I have a 04 comp g gtp and when i first bought the car it would do 138 mph no problem. I went to zzp and had them tune the car about 2 months after that the car wouldnt go over 120 and it felt like a misfire but never threw a code now on hot days it will do the same thing at about 86 and it will kinda jerk back and forth and not go any faster then 86 somtimes it will do it a 75 mph but it only will do it if i punch the gas the car wont throw any codes i have replaced the fuel filter spark plugs and wires and the air filter the cat was cut off. i replaced all the vacume lines thinking i had a air leak but I have a boost gauge its putting out the same as it always has. the car has 180,000 miles on it but all highway miles abd its well taking care off. I am out of ideas any clues?
04 Comp G prob
- Thread starter metal3753
- Start date
Fivefingerdeathpunch
New member
How long did it take to reach 138mph??
Like 2 years???????????????????????????
There is no reason to ever pass 110-120mph, the stock transmission is not built for that, shifting into 4th gear at such speeds is just asking the trans to implode.
If the car is still bucking and acting like it doesnt want to go, I'd say you still have a misfire going on. What spark plugs did you use??
Do you have a SES for not having a cat converter now?? Because that can cause issue's aswell.
Like 2 years???????????????????????????
There is no reason to ever pass 110-120mph, the stock transmission is not built for that, shifting into 4th gear at such speeds is just asking the trans to implode.
If the car is still bucking and acting like it doesnt want to go, I'd say you still have a misfire going on. What spark plugs did you use??
Do you have a SES for not having a cat converter now?? Because that can cause issue's aswell.
Fivefingerdeathpunch
New member
But your complaint isnt about trying to reach speeds that double the posted limit.
He can't go WOT past 80-90 mph because of the surging/bucking from what I gather.
Sounds ignition related to me, because if it was the transmission he'd be seeing more problems even at lower speeds during normal driving.
Timing
New member
His issue is the EXACT thing my car is doing and started happening shortly after removing torque managment from the car (his zzp tune did this also)
If i wot all the way to 116 the car starts surging and cant shift until i let off gas to allow it to. Happens at 80 too when im cruzing and i try to go wot from 4th to 3rd and tries to shift up to 4th and cant but doesnt happen in any other gear.
Timing
New member
I was thinking that when it happens the engine is under huge load and the converter is locked correct? So maby there is an underlying issue. I have done everything to this car besides the coils, icm, upstream o2, and fuel pump. And any of these i guess could cause the issue cus with the tc locked up and the engine under such huge load i could be getting gimped from one of these causing a misfire and a a lack of shift there of. Ima go for a ride and scan to see if im getting any slight misfires and see what everything else is doing.
Timing
New member
no if its a slight misfire it wont. You need something to scan the car to watch the misfires in every cylinder. I would try basic maintenance stuff like fuel filter, plugs, wires, pcv, seafoam threw side T vacuum, seafoam in the gas, clean tb, maf ect
Im thinking that the cyl 5 is only misfiring cus i heard people having problems with the front cyl not getting cleaned when seafoaming through the brake booster hose, so ima grab a can and run it in the T i was talking about under the s/c snout and see if i notice a difference, then ill change my plugs again concidering they are 1$ each and swap around coils injectors and see if it follows.
Im thinking that the cyl 5 is only misfiring cus i heard people having problems with the front cyl not getting cleaned when seafoaming through the brake booster hose, so ima grab a can and run it in the T i was talking about under the s/c snout and see if i notice a difference, then ill change my plugs again concidering they are 1$ each and swap around coils injectors and see if it follows.
How do i seafoam through the t? and i just replaced the wires, plugs, maf, air filter and fuel filter about a month ago and nothing changed also i run the BG injector cleaner through my fuel rail and the tb cleaner through the tb often and have ran the seafoam before oil change. It only seemed to start doing this a few weeks after i took it to zzp and had them tune it could somthing in the tune be messin it up?