97 gmc 4.3L standard 4x4 and hesitates while driving

[molsongolden2006]

Went down to my hunting camp on friday nite everything was fine....but on the way up while i was driving the truck would give me little jerks....just to say....its hesitating alote at a certain speed...like around 60km it jerks alote

i had a brand new clutch put in the week before(it was due)
any ideas....this is what we can eliminate 1.brand new fuel pump
2.new ignition module
3.ignition coil
4.feul pump relay
5.spark plug and wire last year
now the only thing left would be the coil pack??
it was very humide this weekend im baffled??? can anyone help me out

[Trumanjr]

Looks like we have the same vehicle and the same problems. It also seems we have change out the same parts with no success. I have been looking into the Mass airflow sensor. I can not find much information on the sensor though. I was watching one of the car repair show on TV when they mentioned the cleaning the sensor. My ears really perked up when the guys on the show mentioned that if the sensor was dirty it may cause hesitation or possibly misfire. Have you heard anything about this?

[molsongolden2006]

Well for me i was thinking it was the EGR valve and cant come up
with anything else....im going to run a scan tonite...even tho the engine
lite isnt on...and let you know

Mike

[MyTOY]

mine would miss like that only in OD cause of the load I guess, changed my wires which was the only tune up part I couldnt get to (afford) & it is gone.
I had already replaced cap/rotor. It seems this is where alot of folks misfiring
comes from. I would check it out

[MyTOY]

also cleaned the MAF jus cause it was easy. this was after fixing the miss

[molsongolden2006]

How is your truck running now? im going to run the test sometime this morning....havent had time really busy with new baby(7mths) as soon as i get results i will let you know...

[snowman_106]

I have the exact same problem with my 01'. My fuel pump just went out a few months ago and the problem has not stopped. Please let me know what you have done to solve this problem. Also I have noticed a significant drop in MPG. I used to be able to get 200 mi by the time the needle hit 1/2 tank. now it is almost 3/4 by the time it hits 230 mi. I haven't actually figure the mpg recently just have noticed the fuel gauge drops faster.

[molsongolden2006]

Well i FINALLY figured it out....it was the cap and rotor it was all coroded
inside as soon as i changed that everything worked just fine....i put it
on the scope just to be safe and all the values are 100%

now driving home from works last nite and now new problem....my temp
gauge goes up then down...then back up.....im thinking its the themostate
no heat at all so will change that tonite......