I have a 94 with a rebuilt motor with all new OEM seals and new rotor housings. Current mods are...Biltz stock mount intercooler, Power PC, Apexi air intake, Bonez down pipe and cat, 1300cc injectors, AST tank, Koyo radiator and Racing Beat cat back.

Engine has less than 1000 miles on rebuild, I have babied the engine and did not get into to the boost. Changed the motor oil yesterday, car ran perfect all day yesterday.

Started car this morning, engine runs really rough and will eventually stall. Very small amount of white smoke from tailpipe. Boost gauge bounces when engine is trying to idle, gauge shows about 14 to 16 inches of vacuum if I hold the idle at about 1000 to 1200 rpms. Engine has all new vacuum hoses, plug wires and plugs.

I am having my car towed to my shop and will perform a compression check. I can't imagine it is the engine because it was just re-done. Is there anything else I should look at.

Thanks...

 

Have you checked the spark plugs and spark plug wires yet? Especially the wires are wounderable to high boost.

Another thing that can make your engine sound like it is blown is a leaking/blown hose to the MAP sensor or maybe the MAP sensor itself is blown...

But it's smart to check the compression as well, because then YOU KNOW 100% if your engine is blown or not.

 

I will check the plugs and plug wires when I get to the shop. When you say MAP sensor, do you mean the boost sensor on the firewall? If so, the vacuum hose seems fine. What sensor code should I look for on my Power PC to check voltage for the MAP sensor?

 

Just got done checking compression and found all is normal. Plugs looked fine but I replaced them anyway. Started the car again with new plugs, runs the same.

I then reset the Power PC to default factory settings, started car...now runs normally. The idle jumped right to 3000 rpm then almost right away dropped to 1000 rpm. The idle was a little rough for about 5 minutes then cleared to a nice smooth idle. Before the PC was reset it never jumped to 3000 rpm when cold (I understand this is normal). I took her around the block and she seems to running fine now. The only thing is when I turn on the AC, everything is fine until the AC clutch disengages, after that the idle hunts to about 1200 then drops then back, does this about 10 seconds then settles. It doesn't do that when the AC clutch engages. This also was not an issue before the PC reset, I am guessing that I will need to get the Power PC tuned again to my mods.

Anybody else have this issue with the Power PC? The car ran perfectly yesterday until this morning then bamm after the reset runs perfect again.

 

yeah you have to do the full idle air volume learn.

let it run for 10mis all loads off then turn the ac on for 10 mins the turn the rear defrost on for 10 mins and the turn on the headlight for 10 mis then turn all loads off and should idle fine...if not the you migh have ti mess around with the idle settings on the pfc.

and did you move the idle adjuster screw at all?

 

^^^I did exactly what you said and played with the pfc a little. I had the fuel cut on the AC and AC with electrical loads set to low. Now my car runs perfect. I will have her dyno tuned this Thursday and will post the results.

I am still puzzled about how badly she ran this morning out of the blue. Reseting the pfc fixed it...weird.

...revhardallday...thanks for the info.

 

For a second I was starting to believe you really thought it was called Power PC instead of Power FC haha. Glad you fixed your problem.

 

LOL! I was really stressed this morning when I started the thread, I wasn't thinking straight...I am just glad it is not my motor!

 

No problem ... anything to help anyone out on this forum is my pleasure!!