This is a strange problem (maybe not even a problem but) When I'm driving my '95 T/A around just cruising at 30, 35, 50, 55 whatever speed...the car seems to have a miss to it. However, when I get on it, there's no loss of power whatsoever and runs great....just when cruising. I'm positive the plugs/wires are all fine and I've got new gaskets on the whole exhaust system but I can't figure out why it seems to have a miss when holding at a set speed. I only really drive the car on the weekends, (drive a Ford Expedition during the week) and since it has the Hotcam maybe its just the cam and I'm not used to driving it that much. Is this normal? Here are my mods BTW

'95 T/A M6 (used to be an A4)
Stock thermostat
Stock injectors
No Air pump system
Moroso cold air induction kit
AS&M 52 mm throttle body
No CAT (straight pipe)
TPIS 1 3/4 shortie headers
LT4 knock module
Ported/polished MAF (removed screen)
Flowmaster Muffler
LT4 HotCam
Ported LT1 heads
2.00/1.56 Manley race flow valves
Crower Springs, Chromemoly locks and retainers Good to .580 lift
Comp Cams screw in studs and guide plates
1.6 GM Rocker Rollers
Flow as follows:

.100 71/62
.200 133/112
.300 187/157
.400 219/185
.500 248/192
.550 258.5/193.5

and custom tuned by Ion Soltan.

Thanks for any help!

 

my plugs went at less than 50k miles, they were factory. I only noticed the miss cruising at high speed or accelerating.

Wire trouble has given me cruising miss with no noticeable miss at WOT. I had to check them very carefully, but if you dont have headers, then its unlikely to be a wire prob

 

i think i have this same problem except my miss is VERY noticable unless i'm above about 2300rpm. i just replaced all my ignition stuff except the coil itself (it worked fine before the cam change). i know i have exhaust leaks from the header/ypipe install, but that can't cause a miss can it? also, my miss doesn't seem to happen too bad when the car is cold....seems wierd to me. is yours like this?

 

TTT, I have this problem as well and I'd like to know what causes it. I have all brand new opti, coil, plugs wires, msd digital 6. It still does it. When I go WOT it just flies, but under 2000 rpm light throttle cruise there is a small buck/hesitation. MAF maybe???

 

That sounds hardcore like a plug wire. You sure there is no arcing going on, or that the wires arent touching anything (eg. hot header pipe)?

 

I'll bet it doesnt do it when your first start it does it? Its your O2 sensors, replace them and i bet it goes away. I had the same problem. The O2's arent used in open loop, or at WOT, thats why it goes away when you floor it or first start it up.

 

Brand new o2's an extensions... they were switching pretty slow before. I think it may be the MAF, I just have one of those hunches... anybody have experience with it???

 

You have an aftermarket cam or is it stock? It could be in your tuning, is it a definate miss or is it a little bit of cam surge?

 

It may be cam surge, I have a blower cam sort of on the large side. It's on a 115 lsa though... I don't think it's surging though. Whenever I feel a little buck I hear the exhaust pop very slightly. It's something only a trained ear or the owner of the vehicle can hear... That's why I am thinking some sort of sensor because my ignition system is all brand new good stuff.

 

try cleaning out your fuel filter... a fuel pump doesn't run all the time except at full throttle, so when you are cruising it pulses...i see that happen all the time in other cars and that usually fixes the problem....take the filter off and spray some brake cleaner in backwards... (be an arrow on it) and see how dirty the stuff comes out

 

could be your MAF i started having that problem and it got worse and worse tured out my mass air sensor went bad