Dug Strickler

Need to know what the PCM needs to satisfy it to send spark and injector pulse signals. Everything has power(injectors, pumps, starter, ect) and motor turns freely. Cam and crank sensors show they are working. There is a "VDT FUEL ENABLE SIGNAL" wire that we are not sure if it gets power or grounded but were pretty sure that it is required... it is dk blue on pin 30 on the "red" side. I am sooo close but I mostly need to know what the PCM needs. Any help would be GREATLY appreciated. Please help me get this thing started. You can check out my car here. Volvette

crewchef

iTrader: (6)

PIN 30 on the Red plug is tied into the VATS if I'm not mistaken. I'll try to look the circuit up in my manual and post more info later.

65chevellels1

iTrader: (5)

sounds like a VATS problem to me. I had a problem with vats where the car would start for about 1-1.5 seconds and instantly quit.. wired in my vat's bypass, and also removed with HP tuners and worked perfectly

crewchef

iTrader: (6)

From my 98 service manual but I assume it's the same basic circuit.

Circuit 229, DkBlu, runs from BCM to PCM. The BCM enables the crank circuit to the starter and sends a signal to the PCM if the correct key is being used. If the proper signal does not reach the PCM on the fuel enable circuit, the PCM will not pulse the injectors ON and thus not allow the vehicle to continue to operate.

I don't think this is your only problem though. Normally if it's a VATs issue it will start but only run for a second or two. If you're getting no spark and no injector pulse there's something else going on too. Are you getting in DTCs?

crewchef

iTrader: (6)

Couple of other thoughts. You said everything has power. Check to make sure you've got power while cranking too.

Probably already doing this but just in case. Check grounds at the individual connectors to make sure you're getting good ground.

How are you testing for spark?

Here are a couple other checks out of the manual;
Have you got good fuel pressure when cranking?
Fuses - INJ1, INJ2, Eng Cntrl, Eng Sen, a/c cruise (not sure about the a/c one?)
Showing RPM while cranking (scan tool)

Dug Strickler

Pardon me but what is DTC(s). Thanks

Dug Strickler

Yes I have power while cranking too. I have good fuel pressure. Testing for spark by unhooking a coil wire and plugging in another spark plug with a good ground.

crewchef

iTrader: (6)

Diagnostic Trouble Code (I think), should be able to see these with any data logger or scan tool. If you don't have one you probably need to find someone local that can loan you one or scan your car for you. A DTC code will tell you what kind of problems the PCM is seeing. I think there is a sticky here somewhere that you can cross reference the code to the problem description.

Dug Strickler

I will be using this tool on Sunday. THANKS CREWCHEF!

crewchef

iTrader: (6)

Link to the sticky post with a couple DTC look up sites.

https://ls1tech.com/forums/pcm-diagnostics-tuning/209783-need-lookup-ses-code-look-here.html

Good luck with it.