Engine bucking like crazy, only sometimes? (Page 1/3) Benn2002 APR 21, 06:57 PM Hey guys, I feel like I have become a regular on here now after only having the car for 2 weeks but it is what it is. So I was driving my 1988 fiero formula (has a 3.1 roller cam block with bigger injectors and a bigger TB and an egr delete--idk if it matters or not) last night, pulled into my neighborhood and stopped at a stop sign. I put it in first to pull away and boom, it starts bucking, engine light turns on, car is essentially controlling itself. I would push the gas and it would cut in and out and in and out. The bucking was pretty bad, totally undrivable like that. So I pulled over, shut the car off, started it and it was back to normal....and I was hoping that was it.... So I get home from work today, go to take it out, I made it a few miles down the road, I stop at a stop sign and put it in first gear, it happens again, same thing, very bad bucking, I managed to make it off the road (barely). I did the same thing, turn it off, wait a few then turn it back on, and everything is fine. (Engine light is back off) I don't think it has to do with the clutch or anything transmission wise because it goes into first, then when I try to press the gas, that's when it happens. It is almost as if someone is giving it 1/4 throttle, and letting off, over and over again. Engine braking, and then accelerating. It's bad I do not enjoy it haha. You guys have any idea on what this could be? I have absolutely no clue and don't even know where to start. Extremely Thankful for any help or insight! I just want this fixed! Neils88 APR 22, 05:34 PM Without going through the entire diagnostic list, you should start by checking the obvious items; vacuum leaks, loose wires/ grounds. If this doesn't turn up anything, then you'll need to start confirming individual systems; fuel, spark/ electrical, air, etc. Patrick APR 23, 01:02 PM quote Originally posted by Benn2002: ...do you guys know if that would turn my CEL on? Because when this symptom happens, it turns on for the duration of it,. If I turn the car off and back on again, it runs fine and normal. But the CEL is OFF again, so I don't think I can even read what the code WAS saying. Did you try? The trouble codes are stored. Benn2002 APR 23, 03:11 PM quote Originally posted by Patrick: Did you try? The trouble codes are stored. I need to buy a code reader, im going to do that after work today and check and see what it was. Also another idea I had was the TPS sensor? Could that be linked? It seems like it doesn't know where the throttle is suppose to be and then tries to do something- that's not pleasurable to experience. cebix APR 23, 03:38 PM In my experience bucking = EGR problems. Do you have an EGR? Benn2002 APR 23, 05:10 PM quote Originally posted by cebix: In my experience bucking = EGR problems. Do you have an EGR? I do not have an egr and it's not tuned, yes I know it bucks pretty good going under 25 because of the egr, (I just ordered a new chip should be here later this week) but that is not causing this, this seems unrelated from the egr. It never did it before, then 2 consecutive drives it did it, after it was running fine for 30 minute's each time, hence why I'm so confused, makes me lean forward something electrical. phonedawgz APR 23, 06:08 PM Bad motor mounts can cause a bucking effect. Benn2002 APR 23, 07:18 PM quote Originally posted by phonedawgz: Bad motor mounts can cause a bucking effect. Can't be that. When I say "bucking" it's more as the car takes full control over the gas pedal and pulls itself ,then stops, then pulls, then stops, etc etc.. Motor mounts would be all the time too, I would imagine, this only has happened 2 times, although I have not driven it since the second time because It can't happen on the main road...(yea it already did...that was NOT a fun experience let me tell ya) Patrick APR 23, 07:50 PM quote Originally posted by Benn2002: I need to buy a code reader This is the high-priced piece of hardware (with minor modification) that I use to read codes. fierofool APR 23, 08:19 PM quote Originally posted by Patrick: This is the high-priced piece of hardware (with minor modification) that I use to read codes. I had to skip 2 days meals and got one for each of my 2 cars. I love them because they are so compact that I can keep them in the door pocket or the dash pocket. The batteries seem to last forever, too.