have fuel and spark but still wont start

[bobbyc69]

I just installed a like new comp in my 97 firebird. it has the 3800 v6..i have good fuel pressure and spark but it wont fire, its like the injectors wont work..does anyone have any idea what the problem could be

[techsan23]

Re: have fuel and spark but still wont start

I'd start by making sure your getting a signal from your crank and cam sensors.

[Mirwin]

Re: have fuel and spark but still wont start

And that everything is plugged in snug

[bobbyc69]

Re: have fuel and spark but still wont start

yeah it is , the only thing ive done was plug the new comp in and now it wont start

[techsan23]

Re: have fuel and spark but still wont start

Why did you change computers? It sounds like it would start and run with the old computer installed.

[ssms5411]

Re: have fuel and spark but still wont start

Why did you change computers? It sounds like it would start and run with the old computer installed.

I would agree , install your old pcm and see if thats the problem.

[bobbyc69]

Re: have fuel and spark but still wont start

the old comp was bad kept throwing a up a miss fire code on # 4..i don't have the old one its gone. I got this one offline at a web site for car and truck comps.

[techsan23]

Re: have fuel and spark but still wont start

Do you know what vin# is programmed into the new computer? That way you can verify that its compatible with your car's year, engine and transmission for starters. Given that its a match if you have access to a scanner you can scroll through and see if the engine's sensors seem to be reading reasonable values like the MAF, MAP, TPS, IAC, O2 sensors etc. It will also allow you to see if you are getting an RPM reading to the PCM when you turn the engine over. There is also multiple grounds in the PCM connectors that you could test to make sure you have good grounds running to it.

Another thing you might have already checked, but do you know how much fuel pressure you have at the fuel rail?

Did you change anything else besides the computer when it went from starting to not starting?

[ssms5411]

Re: have fuel and spark but still wont start

When you ordered your pcm did they ask you if you had a manual or auto? Also whats the part # on the pcm? Did they ask for a vin # (doesn't matter too much aslong as its the correct trans and gear for your car). But if they got your vin it would show them the correct tranny and gear you have. If you have someone you know with Hptuners they should be able to add you to their license and flash your pcm with the correct file. If not I have Hptuners for all of 97' pcms and have 3 extra pcms lying around, so if you need another one I can flash it on my car with your tranny and gears and any other mods and send it to you. Just a option , PM me if it comes down to that.

[bobbyc69]

Re: have fuel and spark but still wont start

techsan23, I have the correct fuel pressure for that car. no I haven't changed anything else...I cant remember what I told them when I talked to them..i might have told them it was an automatic. i have the obd2 scanner, is that what your talking about? ssms5411, im goin to check on afew more thing, then ill let u know...thanks..

[techsan23]

Re: have fuel and spark but still wont start

Did you purchase the PCM from an individual or a vendor? Most of the vendors test their computers to verify that it is a working unit. Do you know if the VATS function was disabled?

[techsan23]

Re: have fuel and spark but still wont start

I think the VATS is actually triggered by the BCM rather than the PCM, but I thought I'd ask. You would also have a security light on the dash and no fuel pump. If your scanner will do more than just pull a DTC, you can usually ID the PCM and see what VIN is programmed into it, and look at data coming from the engine sensors.

[htmabe]

Re: have fuel and spark but still wont start

techsan23 is right about bcm controlling vats. if it's a vats problem it's easily fixed by bypassing the entire vats system. If you know your key number or chip value you can even purchase a plug n play vats chip