crAzy95z28

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Ok well car ran fine for years till now. I have a new motor in it. Has at least 15-20k miles on it. if not less. OK heres what happen. I live in Sugar land and drove my car to Lake livingston. About 100 miles one way. Well i filled up before i left. Got there with no problems. I drive around 85-90mph the whole way there (thats how i drive). Anwyays on the way back drive was good. I got on it a few times on the way back to around 120 or so. Well i drop my friend off and as im pulling onto my street, my car starts to rumble harder when giving it gas. I figured o great one of my rollerrockers backed off.


Well go to check that out and all are great. Have not checked the driver side cause usually the passenger side is what goes. I checked all my wires and all seems well. I also have ties to pull the wires closer from the header so they dont burn.

I do have a MSD blaster coil, MSD 6AL box, DynaSpark, NGK6's and 8.5 mm wires i beleive all from MSD, cept the optispark. I cleaned my MAF sensor.

Well after checking all of this it still runs the same. More throttle i give the more it rumbles like its timing is off or something. I also have a MSD timing retard system for my nitrous which is always set at 15.


Any ideas? Im thinking it could be the gas, but wouldnt the gas start earyl instead of late. 200 miles after?

crAzy95z28

Also the stumble is all through out the RPMS. Doesnt get worse or less. Stays the same all the way through.


It sounds like a burnt plug wire but i looked and found nothing. Could one of my plugs gone bad even though i replace them about 3 months ago?

Well went to drive it WOT and i have lots of HP missing. Do you think a plug could ov backed out? Cause i do hear some weird noise comming from passenger side kinda like a spark not sure? But at normal idle is runs great its just when i start pressing the gas is starts losing HP and stumbles.

DAVE00

Sounds like the Opti or ICM, check both. Did you put a new opti on it when you did the new motor and what brand did you go with?

crAzy95z28

i have a Dynaspark. Much better than the MSD and the reg one. Cost me 600$ when they 1st came out. So its not the opti. Now the icm (ignition control module?) im guessing. If im thinking what i think it is then its the MSD blaster coil that may have went out. Ill have to change that out back to stock to see whats up.


But 1st im thinking it could be plugs. I am using NGK-TR6's and i was running a constant 90mph for an hour at 3,500rpms. So one could have backed out or fouled cause of the vibrations. It does get pretty vibraty in high rpms. Plus its a 3200 stall biult A4 with 3.73 gears.

DAVE00

Don't let the Dynaspark fool you as it can still fail as it is still susceptible to heat and water being mounted in the same location as the stock opti. However, I agree and would start with the basics remove your ICM and coil and have them checked at your local parts store. As to the spark plugs that could be possible but not likely as guys road racing with more vibrations for longer than that don't see them back out unless you didn't torque them down properly.

crAzy95z28

the dynaspark is sealed so no water can enter or moisture. Plus its heat protected. Damn thing better be water sealed for coughing at 600$.


There may be a burnt wire i may have missed..The wierd thing is that it doesnt lose more hp the more throttle given. Its all the same throughout the band. Has me stumped. You think bad gas would cause this>?

DAVE00

Def could be bad gas but I would suspect more it's the ICM or Coil. Fill her up somewhere else and see how she runs.

mrmint69

I heard of a couple of people driving longer distances and at higher speed and have issues once they get to there destination. Usually its after a day long drive but if you were going from 85 to 120 for over an hour it might have over heated something. My friend drove from Phoenix to Spokane WA. in 2 days and then sold his car because it ran like crap and he never figured out why.

crAzy95z28

Hmmm i went ahead and put 20$ worth of 93 in and im letting it run through and after about 20 min of running it seems to of lighten up a bit on the stumbling.

Im hoping its the gas...

mrmint69

Are you running premium all the time? I always do.

crAzy95z28

I found the prob. Somo how i must of overcheck the plug wire. I saw some arcing on the oil dipstick tube and fair enough i replaced that and solved all my problems.

So it was a burnt plug.

DAVE00

Great news and glad you figured it out.

MTBSully

newb question, what is arcing and how did you find it?

DAVE00

Arcing is when you have exposed core of the wire and it's arcing electricity to the nearest ground and that is usually the headers as they burn thru the insulation most of the time. Same thing happens when you have a cut electrical cord in your house and you see sparks when you plug it in. You find it by the ticking noise made and if the light is low you will see flashes from the sparking.