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OT: LT1 and NOS

I just helped a good friend of mine install a 150 shot of NOS on his '96 Z28 over the weekend. What a major pain in the ass, but anyway, I have a question. We have the kit all installed beautifully, you can't see anything under the hood, it is completely hidden. We changed the plugs(it took a long time, and lots of blood sweat & tears, damn chevy) for some colder plugs with a .37 gap. Now the car runs really rough at low rpms. It feels to me that it is running on 7 cylinders below 2500 rpms. We checked all of the plugs, wires, MAF, and everything else obvious, but we can't figure out what is causing the problem. Also, it didn't start the problem right away, it started after we tested out the NOS for the first time. Also, for a 150 shot it sure didn't feel too strong. I've ridden in mustangs with a 150 shot and it really threw you in the seat when the button was hit. Anyway, does anyone have any ideas what could be the problem? Any help would be appreciated, thanks! BTW, the car runs fine at cruising speeds also, its just when he slows it down and drives normally from a stop. Erik D. '94 white lightning

Reply to
Erik D.
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Really sounds like a bad plug/wire. Have you re-checked all the plus and wires post-install or post "foot to the floor with the N20? I know the LT1's SUCK to change plugs but I bet that's the problem.

Mike

Reply to
Mike

Yeah, I really really thought it was just going to be a loose wire, but my friend(the owner) checked them all out today and he said he made sure they were all tight and none were melted or anything. You think a plug could have gone bad already??? I sure hope not, those things were a bitch to change(i'll be cursing GM for a long long time). Thanks for the response Mike! Erik D. '94 white lightning

Reply to
Erik D.

My first guess would be to a plug wire as well. I used to have one of those LT1s. Perhaps the combination of the colder plug with that gap has brought out a problem in one of the wires that wasn't noticable before. Symptoms to look out for on these:

  1. Does it pop out the exhaust at high rpms?
  2. Does the catalytic converter seem to work harder than it normally does (smell)?

Note that a bad plug wire can cause your friend's coil to go bad as well. This happened to me more than once. Generally I would change wires along with plugs. Expensive, but worth it.

Reply to
Victor DiMichina

Thanks Vic! He has Kooks headers and an arizona speed Y-pipe without cats, so the cats aren't working at all, lol. I didn't notice any popping sounds at high rpm's either. Hopefully it is just a wire, cause I really don't feel like fooling with the plugs, lol. Thanks again! Erik D. '94 white lightning

Reply to
Erik D.

Have you tried the last night plug wire check? Wait till dark and with the car running raise the hood and look for arc. I have found problems this way before with many "there good I checked" wires before. Of course if you have a nice dark place to do it you won't have to wait for night.

MadDAWG

Reply to
MadDAWG

You can goto

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They specialize in LT1 and LS1 proformance. And if you want to see pictures and a short .wmv of my car and a couple of my friends on the dyno Saturday at Thunder go here...
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Reply to
WindsorFox[SS]

Thanks man, he got all of the parts from thunder racing. We figured out the problem, turns out the #7 plug was bad. He should be getting a new one tomorrow and I think we are going to No Problem to test it out. Thanks for all the responses :) Erik D. '94 white lightning

Reply to
Erik D.

Yeah they are good people. They gave away prizes and had free food on Saturday. Man I was hoping for that nitrous kit! I know James from AOL, maybe he'll make me a deal on a Nitrous Express kit :-D

Reply to
WindsorFox[SS]

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