91 S10 Jerks when you let off the gas.

[Wilbo]

Hello, did a search didn't seem to find anything on this.

I've got a 91 2.8L S10 . It starts fine, engine runs fine and if you rev it up the motor runs smooth no missing etc.

Heres the problem, at lower speeds if you let off the gas suddenly it starts to jerking. Sorta like you see on tv when people aren't used to using a clutch and it jerks around. It also does this when you first start to accelerate unless you give it a bit more gas than you should. It used to just slow down when I let off the gas now it just jerks around. Now it shifts fine, doesn't make any noises. No grinding etc. Its a 5 speed manual transmission.

Another thing that might or not be related I noticed is if its in neutral , when you give it barely a little gas it almost acts like its gonna die but then picks up. Nort sure if this is normal as I don't really know much about trucks.

I've change spark plugs, rotor, distributor cap, had to replace the Ignition control module last week and plug wires. The check engine lights goes on and off and has been doing this when my brother owned the thing so give or take 7 years of it randomly coming on.

The problem seems to be getting worse any ideals would be appreciated thanks.

[jackass#1]

i would get the codes read, but im pretty sure it a egr problem. needs cleaned or just replaced. auto zone will read your codes for free. when you find the codes come back here and give them to us and we will be able to help you out further.

[OverBoardProject]

Welcome to Automotive Forums Wilbo

If it doesn't have any codes get the fuel pressure measured. It sounds to me like it might be flooding it's self.

[Wilbo]

Thank you , I'll check into that.

[blackwidow98]

check the o2 sensor too

[Wilbo]

Thanks for the tip but I checked the egr valve like jackass#1 suggested and its all but eliminated the problem. Thanks for the help folks.

[jackass#1]

were you able to get the codes read? im glad to help, but if the problem comes back check fuel pressure. i remember when i had a similar problem it was both egr and weak fuel pump.

[hakogen]

hey guys, been a while...

just wanted to give you guys a heads up... auto zone only tests obd2 stuff... 91 is a bit before that.

[Southern Comfort]

You may want to change out the TPS (throttle position sensor) that will cause that sort of problem as well as the weak fuel pump and a bad egr as well as a bad fuel pump regulator. Have you replace the fuel filter lately. That could be part of your problem too. Sorry to say, there are so many things that can cause that problem. Just trying to give you an idea what to check.
Thanks
SC

[Techyon]

If that truck is a longbed it might have a carrier bearing on the driveshaft.
When those fail they can cause a shaking effect to the vehicle on decelleration.