low speed surging

[Blue89gt]

I just replaced the fuel pump and fuel pump control relay on the car because the pump went out.

I did a complete tune-up on the car and filled it with fresh gas. at 2000rpm the car will surge if i let off of the gas and let the car coast in gear. lower RPM produces the same bucking.

when i am maintaining speed (slight throttle) the car surges similarily as as the coasting.

I cannot figure it out there are no codes and the car other than that runs fine.

could it be the TPS sensor?

 

[stang2004]

I just replaced the fuel pump and fuel pump control relay on the car because the pump went out.

I did a complete tune-up on the car and filled it with fresh gas. at 2000rpm the car will surge if i let off of the gas and let the car coast in gear. lower RPM produces the same bucking.

when i am maintaining speed (slight throttle) the car surges similarily as as the coasting.

I cannot figure it out there are no codes and the car other than that runs fine.

could it be the TPS sensor?

bro my car does the same thing, i asked a couple days ago the same question. might be a page back. I was told its just normal of a 5 speed car.

 

[Ranchero5.0]

Yep, reset the TPS. you may have to play with it a couple times to get it to smooth out. On mine a slight throttle the A/F would go off the scale lean and it would buck. It was worse at 200 degrees after running the interstate. I also set it hot ( a little different than cold).

Jamie

Jamie

 

[blk92stangg]

My friends did the same. We cleaned the IAC, EGR, and the distributor cap and rotor. Ran fine after that. Use some fine sandpaper to clean off the points and rotor, btw.

 

[Blue89gt]

well, the rotor is brand new, i dont belienve my car has points (EFI) and I'll check the TPS today. thanks

 

[stang2004]

i cleaned my EGR and IAC, adjusted the TPS, i have a new cap and rotor and all that.. and the thing still bucks if i dont ride that clutch out. sometimes it bucks hard enought that if i had dentures i think they would hit teh dash at this point i just toss it in 2nd, and it goes away

 

[Blue89gt]

well i took the S/C off today and will be selling it on ebay. the surging seems to be better now that I adjusted the tps.

there is a low speed skip. it sounds like it is missing on one cylinder. i just dont get it. i will be looking at the firing order in a minute. i hope that fixes the problem.

any ideas. it seems like it goes away ofter 2000rpm.

 

[Blue89gt]

well the car actually seems to be skipping at all rpms.

I checked the timing and the firing order, its all good.

Tomorrow I'll check to see if there is spark at all of the cylinders, hopefully there is. I am starting to think it is a head gasket maybe. thier are a small amount of small bubbles in the rad. fluid.

 

[venom88]

I had the Same Problem

I had to replace my TPS i adjusted it a few times and still had problems went to the local store and replace it. No more bucking bronco.

Could also be a broken plug wire