Peeduhh

iTrader: (5)

I have a 93 FD3S with a fresh rebuilt motor I overboosted it from 5lbs to 16lbs and it started idling roughly. Vacuum gauge is steady but idle is choppy but when moving it drives normally. It sounds like an ignition problem. I really hope it's not a blown motor again. Any idea to what could be the problem?

Tem120

iTrader: (5)

did you over boost it while breaking it in? , and if not. how was the car tuned?

Peeduhh

iTrader: (5)

the car was broken in and tuned for 5lbs i swapped the wastegate spring and it spiked past the 14.50lbs the spring was intended for and then it started idling rough. Can anyone confirm if that would throw off the plugs?

Tem120

iTrader: (5)

no that would not throw off the plugs . timing would be controlled by the ECU , i'd check for some vacume leaks . What turbo do you have that you only tuned it for 5 psi? what power was it making at 5 psi?

what stand alone do you have?

if it was ignition ( and it can be ) it would be due to a component going bad , plugs , coilpacks , wires

Peeduhh

iTrader: (5)

There doesn't seem to be a vacuum leak, the boost gauge would be jumpy if that was the case (i could be wrong). I have a GT40R and it was making 380hp the last time it was tuned. As for stand alone I'm using the power FC.

Tem120

iTrader: (5)

a vacume leak say you have hoses without clamps , a vacume line could of easily popped off ( although i'm not sure what it could be on your system ) if that vacume line pops . you could have a constant vacume leak which wouldnt really affect your vacume infact may even make it higher . and the PFC is trying to compensate for it. using the idle air control .

can you describe in detail what you mean by idling roughly

ALSO , doesnt your PFC have any safety settings?? how did it get so high PFC should of cut fuel

Peeduhh

iTrader: (5)

It sounds choppy when it's idling almost like it did when the resistors overheated but when it revs or is in motion it sounds fine.

Tem120

iTrader: (5)

whats it idling at when you rev it are the AFR's fine?

Peeduhh

iTrader: (5)

it idles at 1000 at normal temps. it dropped down to 5-600rpm when it started getting choppy and built the revs back up to 900-1000rpm and is still choppy and response is to throttle is slower than usual. and yes my AFR is fine.

Tem120

iTrader: (5)

honestly I dont know . I'd try checking the plugs first replacing them if needed . if the vacume is the same as it was before . then it shouldnt be a blown motor.

Peeduhh

iTrader: (5)

Sounds like a plan, I'll do that first. Thank you for your suggestions!

Peeduhh

iTrader: (5)

so i was checking the spark plugs and it seems like my primary plug in my front housing was loose, i hand tightened it and it helped a little, I hope when I tighten it fully after work it'll fix itself.