[KitRittyTug]

So, under acceleration the truck jerks. In gear, but with no gas, it all seems fine. It also seems fine in neutral giving it gas, but you never know still. A minor hiccup could be all what is happening that is unnoticeable in neutral.


I was wondering if a loose drive belt, or a bad belt tensioner could be causing the jerking. My belt is sqealing at idle now. I put belt dressing on that did nothing, and my belt tensioner I have noticed is making a strange noise that I have never noticed before. You don't even need to put your ear in the engine bay to hear it.


Looking up online, there is a HUGE check list that needs to be done, and it is really going to suck. Just thinking I should take it to a mechanic.


I recently got a new fuel pump, and fuel filter 4 or 5 months ago now, so that shouldn't be it at all. I put injector cleaner in the truck, and it seems to already be working, but I am skeptical. Some startups the truck is way worse then other start ups, and I think that I have just been lucking so far.

The distributor cap and rotor in there should be off the check list as well. It is currently raining, and it has been acting a lot better the last two start ups today. It has acted way worse on one of our drier days. So I don't think that it is a moisture issue.
Plus are 5 months old, wires are like 18 months old.

I would say it has been doing it for about a month now, and it is really starting to piss me off.

I also have no engine light. I have also checked, and need to recheck my vacuum lines. Though they were all fine when I checked first, and I can't hear any vacuum leaks either.


Anyone have any insight? Would be much appreciated.

[sbgctsa]

can you clarify "jerk"?, mine stumbles a bit under acceleration ( 86 c10), but ive got vaccuum leaks like its goin out of style lol

[KitRittyTug]

It feels like I am on a bumpy road, though am not.

Kind of like a forward / backward kind of thing.

[SarSerceSaice]

just to clarify... it sounds like your belt isn't squeaking... the bearings in your tensioning pulley have probably gone bad... you will need to fit a new one.

This will not have an effect on the way the engine runs though.

As for the way it's running... could be a lot of things. Can you connect a reader up to it?

[CIAFreeAgent]

sounds likes it is mssing to me id look at plug wires and cap and plugs but its hard to figure it out when im not there

[KitRittyTug]

just to clarify... it sounds like your belt isn't squeaking... the bearings in your tensioning pulley have probably gone bad... you will need to fit a new one.

This will not have an effect on the way the engine runs though.

As for the way it's running... could be a lot of things. Can you connect a reader up to it?

That sucks. $35 down the drain to really just fix an annoying noise.


I wish I could do the reader, though it is a 92.

[eXC3Kvnn]

It's your MAP sensor. Same thing just happened to me. $36.00 at AutoZone.


Note: Sometimes a stuck open EGR valve or a bad temp sensor can cause the same thing, but mostly the MAP that does that.

[Usendyduexy]

It's your MAP sensor. Same thing just happened to me. $36.00 at AutoZone.


Note: Sometimes a stuck open EGR valve or a bad temp sensor can cause the same thing, but mostly the MAP that does that.

id call map sensor too. also if your truck has a tps (throttle position sensor) that could cause it

[MondayBlues]

After reading the thread title, I thought this was a sexual question.

[KitRittyTug]

I honestly would have never of really bothered with this, and my Haynes Manual didn't say anything about it either,

But my Step-dad insisted that it was the dizzy cap. So, he ended up buying plugs, wires, dizzy cap and rotor for me.
I thanked him, installed it, and I have gone 15 miles without a single complaint from the vehicle.




I remember when my MAP Sensor was giving me trouble. The vacuum line fell off, and it was a bit jerky, but this jerky that I have been dealing with was way more then what the MAP sensor was giving me. As well with that MAP error, when I started up, I would get a nice cloud of black unburnt fuel with the MAP sensor.
That error also gave me an Engine Check light, but this issue didn't give me anything!




Guess it was all just a miss firing issue. Nice that it was that, and being easy. I was about to really tear into the thing to figure out what was going on.
I also think that I was running on only 5 cylinders. One of the wires on the dizzy just fell off as I went to pull it off, and that one plug was way cleaner / newer looking then the rest. Start up is much smoother and faster now as well.