my car is running like shit... i have a custom turbo kit, 14b, sfmu, 30# injectors, warbro 255, msd ignintion/coil, accel wires, stage 2 cams...i think thats all you'll need to know
anyways, the car never ran perfect...it always had a stutter, then started pulling....then about a month ago, if i floored it, the car would buck like crazy...if i eased on the gas, it would run ok... i tried, crank/cam sensor, map sensor, checked plugs, wires, coil, bypassed the msd, nothing....then the car started running better out of no where....it would still stutter, but now had a lot more balls.... if i would ease on the gas until the stutter stopped, then i could floor it and it would drive fine.... well the one night i was at a stop light and decided to hit it pretty hard...so i dropped the clutch at about 3500-4000 rpms and then the bucking started again....the car lost power, bucks, backfires, anything but run good...i dont get any CEL's either.... im completely lost....will the sfmu do this? is there something that could go bad in them? how about a fuel pump? could i be running rich, or lean? the backfiring and loss of power makes me think rich.... any help is appreciated...thanks
doug

how old are your front and rear oxygen sensors? mileage on the fuel filter? spark plug type and gap?

edit: does uit do it when the motor is cold? or only when up to operating temp? clean out the egr

Got a fuel cut defender? Missing Link, VC1, or similar?

run a voltage test on the primary 02 sensor.


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know me as santiago
boosted 420a and ej2o..(my 2liter v8 eaters)

Timing belt jump a tooth?

I have same setup, and have not experienced anything that bad, but close. Try your coolant temp sensors as well. Mine actually broke, and made the car have similar symptoms, poor idle, running rich, backfires. I replaced and it seemed to fix. I would check all of the above mentioned things as well.

edit: I just remembered my car did buck wildly once. It turned out that one of the wires to my afc(long gone now) was loose, and when the engine tourqed down it would move it. Don't foreget to check the loom of wires by the egr tube.

i have a missing link, and im a 95(dont even think i need the missing link)... front 02 sensor is new...rear one im not sure.... i didnt think it really did that much anyways...i have iridium plugs and a set of NGK's...neither helped or hurt.... ive checked my wire loom and couldnt find any burnt/melted wires... coolant temp is fine...i have a pocketlogger and its reading the temperature fine.... any other ideas...?
thanks
doug

I hate these stupid gremlins. How about the msd unit? Get rid of that stupid missing link, you don't need it with a 95.

Coolant temp sensor is different from what you see as a temp reading on your gauges. Its the one that screws into the front of the thermostat housing. Sometimes that can cause hesitation etc because that one actually sends a signal to the ECU. The other one just displays you coolant temp on the gauge. So check that out.

Other than that, you do not/should not have a missing link on a 95.

This may be a long-shot, but, when I did the EGR block-off mod, all of my hesitation and bucking went away. I woulsd try that too.

Good luck man!!

remove the missing link from the system. thats your problem.

ive tried it with and without the missing link.... i know there are two different coolant sensors.... the pocketlogger actually picks up the reading that the engine sees...not the one on the dash...which makes no sense to me why they would put two in there... the msd is bypassed already and it didnt fix anything..... anyways, i tried disconnecting the fuel lines to the sfmu, made sure everything was flowing well, checked the diaphram, and disconnected the battery to reset the ecu...the extreme bucking is gone, now its the normal hesitation.... its only like a hesitation between 2~4k rpms....once i pass that, the car runs like a champ... if i try to downshift within the hesitation, the car will buck.... but if i downshift at like 4k rpms, it will haul ass....could this be a fuel pressure problem? my theory was that it took a while to build fuel pressure up, then once it was up, you could floor the car.....any thoughts on that?
doug

i believe the pressure is full before the engine even starts, when you turn the key to ACC/ON, you can hear the fuel pump priming