I cant get the car to stay running, and i cannot figure out why.



the symptoms:



Car will start every time, jump to about 2k, and sit there for a few seconds. It will then procede to just drop RPM smoothy till it just dies. If you try to nail the gas, it dies. You have to feather the gas pedal to keep it running.



If you let it sit for a while, and try to start, the car will stay running. I had it going for about 5-7 min today. If you touch the gas, it dies.



I have basically changed everything over the winter, so its going to be hard to track down the problem.



Here are the mods i performed:



-dual walbros

twin relays with direct 12v power, grounded to the battery

-550/1600

-aeromotive FPR set at 40lbs.

-I am getting a steady fuel pressure according to the gauge.

-xst04s kit (shouldnt make a difference)

-blocked off everything emissions/stock related

-AEM CD2i

-Power FC with a BRAND NEW engine wiring harness

-removed double throttle system



I have the stock map loaded into the PFC, that should not be the problem.



I dataloged one of the cars cycles, and nothing looks out of place. Good 13.5v power untill it dies...nothing out of the norm...



Grounds are all attached and look fine.



I cannot find any obvious vaccume leaks, and i sprayed carb cleaner around the manifold when it would stay running with no change in idle RPM.



the 550's are not leaking.



I cannot think of anything that would make it run like this. Please help :(

just replaced the relays...same exact ****.

Have you tried it without the AEM?

yes. The AEM harness has a loop connecter to eliminate the box. Same ****.

did you punch out the pins from the harness?

fuel filter?

You sure the coils are firing?

No, not yet. Shouldnt be the problem yet tho. The old harness did have the wires cut, witht he same result.





Have two new fuel filters for each feed line from the walbros.





I'm pretty sure. What is the best way to test the coils?

so once it is running as it starts to die does the fuel press trail off? sure the pfc is set up correctly? check coils just by pulling a plug wire and grounding it. ohming will check the primary resistance fwiw. tps, iac?

Found the problem. There is sopposed to be a filter in the line to the map sensor. I had a check valve...but i think i have pictures of it being like that before the motor was pulled...when the car was running. Who knows, but its fixed. Now the idle is going 1000, 2000 up down up down non stop



but the car runs



and i took it down the street



woot

Suxors!



They look a lot alike.



Sounds like you still have a big vacuum leak? https://www.nopistons.com/forums/pub...R

That sounds like part of my problem as well.I just now realise that I did not put the check valve back in the line. I am using the GM 3 bar, are you using the same and what filter did you use? Why cant you use the stock moget?

make sure you dont use a check valve. I have a filter in there now https://www.nopistons.com/forums/pub...IR#>/happy.png



And tyson, that is what i thought...



But i cannot find any vaccume leak. I checked every gasket..every block off plate



i tried the carb cleaner trick arond all of it (raised the idle to 2200 where it stayed solid to try this) and couldnt get the idle to raise at all...

I think a lot of people had this with the PowerFC!



I only had the PowerFC and aftermarket fuel system together for a single 2 hour drive and it did that too.

It revs up and down because the PFC is learning the sensors and ****. It will do that for a while.

How long generally would you say that the PFC is learning?

IT should only do it the first time the car starts up, and it generally takes like 10 min with no lights on, 10 min with the rear defroster on, and 10 min with the a/c on ( IF that) for it to learn the idle adjustments

i've never had my idle hunt when i installed a powerFC. Usually was a small vacuum leak or a bad ground.



Make sure to double check everything. After your idle smoothes, you can adjust the idle with the PFC or the idle set screw.