Top Swap issues...
 

Hey guys, I know a few of you have done top swaps.... I just finished mine. I have an issue now though. She started up and ran fine for about ten minutes, there was a coolant leak from an elbow, no biggy, shut it off, restarted fine twice. So then third startup, the car started to run like crap, and finally stalled. The car wouldnt start up anymore unless the throttle was opened a little, and as soon as I let off the peddle, it would stall... It sounds like the onboard security system, I have a ZZP PCM, I just got a response on club GP from a guy who works there who had the same problem, and said disabling security fixed it, any you guys have any issues or know the security relearn for our cars or if this wille even work?

starting issues.
 

If you turn the key, and hold down the gas a little bit, will the car start and run?

Will it stay running as long as you have your foot on the gas, but die as soon as you take your foot off of the gas?

That's what it sounds like you're saying.
If so, I don't think you have an electrical problem.

-Riggs.

Dumb question and you did the top swap so I'm sure you thought of it.

Is your PCM programmed for the top swap?

no,the car no longer starts...It startedup, and ran fine for 5-10 minuteswith a solid idle,revved a few times, no problems, and restarted a few times fine as well. Then the idle started to get rough, and finally cut out, and to get the car running again I ahd to press the gas down to keep it at around 1500 rpms. Then this didnt even work. From what I can tell its the security systemon the PCM interfering, and yes, its a ZZP 1.0 PCM with the tables adjusted for a top swap. Anyone know of a fix? or to check something?

i know it sounds dumb but did you plug your coolant temp sensor back in, i remember when mine was shot on a different vehicle i had this was the issue i was gettting, as soon as i let off the gas the vehicle would stall. its worth a look

yup its plugged in haha, I had to swap the sensors cause of a different pin out. so its in, definately. I checked it just now as well.

what motor did you go with what did you start with and what did you finish with??

heads, S/C (Eaton M90, replaced the coupler and oil myself), fuel rails, off a 98 bonneville
coil pack bracket, standoff, from a grand prix, ordered from morad parts company. PCM from ZZP. Tables adjusted for top swap on a 2003 Monte Carlo. Fel Pro gaskets all around, TB off an 00 grand prix, throttle body spacer on there... ummm I think thats all... injector connectors I soldered myself, on there solid... looks like PCM from everything. the car cranks, so its not stuck in hydrolock.

As far as I've ever seen, if the PCM is causing a no-start security issue, it will let you know.
Usually when the security issues happen, it will flash the security message in the information center box.
It also will not crank the motor when it is the security system, it won't power the starter so you don't get any turning over at all. No clicking sound of a bad starter either.

From your initial post, I though that sounds like a big vacuum leak.

Did you check to see if fuel is actually getting to the engine while it's cranking?
Maybe one of the injector connections shorted out after a few minutes and is causing the engine to not get fuel now?

-Riggs.

A friend of mine had this problem on one of his avengers. Could be an IAC valve, EGR valve, or maybe just a clogged up fuel filter?