I need your help. wierd problem?!?

[kreske]

Ok to start off with i have a 1996 240 with a black top SR, it has many upgrades to it ...wideband o2 sensor, map sensor, power FC, Greddy profec e-01, GT3071 .63, 650cc injectors, ect. So anyways the problem is i was driving home on the freeway the other day and out of nowhere my car started to sputter under acceleration like it had a excessive rich/lean condition. so at first thought i thought i might have done something internally but my compression was 155 across all cylinders. so then i thought it might be the fuel pressure regulator, since it was the stock one, so i replaced that with the nismo adjustable and the problem still exists. when i pulled the plugs they were really black and black smoke comes out of my exhaust under acceleration, it smokes at idle as well and it seems like it is misfiring with a horrible idle. I dont know what could have happened or gone out while i was driving so if you have any ideas it would be greatly appreciated.

thanks

[seanman]

excessive fuel eh? run your ecu and see if a code pops up

[kreske]

I checked my ECU and nothing came up. do you still go through the same process to get the trouble codes from the power fc as the stock ECU?

[90_240sxx]

did you check for leaks? because that can make your car runs pig rich

[seanman]

yeah, telling the pump to push more out.

[xekushnr]

Well its definitely running rich. Check your injectors and make sure they are firing correctly. Did you work on your car just before this happened?

[blinker_fluid]

check your ignition coils

[seanman]

i assume you have a walbro or some sort of higher performance fuel delivery?

[kreske]

Yeah i have a Warblo 255 pump. my coils are all firing and the injectors are all working correctly. would a leak before the map sensor really matter though? i would think that having a map sensor leaks would really not be a problem, unless i guess there is a leak in the manifold...hmmm i will try checking that out.

[kreske]

So i checked my manifold and there was nothing that appeared to be leaking and all of my gaskets looked good. i checked my power fc to see if the fuel tuning has changed but everything is the same as it was before. I am stumped...

[kreske]

bump...

[MagnumP_I]

do you still have SMIC? If so you might have stock blow off valve still down there which could be causing a leak if you are running 2 blow off valves. Sounds Stupid but my friend had that problem when he bought his S13 with SR Swap already the previous owner didnt know what he was doing.

[kreske]

no i have full 3 in. piping and front mount, a leak in the IC piping would not make that big of differance because i am running a map sensor.

[kreske]

Well the problem is still not solved, i am being deployed for a few months starting tomorrow so thank you everybody for helping out

[seanman]

so my car starts! but there too seems to be excess fuel cause it will idle just fine but it emits alot of excess fuel smell. I'm thinkin i need an adjustable fuel pressure regulator?

[Zilvia33]

hmmm my car stutters when i press teh throttle, but very lightly.

if i press it more than 20% i dont have any problem. but under that it feels like its stuttering