A friend of mine has a 2000 ss with long tube headers, no cats, stock injectors, stock intake manifold, port matched heads and a MS4 cam. I went for a ride in the car today and I noticed it is hesitating in the low rpm range; he said it was running fine but just started this. First he noticed his temp gauge fluctuating so we changed the temp sensor, it did not help the miss but the gauge is stable now. The car shows no codes and it just started this on the way back from a drive to Vegas. I am thinking he damaged a plug wire or two with his headers; he is running stock autozone wires with ngk tr55 plugs. What could the problem be?

 

he could be having a coil starting to go out. An if the miss fire is not to server it will not through a code

 

You title says a miss. Your text says a hesitation. Two different things. Which is it?

 

Pretty stupid idea running stock 99-00 injectors with that setup.

 

Which wires does he have because that could make all the difference... if they are Duralast then they are probably okay but if they are Valuecraft... roll up a newspaper and twak him upside his head then tell him to replace them.

 

They are duralast wires, but they are really close to the headers. I recently burnt three of my duralast wires on my lt1; but my wires were not as close to my headers as his are. Yes he knows he needs new injectors and plans on buying some 42lb injectors along with a ls6 or fast intake. He just shipped out to GA for Army basic and officer training, so he will not be able to fix it any time soon. I think new wires, plugs, 42lb injectors, intake and a dyno tune will clear it up. I suggested he buy some ngk iridium plugs because my car seems to run a lot smoother with these plugs over autolite 106 and ngk tr55s and I noticed GM has a TSB on installing iridium plugs.

 

He should be running NGK TR6 plugs at .040" gap. Also go with MSD wires. They allow you to bend to the boot away from the header primary for clearance. May not fix the problem, but if you're going to replace the ignition parts, you might as well do it right.

If you suspect the wires arcing to the header, watch for an arc at night. LIGHTLY misting water in the area may help.

Did you also say the car is not tuned!?

 

sounds like he might need some header boots for the plug wires.

 

I've owned 6-7 LS1 cars, any I've NEVER had problems with the spark plug wires. I'd say that it's something else.. Probably tuning or the stock injectors or the overly-big cam isn't idled correctly.

 

You are most likely correct. He has a tune, but its only a mail order tune. Mail order tunes can be off, even on easy setups; my hotcam only car ran like crap with my first mail order tune. I would like to have seen how his spark plugs looked; I think some are fouled, ether from bad plug wires or the combo of insufficient supporting mods along with a possibly incorrect tune. We will find out what it is when he comes back from training in about 1yr; as it sets now my full bolt on lt1 hotcam car feels a bit faster. One other thing I noticed is on first start up his car had a slight knock sound that went away in a few minutes. I told him it was because the ls1 is all aluminum and sleeved we are hearing piston slap; I hope that is what it is because if its not he has a problem.