Some obscure issues here.

[Cat Fuzz]

This has been bugging me for months now and I'd really just like to try and fix it.

94 Rodeo 4x4 3.2L. Engine hesitates just enough to really annoy me when I accelerate. Also, if I hold the pedal steady at just higher than idle, the engine will surge and slow at a regular interval. No CEL ever since I've owned it (few years).

I've recently replaced the spark plugs and wires, pcv valve, cleaned the throttle body, air filter is fine. Just got done replacing fuel filter.

I have a hard time accepting that this might be normal. So, if someone could really get their noodle reved up on this one and help me figure this out, I'd really appreciate it.


EDIT: Also recently ran some Sea Foam through the fuel injectors.

[amigo-2k]

how many miles? Was it your first time using a gas additive to clean the injectors?

-Ryan

[Cat Fuzz]

124K

Never used fuel additives. I followed the directions on the can of Sea Foam and poured it directly into the throttle body while running.

[amigo-2k]

Unfortunatly that will not clean the injectors that way. You can add sea foam to the gas, but at 124k I think it could be a bit risky, since you may free up some crud in the tank.

Your best bet is to spend the cash and take it to a place that will hook your fuel rail up to a can of cleaner so you won't need to worry about adding stuff to your tank.

I had a truck that did the same as yours. I risked it and ran three tanks of gas with a fuel injector additive. The method where they hook a can of cleaner to the rail is the best way to go.

-Ryan

[Cat Fuzz]

So, you really think its just dirty injectors?

[amigo-2k]

rereading over your post, I see you have replace all of the normal things to fix your problem (key ones, plugs, wires and fuel filter). The only other thing it could be is a vaccum leak somewhere (I'm not sure if you have a bunch of vaccum tubes).

-Ryan

[explicit408]

Any updates on this? I think Im having the same issue when the engine is warm.

[Ramblin Fever]

O2 sensor??

[Cat Fuzz]

I never did figure out what the problem is. Still does it. Still annoys me. I have ruled out, tune-up items, MAP sensor, EGR valve, TPS. If I had a nice data monitoring scan tool, I could probably pinpoint the problem.

[kb2nto]

I had a problem like yours. Replaced the throttle position sensor didn't help in my case. Turned out to be a loose connection on the fuel pump at the tank. Maybe this will help . I am told a bad throttle position sensor will cause this problem...Ed

[Cat Fuzz]

TPS is good. Checked it with a volt meter.

[2eyefishclaw]

I had a trooper that did this it annoyed the hell out of me. The really bad thing was no codes and I work on these things for a living, my wife would hound me for it every day. I finally decide one day after some deep thought to try cleaning the IAC valve did not help so I replaced it my stupid problem was finally gone

[corning_d3]

I would guess either the fuel pump is getting weak or an O2 sensor is getting slow and lazy. Just my 2 cents..

[trooperbc]

i've been following this thread and. . .i am going to repeat 2eyefishclaw's post above just so it doesn't get lost in the shuffle, with added emphasis. thanks 2eye for the answer !!!

Originally Posted by 2eyefishclaw

I had a trooper that did this it annoyed the hell out of me. The really bad thing was no codes and I work on these things for a living, my wife would hound me for it every day. I finally decide one day after some deep thought to try cleaning the IAC valve did not help so I replaced it my stupid problem was finally gone

//bc

[Cat Fuzz]

Does the IAC valve do have an effect on anything off idle? I don't have an idle problem, its off idle, out of gear when it fluctuates. No fluctuation while driving.

It's been doing this since I bought it 5 years ago.