Weird Stumble
Ok guys looking for some input. My car has a TVS with 3.0" upper and 4lb lower, lethal return style, ID 1000's, Accufab, JLT RAI, full exhaust and I'm running 93 + Torco. So I had the car tuned this week and on the dyno she pulls like a freight train all the way to the top. Once the tuner hit the streets to dial it in we started to see a weird "hiccup". It started out doing it way down low at ~1200rpm like when you would pull away from a red light you would feel it. Then as the car heated up the "hiccup" would get more pronounced in other gears and rpm ranges. Most commonly at 2000-3000 rpms in 2nd or 3rd you could really feel it "breaking up". The weird part is even after 5 hours of driving and data logging we still couldn't nail down what was causing it. It doesn't do it at all under WOT. So last night I switched out the BR7EF's to TR-6's, gapped at .028, and that really helped. It took out the stumbled that was happening down low when first pulling away from stop signs and red lights. The "hiccup" between 2000-3000 is still there but much less pronounced. The "hiccup" only happens in 2nd and 3rd gear which is a little puzzling. I am still running stock coil packs and they have almost 87,000 miles on them so I'm not sure if I should just replace those to rule them out or not. I hope this makes sense to you guys. I'm no expert on cars and some of my terminology may not be exactly right. Thanks for any help or advice that you can share.
Ok guys looking for some input. My car has a TVS with 3.0" upper and 4lb lower, lethal return style, ID 1000's, Accufab, JLT RAI, full exhaust and I'm running 93 + Torco. So I had the car tuned this week and on the dyno she pulls like a freight train all the way to the top. Once the tuner hit the streets to dial it in we started to see a weird "hiccup". It started out doing it way down low at ~1200rpm like when you would pull away from a red light you would feel it. Then as the car heated up the "hiccup" would get more pronounced in other gears and rpm ranges. Most commonly at 2000-3000 rpms in 2nd or 3rd you could really feel it "breaking up". The weird part is even after 5 hours of driving and data logging we still couldn't nail down what was causing it. It doesn't do it at all under WOT. So last night I switched out the BR7EF's to TR-6's, gapped at .028, and that really helped. It took out the stumbled that was happening down low when first pulling away from stop signs and red lights. The "hiccup" between 2000-3000 is still there but much less pronounced. The "hiccup" only happens in 2nd and 3rd gear which is a little puzzling. I am still running stock coil packs and they have almost 87,000 miles on them so I'm not sure if I should just replace those to rule them out or not. I hope this makes sense to you guys. I'm no expert on cars and some of my terminology may not be exactly right. Thanks for any help or advice that you can share.
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