itSSlowZ28

iTrader: (5)

also posted on cz28.com

the car: 95 a4, performabuilt 4l60e, performabuilt 3200 stall convertor, new tr6's, new plug wires, new msd opti, msd coil all within the last 1000 miles. new o2's within the last 1500. also has lt headers with a bullet dumped off of the y-pipe, gears, elbow and cai

the problem: car has a bad vibration under a load, most noticeably around 40 mph once the convertor has locked up. at first i mistook it for a misfire and found a burnt plug wire which didn't fix the problem when replaced. also fix a few vacuum leaks. i call it a vibration but it is not consistent, sometimes it won't do it until you put it under more of a load and sometimes you can literally feel it stop and start. i know my way around my car pretty well and cannot figure this out. went to the track to gauge how bad it is and my mph is VERY low for what it has done before (95 compared to 102). it has thrown a code for each o2, but not at the same time. also threw an EVAP code and the idle is high but will return to normal after a second or 2 with a quick rev

i am at a loss. i'm sick of the thousands i've put into it hoping to fix this problem. i'm almost ready to take it to a shop and make it their problem

IronOutlaw

iTrader: (4)

Could be torque converter shutter. Put your foot on the brakes to unlock the converter and see if it still does it.

AdsoYo

iTrader: (1)

If it's throwing those codes at you, could be something in the PCM circuit. Maybe a crossed/damaged wire, bad ground, or the PCM itself.

itSSlowZ28

iTrader: (5)

the entire trans and tc have been replaced. it was doing it before i lost 3rd and 4th and is still doing it now
what in the hell would i do to check that? i'm open to pretty much any suggestions as to possible problems, but if that is the case i'll have a shop do it

ss.slp.ls1

iTrader: (36)

Might be a stupid question, but have you considered it being a bad trans mount or an unbalanced driveshaft?

AdsoYo

iTrader: (1)

To rule out the PCM you'd have to swap in another one, either a spare or a friends. For the wire circuit you could use a multimeter on the pigtails and grounds and/or painstakingly inspect the length of the wires in the harness.

itSSlowZ28

iTrader: (5)

i considered that, but the fact that you can physically feel it stop the vibration at times. it feels like a stumble, and the fact that it is so intermittent makes me lean towards something electrical

PNYKLR-TA

iTrader: (1)

I was thinking the same thing.

Or even motor mounts for that matter. . .

RamAir95TA

iTrader: (2)

Don't rule it out because you don't "feel" it's the cause. You never know.

PNYKLR-TA

iTrader: (1)

i agree, my tranny mount was going out and only somtimes did it feel like it was stumbling, other times it felt fine, and firm.

itSSlowZ28

iTrader: (5)

i've had a bad trans mount, it is nothing like what it felt like. it also does it sitting completely still at a redlight in drive, and the rpm's will pick up after a second and it smooths out completely. and something like that wouldn't kill my mph that bad i wouldn't think

ss.slp.ls1

iTrader: (36)

You know I had a similar problem recently and I found that my ENG SEN fuse was blown. But you'd be trowing codes if that fuse was blown.

itSSlowZ28

iTrader: (5)

update! just walked out to check my vacuum lines where the egr was deleted. happened to accidentally touch the #7 injector and the connector just popped free. plugged it in, double checked all the others and now the car runs smooth as ever with all the power its been missing

ss.slp.ls1

iTrader: (36)

Weird.

itSSlowZ28

iTrader: (5)

very, i realized its missing the metal clip on the #5 and #7 injectors that hold it in place. probably got lost by the mechanics that replaced a blown headgasket 2 years ago. anyone know if you can get just the clips somewhere? the car will be getting tuned soon so if not, i'll go ahead and order some slightly bigger injectors for the trip to tick/pcm4less