so against my better judgement I paid someone else to put the plugs in my car. I specifically asked the guy to gap them at .035" and he said he put them at .033 because it was better. Sounds good to me I didn't argue.

Get in the car, grab the bottle and it detonates. Put it on the dyno and it's rich but still detonating. 109 octane and still detonating. Sounds like the f-ing motor is going to come apart, no joke.

Fine whatever, I'll sack up and tune the car. Well some **** happened and I was low on cash for awhile so I didn't have time to get the car tuned so I pulled the bottle out of the car and left it in the house. No bottle. Running the car on the motor though feels like a damn slouch. Won't even turn the tire over in 1st when it used to blow them off thruogh 2nd.

So I decide to be adventurous and pull a plug and check the gap. It slide right to .040" and would have kept going but I just stopped because it wasn't where it was supposed to be.

So I've had people tell me that the car will run fine with a plug gapped at .040" which I'm skeptical about and I've had people I trust (on more than one occasion) tell me the gap has to be spot on. I don't even know what all the plugs are gapped at... I only checked the one but I figure they're all wrong.

Is it JUST the plugs, or could it still need to be tuned? Regardless I'm pissed I spent 140 dollars on race gas and dyno time and it turns out to be the plugs are f-d up.. but should I try to spray on it again with 91 with the plugs gapped right or should I have someone pull a bunch of timing regardless?

 

.040 isn't that wide. My guess is the tune.

 

they're wider than that, I just stopped sliding at .040

 

What plug are you using...???

 

I would do a compression test and leak down before you do anything. Could have hurt the motor.

And like mentioned above...what plug are you using? What heat range?

 

its not the plugs. That 109 you added would trump any gap differences from a .033 to a .045 by a HUUGE margin as far as detonation goes. Your tune must be WAY out of whack or you have some other underlying condition or failure. Failure may be mechanical or a sensor.

 

NGK-TR6's, the same plugs I've used in all 4 other nitrous cars I've owned.

Ugh that involves driving alllll the way to my friends shop to borrow his leakdown tester, pulling all the plugs etc. The motor holds good oil pressure, doesn't sound too fucked up just makes a little noise before it's warm. Look above for the plug info.

This isn't at all what I wanted to hear... but I guess it's good I'm hearing it from people who have no intentions of telling me **** just so I spend money with them. Guess I'll put new plugs in it and go have the ****** tuned.


Thanks for all the help guys.

 

Not the plugs, and the gas should have took any knock away. Problem sounds like it could be mechanical, or your tune is wayyyyyy of. The guy didnt put in the wrong plugs did he? Stupid qiestion but figured Id ask anyway.
Regardless, get some new plugs, gap em right and install them yourself so you know they are done right.

 

not to be rude but you pulled a plug had the plug in your hand, and a set of feeler gauges ran it past 40 when it was said to be 33 and did not proceed to check the gap, put the plug back in the car, which sounds like the motor is about to come apart, and then to top it off you have a friend who all you have to do is drive over to his shop and do a compression test, but for some reason that is to hard? This is your car you need to get after it and make sure that it gets taken care of.

oh yeah and try this go to all of your spark plugs and twist and push the wires onto the plugs harder there is a good chance you have a loose plug wire that will drive fine under normal driving but will give you problems at higher loads. good luck

 

Ok....I agree mostly with posts above, yes, all of them.
However, I also think that the jackass gapping the plugs and your wallet should get his happy sack kicked. TR-6 plugs dont function well beyond .005 over/under their preset gap of .035". IF, jackass gapped your plugs to say .050 or more that could definately be an issue. Also, I agree if the mustang raping you couldnt gap the plugs correctly he probably doesn't know there are two clicks on coil/one click on plugs for the wires to be properly installed and most likely left the #6 and 8 cylinders not fully connected.

And ditto on rmitchells first paragraph.

 

 

Did you spray before the new plugs? Any issues then?
If not, did you had an aggressive tune prior? If yes, you should have reduced the timing for the nitrous.
Not to pile on, but nobody changes my plugs but me, albeit I don't have a F-body.

 

I'd definitely check / swap all your plugs (yourself). I never trust anyone to do mine because most people don't understand the nitrous factor. Try to get access to a data logger and see exactly what kind of tune your running (spark / WOT AFR). I can't imagine it detonating with fuel of that octane.

 

No, I've had a problem before on stock plugs and spray (in other words I blew out 2 head gaskets and bent a few rods) so I sprayed after the new plugs.

The thing I don't get is that the tune is stock and seemingly spot on. I wish I could figure out how to get the graph onto my computer so I could post it.

 

Car only sounds like it's going to come apart on the bottle. It makes a little noise cold but then everything goes away warm.

I put the plug back because I wanted the shop to fix it and they could see that one of their techs is ******* up. Plus I didn't pay someone money just to fix it 3 days later yanno?

 

Wow that's actually very specific... I'll go check that out in the morning about the wires when the car isn't hot as ****.

Thanks everyone again!