takes less pressure when the engine is warm than when it is cold. I think that craby may have the pages in his book that will tell you how to check proper pressure.

As for your VATS if you are turning the engine over it is working fine.

The relays should not have caused any issue unless you applied power to the signal side of the relay and fed that back to the ECM, Even if that is the case you should still be able to start but you will get a CEL with ECM failures. I am thinking that the engine not starting and the relays are just a coincidnece.

Massey

 

and it sounds like you have/had a dead battery. you dont have a amp meter you have a volt meter. it will kind of tell you if its charging by the volts but when the gage goes down it means the battery is going dead. whats the battery volts gage say with the key on? it does sound like a fuel pump or pluged filter or bad gas. like massey sayin, check fuel pressure, take fuel filter out and dump contents into a clear container and look for bad stuff. if clean put it back on or change, if dirty change. like pete says check to see if injectors are firing.

 

But def would turn key and listen for the fuel pump. if you have problems have someone listen near you gas door. also a friend of mine said another way to check pump is to take your gas cap off and listen to see if it turns on and then turn the key back off and listen to see if you hear the fuel sounds like its pouring back in then pumps bad even if it sounds like it may be turning on. but I agree with everyone one here. they will solve your problems.

 

Hi guys, VATS. Im sure of it what software are you using. HP tuners???
Vats will fire the car, even when triggered. Vats is anti theft, and therefore cuts your fuel. nearly 100% sure if you know that you have no other issues.

You need to check what codes the computer is throwing, fix them then simply reflash your tune.

I had heaps of trouble when i first started to maflessly ture my car. But it was worth it car was super, and having the software at your fingertips was a real plus.

Hope this helps.