View Full Version : S13 'DE bucking on cold starts

11-16-2005, 12:09 AM
Hi folks,
I'm racking my brain trying to figure out what's wrong with my 240. On a cold start(**no matter if engine is warmed up or not**), the car bucks violently in 1st-2nd with constant accelleration. If I push the clutch in the RPM's stabalize and there is no bucking. Problem goes away after about 5-10mins of driving. It's so bad I have a hard time keeping constant gas pedal pressure. If I try to accell it hesitates but will stop bucking, untill the speed is constant again. I have gone over SO many things, and I'll try to list/remember them below.

-rebuilt DE, past break-in, everything stock except suspension(shocks/springs). Good compression
-checked proper EGR/BPT operation.
-good vacuum at idle(roughly 21-22hg)
-cleaned MAF, re-grounded
-swapped TPS, re-calibrated
-new OEM O2 sensor
-new coolant temp sensor
-cap/rotor on their way(OEM)
-new NGK(BKRE5) plugs, 0.04" gap
-spark plug wires ohm'ed out
-stock injectors ohmed(11ohm each)
-idle fuel pressure good(although unsure about running pressure)

-baseline dyno reports slight lean mixture, but that's at WOT so it may not matter. Expected stock output power.
-CONSULT diagnostic read-outs. No codes, all the sensors seem to be in check

Any ideas? Please feel free to throw out any suggestions, even though it seems I'v covered many bases! If I thought a dealer could find the problem in a few hours I'd bring it there, but I can't afford a $$$ diagnosis.

11-16-2005, 10:09 PM
bump for some help! My 240 is becoming not-so-fun to drive anymore!