Jerking hesitation - Sort of urgent

[Hartman]

Hey guys, yesterday my CEL came on while I was driving to school. I didn't notice anything abnormal other than some mild jerking/hesitation when the truck was coasting and sometimes when I was accelerating. If you shut the truck off and restart it, the light does not come on until you drive for a few minutes. I tried to get the light to come on with the truck in park and revving the engine but I was unsuccessful. I'm thinking this is a fuel management problem, possibly a clogged fuel filter?

I know I'm not giving you much info to work with but if anybody has had these symptons or has any ideas on what could be wrong I would greatly appreciate it!

It sucks not having OBDII or I would simply scan the codes.

 

[Runnin'OnEmpty]

Hartman, I believe the 95 model year started the OBDII. Regardless of it being OBD I or II, you'll have a code stored in memory since the MIL came on. Get the code, and we'll give some suggestions.

Maybe a TPS or MAF problem.....?

 

[MrShorty]

Officially, OBD-2 didn't start until the '96 model year. I've heard there might be a few '95 OBD-2's, but never confirmed.

It sucks not having OBDII or I would simply scan the codes.

Personally, I prefer OBD-1 for getting codes; the code reader is cheaper. OBD-2 requires some kind of scanner (at least $50 and easily lots more). OBD-1 requires only a paper clip (~1 penny), though I like to use my $3 analog voltmeter as the code output device (see www.dalidesign.com/hbook/eectest.html) And pulling the codes is the best place to start.

 

[Hartman]

Well I do have a port underneath the steering wheel and my truck is a late model 95, but I doubt it's OBDII. I will scan the codes soon and see what the heck is wrong.

 

[Hartman]

That site confuses the hell out of me.

 

[james t]

Could be a fuel delivery problem (old clogged filter) or a spark/ignition problem. Really hard to tell without further info. Keep us updated.

 

[MrShorty]

That site confuses the hell out of me.

I've pulled codes like that a lot, and find that a pretty good description of how to run the self-tests. What do you find confusing, and maybe we can help straighten you out?

 

[Nate1]

Hartman, whats your computer look like under the hood?

Could also be O2s, but I agree, it sounds like a fuel delivery problem, so it's kind-of blind guessing.

 

[LOGJOCKY]

well use a lube...OH you mean vehicle jerking...sorry. aint i redfaced.

 

[section525]

I'm going to vote spark plug wire/coil pack problem.

 

[Hartman]

Hartman, whats your computer look like under the hood?

Could also be O2s, but I agree, it sounds like a fuel delivery problem, so it's kind-of blind guessing.

My computer looks like any other computer 96-01. Comp code is FIG2 which from what I understand is the 2nd updated version to come out in 95. The earlier computers in 95 were FIG1.

 

[Garth]

With Section; Wires and plugs.

 

[Hartman]

Wouldn't bad plugs and wires cause a rough idle? My idle has not been affected at all, it is fine. I thought plugs and wires would cause some sort of knock or ping.

 

[Garth]

I had a similar problem where as I would start the vehicle, everything seems fine but a soon I put it in gear, step on the gas, the truck starts to feel jerky/hesitant when moving off.

Whenever I am on the highway going at speed the cel would flash, then go back off when I slow.

At highway speed you can always feel like the truck is missing something through the rpm cycle.

 

[Hartman]

Replaced fuel filter today, not the problem. Back to square one.

 

[Runnin'OnEmpty]

Garth, Hartman, you guys really need to get the code(s) read. Simple OBD II code readers can be picked up for around $60. They won't pinpoint the trouble like scanners will, but they'll at least suggest an area to look at. It's really hard to diagnose a problem without the trouble code.

Hartman, MrShorty is correct in saying OBD II started on the 96 models.

 

[Hartman]

I do plan on getting an OBD I scanner. I think it's either the O2 censors, fuel pressure regulator, or plugs and wires.

 

[Garth]

Thats the first thing I did (change the fuel filter) and it was as clean as a whistle. The exhaust smelt different and I thought it might have been the cats or the o2, maybe even a vacuum line. Was the wires & plugs. Now, if only I can find the pvc.

 

[Hartman]

I went to Autozone to get the code read today. They couldn't scan it because the light goes off after you shut the truck off, and you can't read the code when it's idling. :fire:

So I'm pretty much stuck. I'm not taking it to a mechanic. The truck drives fine other than it is sluggish and has some very slight jerking on accel. It bugs me though because the truck is noticably sluggish. I'm leaning more and more towards plugs and wires but I don't want to keep replacing parts that don't neccessarily need replacing!

 

[huskyfan23]

If you decide to do plugs and wires, I say run some Seafoam Motor Treatment through before doing them.