This sound familiar to anyone?

[russ]

1996 GMC Safari. Upon normal acceleration vehicle will hesitate/sputter slightly while gaining speed. While cruising at highway speeds, if I press the accelerator completely to the floor and hold it there, the engine will keep running but the rpms drop almost to an idle and the vehicle will just start to coast and slow down. Just like if you were going down the road and slipped it into neutral. If I slowly let the accelerator back up about 1/4 of the way it will accelerate again. Make sense to anyone. Thanks.

[Deep]

Plugged fuel filter or plugged exhust.

[leech~~]

Maybe an intake vacuum leak?

[1968]

Could also be a TPS problem.

[Jeremy airjer W]

Dirty or bad MAF sensor would be my first thought. Unplug it and see if the problem improves.

[katophil]

fuel injectors

[pureinsanity]

Could be several things, seems like the bases was all covered. No Check engine light on?

[mechanico]

TPS, throttle position sensor. Any one know how to spell that? one or two t's. MAF is mass air flow sensor. Any way, with a truck that old, start with the easy stuff. I agree, could be a lot of things, even O2 sensors. First check all the sensor connections, and ya might disconnect the battery while you're doin' that. You don't want to blow off your air bag.

[MJ1657]

TPS, throttle position sensor. Any one know how to spell that? one or two t's. MAF is mass air flow sensor. Any way, with a truck that old, start with the easy stuff. I agree, could be a lot of things, even O2 sensors. First check all the sensor connections, and ya might disconnect the battery while you're doin' that. You don't want to blow off your air bag.

Huh?????

[Jeremy airjer W]

I agree, HUH??????

[mechanico]

Waddaya mean, "Huh???" Mid-90's GM's were bad about electrical problems. He didn't mention black smoke out the tail pipes, so I assumed it wasn't a problem with the throttle body itself. Nobody mentioned the possibility of a partial fuel clog or pump problem either. And since he did mention the engine seemed to slow to idle speed when he steps on the gas, but didn't didn't mention if he was already rolling, we can't even guess about the torque converter lock-up do-hickie. Ya know what? A vacuume leak could cause it too...I change my vote to electrical connection OR vacuume leak.

Later taters

[MJ1657]

Huh???????? I hope you are messing around with us.

If you are it's kind of funny, if not i'm a little nervous.....

[mechanico]

What's your guess MJ1657?

[Jeremy airjer W]

My first Huh was the "Disconnect the battery as not to blow the airbag". I have never been able to measure a drop out on a TPS with an ohm meter and I quickly found out that it is much better to test them with the key on (so there is current running through them) and then back probe the signal wire and use either a voltmeter or a lab scope to check signal voltage.

My second Huh is why would the torque converter have anything to do with this?

[mechanico]

Oh, I see. If you're not experienced at tracing wire harnesses you could unplug and plug the wrong thing and blow off the air bag. And watch this. Russ, do you know how to check the drop out on a TPS? The point is to check all the connections in the circuit.

And, if the torque converter lock-up solenoid isn't working right you can over-rev, or stall out...depending on whether you're at speed or slowing...like that. The symptoms can fool someone who hasn't experienced it.

Any how, what's your guess?

I'll check back tomorrow 'cause it's almost 1am here.

[Jeremy airjer W]

Most manufacturers do a pretty good job at hiding the crash sensors for the airbag. The front crash sensors are usually located as for forward on the vehicle as possibly to give the most time to react if there is a collision. If your unplugging crash sensors to check TPS sensors than you're in way over your head! Even if you unplug a crash sensor with the key off not much is going to happen. With the key on it will set a code and disable the airbag. So I'm not really sure where you are going with that.

If you want to share some ideas that's what we're all about. If your a little more knowledgeable than the average DIY'er than give some examples with explanations and reasoning behind why you think those are possibilities and maybe even a quick tip on how to test.

russ never mentioned anything about over revving or stalling so I'm not sure why the torque converter would be suspect.

I think we have provided a pretty good base of possible solutions based on the information that we where provided. Plugged fuel filter, dirty MAF, and plugged catalytic converter are all reasonable possibilities. These can also be prevalent without a check engine light.

Until russ replies and answers the questions asked or gives us an update as to what he has found we have done about all we can.

[mechanico]

Russ, the votes are in! The guessing has you pegged anywher from a novice to an experienced auto tech. AND since proper observation of the symptoms is aslo dependent on said...PLEASE tell us what it was after you figure it out, and maybe HOW you figured it out.

Thanks much!

[SFC]

Huh???????????

[tonkapat]

plugged cat?

[Jeremy airjer W]

Huh???????????

Yup!

[russ]

Took it in to a couple places and no one could tell me for sure what the problem was, could be this, might be that. (no kidding! that much I know) But for a few hundred we can probably figure it out. So since it was just latest in a list of issues I just pushed it off a cliff. No more hesitation or sputtering problems. Thanks for the reply's.

[mechanico]

genius