this car is starting to get to me

[98svtconvert]

this has been a problem that comes and goes. at high rpm's the car lags and sounds like it is missing. i went to the track this passed friday and that is when i noticed it was back. origionally i thought it was the coil packs so as you can see in my sig. they are gone. even though they weren't the probmlem this time they aren't going back on because the keep messing up. any way i was having to shift at 5900 because any higher and the car started to die out. it almost feels like the rev limiter is trying to kick on. dyno'ed it about 3 weaks ago for the same problem thinking that it was leaning out at the top end. on the first dyno pull the a/f was below 10. so we ran it 3 more times and it was perfect on all three. didn't hear the sputtering at all on the dyno. took it out after that and it didn't do it on the road either. now i go to the track and it starts doing it again. any idea's. this is really starting to piss me off. i have to drive about 2.5 hours to get to the track so it sucks to get there and only do 4 pass's and have to stop because i didn't want to break it. any info would be great. thanks.

 

[Tat98Cobra]

this has been a problem that comes and goes. at high rpm's the car lags and sounds like it is missing. i went to the track this passed friday and that is when i noticed it was back. origionally i thought it was the coil packs so as you can see in my sig. they are gone. even though they weren't the probmlem this time they aren't going back on because the keep messing up. any way i was having to shift at 5900 because any higher and the car started to die out. it almost feels like the rev limiter is trying to kick on. dyno'ed it about 3 weaks ago for the same problem thinking that it was leaning out at the top end. on the first dyno pull the a/f was below 10. so we ran it 3 more times and it was perfect on all three. didn't hear the sputtering at all on the dyno. took it out after that and it didn't do it on the road either. now i go to the track and it starts doing it again. any idea's. this is really starting to piss me off. i have to drive about 2.5 hours to get to the track so it sucks to get there and only do 4 pass's and have to stop because i didn't want to break it. any info would be great. thanks.

seems ignition related to me - almost sounds like you're experiencing spark blowout. COntrary to popular belief, it can and does happen to N/A setups too. Something is weak in your ignition system. COuld be bad wires, or plugs. Hopefully you went back to stock coil packs? They are in fact the best. what type wires are you running with? plugs?

peace

 

[98svtconvert]

i have put my ignition back to stock to try and solve this but it hasn't worked. the car only has 29000 miles on it. also the idle will act strange some times. it will rise to about 1300 and just stay there for a while and then go back to normal. i don't mean the slow return to idle. i have been sitting in the drive way after coming home from work and it will just go up to 1300. it happens while at stop lights as well. could some thing be clogged or dirty. i keep the engine bay very clean but i haven't removed anything to clean parts except for the air filter.

 

[CNEPACE]

I went through the same problems and swapped everything and still no luck. I finally took some advice and swapped out the IMRC control module. My car would sometime feel like its lacking power after 5000rpm. It almost felt like I was getting hit by waves of headwind and the car didnt want to wind out. My imrc's were not opening all the way and sometime they would. Save yourself the trouble and just replace them!

 

[98svtconvert]

that is kind of what i was thinking. how much are they.

 

[COBRA_SVT_VERT]

Fuel Filter

If you haven't already replaced this, do it now.

 

[mustangrmyk]

I second the fuel filter before you spend more money.