Engine jerks at any speed

[DieselDaze]

started doing it only once in a while but now all the time when engine slightly warms up.. started shortly after I installed a 5" down pipe back, full egr delete and lbz mouthpiece..

truck has 194k on it, only thing I've ever done is replace water pump and #2,7 ice pick..

truck feels like your foot slipped of pedal then rammed it again, doing it more times than not.. check engine light came on for a while but is now off again, don't have a proper scanner to check for codes and autozone scanners is a joke and no help.. tempted to take it in but would rather do it myself..

any help would be appreciated..... has no tuner...

 

[Chevy1925]

check your ice pick job. might need to be redone

 

[DieselDaze]

I'll try it, but when it acted up before the ice pick fix it had no power and was in limp mode as though the fuel filter was clogged.. now it just jerks..

BTW just replaced the fuel filter yesterday to see if that was it, still doing it..

 

[MD_Max]

I have similar problems every now and then, i have an accelerator pedal code on mine. Already replaced it and it came back, not sure what's going on. Get the codes checked then we can help out
.

 

[ikeG]

Are you sure the jerk isn't in the drivers seat?

Is it a bad fuel pressure regulator surge or worse like a lope tune feel?

 

[DieselDaze]

never had a tune so wouldn't know, never felt what a fpr surge feels like, so....
I'm leaning toward a tps problem though I can't be for sure but I also failed to mention last week as I left the gas station my accelerater was gone, I could press the pedal and nothing happened, I had to floor it all the way down to limp 5mph to work which was a block away... after work pedal was there and had no problems making the 20mile trek home...

 

[DieselDaze]

no codes are thrown, cleared engine light and the problem seemed to go away only temporarily....problem continues and I'm stumped....

 

[Chevy1925]

Check engine light means you have codes. We need them so you need to get a good scanner like a tech2

 

[DieselDaze]

I only have a cheap HF obdII/can, it identifies with truck or at least appears to.. works on my jeep just fine... guess i'll have to take it in

 

[Chad006]

when you say you've never had a tune you mean a lope tune right? Dumb question but you do have it tuned for the egr delete?

 

[DieselDaze]

no sir perfect question, that's my point I never did anything to the truck after installing delete kit, mouthpiece, and 5" straight exhaust... truck acted up a few days later on a 550 mile road trip... didn't know if it was a fluke or directly related... tried to have truck 'reflashed' but the guy that did them wasn't in the shop when I had my new tires installed...

 

[DieselDaze]

btw the scanner I bought shows 'live stats' while the truck is driving is there anything in particular I should look for that could be out of spec?

also fwiw I unplugged the egr wires over 5 yrs ago to see if it would trip the engine light and it never did... after the delete and other mods is another story

 

[catman3126]

check the grounds on the pass side of the block down low by the oil pan, I had one doing a similar issue. if the wire is broke but making contact and causing the jerk.

 

[DieselDaze]

thanks catman will do...

drove 100 mile round trip today with no problems, however the engine light came on again and this time threw two codes..

PO698
PO341

only thing I did to it last night was jiggle and disconnect the tps wires at the pedal, surely this didn't help it run better today.....

really no sure why it ran so good today I've done nothing to fix it...

 

[Chevy1925]

you need to start looking at the typical rub spots for an LLY (by the FICM and alternator are common). your codes point to a cam sensor issue and throttle sensor issue. i bet you have some wires getting rubbed through.

 

[Chad006]

If it's not wiring could be Reluctor wheel issue possibly?

 

[Chevy1925]

If it's not wiring could be Reluctor wheel issue possibly?

thats for the crank sensor

 

[DieselDaze]

ahh......checked wire rub last night moved wires around etc wonder if that helped although I didn't see any exposed or visibly damaged circuits.....

hope this cps is just wires and not the reluctor, just read what's involved in replacing it and soundsee like something out of a Stephen King novel....

now I need to figure where the cps is so I can take it off and probe around at the reluctor wheel

 

[DieselDaze]

thats for the crank sensor

okay good to hear, but I swear when I looked up the 341 the reluctor came up.....

 

[DieselDaze]

update: to confirm po341 does mention crank sensor as well as timing belt/chain and the reluctor wheel as causes for code..

here's the deal, earlier i sprayed all the connections on drivers side valve cover with MAF sensor spray as it was the only thing i had here that evaporates quick (I know) went to go pay a bill 2 miles from home and the truck jerked the whole way, auto parts locate at same strip mall so bought some electronic cleaner and sprayed wires in parking lot.... started truck, engine light went off and truck drove like a champ back home.... fluke?? Idk but I must investigate further but I have a feeling there is something up electronically... as I failed to mention as I didn't think it was related to my problem but a while back my a/c would only operate on the defrost, vents and other controls would not work... then later that day started my truck and the vents worked!!!

stupid question: I want to clean the main harness connectors do they unplug?? I removed the clip but it appears there aren't any tabs to squeeze to get them off and I donto want to force them if there's an actual solution...

still intend to take off cps and check reluctor wheel as that has me worried, but I'll remain optimistic this is an easy electrical clean..