bucking/missfiring problems with 2001 4.3
 

ok, so i have this problem with my 2001 zr2 2door with the 4.3 regarding a bucking (as if it were starving for fuel or miss firing) off the line until i hit about 30 miles an hour then the problem goes away. also i have a power loss problem on long trips when my engine wont go over 2000 rpms if im not going fast enough or down a hill on the highway. I feel that i should mention that i had a terrible habit of running the truck on no gas and often times i would let it run out trying to stretch my gas to the next fill up to try and save pennies (i now see the error of my ways).

OK check out my thread called "Found my problem!!!" and read it towards the end about the ground splice pack called sp423, it sounds exactly like the problem i had until i finally got sick of it and pulled out the wiring schematic and started making sense of chevrolet's circuit designs, i'm still trying to figure out why they put the egr and the intake air temp. sensor grounds all the way on the rear crossmember where all the water and road salt accumulate, WTF???

honestly i dont doubt it, ive had some serious wiring problems with this truck, not that wiring is fun in the first place, but the guys in jersey who wired my particular truck must have nursed their thumbs with their assholes cuz ive had nothing but headaches.

what do you mean the guys who wired your truck?? did they put a new harness in your truck? or pulled the ol' duct tape and wire nut trick......

haha, no im just bustin the chops of the guys at GM who put it together in the first place. I've had many qualified techs look at my truck for its ailments. they all comment on how screwy the truck is wired (granted we never really had the right schematic for my truck, it was always a few years later or earlier). i dont see what makes it much different from any other GM as far as wiring goes, but im not nearly as knowledgeable as those guys are.

regardless of my feelings on my trucks wiring, im deffinatly going to check the thread you mentioned and go from there seeing as Ive had both grounding issues in the past

Yea cool, please post back what you find. The bolt that holds down sp423 was very rusted on mine and it's kinda hard to find but just study the pics i put up there.

good luck

so i brought my truck to the garage to have it looked at by a mechanic and to my supprise, i apparently have a busted motor mount and the thing lurches and twists every time i give it the beans (hence the bucking). im having the broken mount replaced, but my concern now is with the other one. what would the chances be of that mount breaking seeing as how it serves as the fulcrum when the engine revs and twists in the compartment?

Rifleman I have looked and looked for your post I am having same problem any help?

mross, yea i know i've heard that before...weird......but anyways if you click onto the search option then the ADVANCED SEARCH option in the search window then type "found my problem" in the search window with an author of RIFLEMAN 308, then it will take you right to it!!! you can pm me if you like.

kyle i would wipe down the good mount with a DRY rag really good and then inspect it with a bright light really close. The reason you should use a dry rag is it will leave any engine oil or road dirt etc. in the hairline cracks if they exist. If no cracks then check the rubber isolator in the mount and make sure it isn't ripped. you can check this by jacking the motor up on the side of which you are checking and watch the rubber stretch a LITTLE and the look for rips, if no rips and no cracks, then keep on truckin'!!!!!