What plugs should I use???
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Teching In
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What plugs should I use??? Hey guys I just installed a set of LT headers and replaced the plugs but now I'm getting a pretty bad missfire. It's a P0300 code which means random misfire. The thing is, I installed brand new plugs with the header install. I used the NGK TR55 Platinum's. Is this too cold of a plug for a basically stock car? All I have done is the exhaust and K&N filter.
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And all my wires I made sure were placed a good distance from the headers. Last night I had my brother look down on one wire that was close to the header to see if it was arcing off and it wasn't. And if it was, you would see that in the dark right?
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Yeah I'm not sure when or if my opti has ever been replaced. I read about another guy having the same problems as me and it ended up just being a bad o2 sensor. And the funny thing is my driver side o2 sensor cracked and one wire was wanting to work it's way out and I've had to push it back in several times since I did my header install. But once I get that new o2 if it's still doing the same thing I'll check out the opti. But thanks for the advice. I'll let you know something prolly tomorrow.
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well i didnt do my headers a shop did them, but i had them install new plugs too. I got the car back and it idled fine but when i got on it about 2-3 grand the car sputtered and missed like hell. I thought it was the opti and so did the shop that did my headers. So i took the car home and went through and pulled every plug and come to find out they smashed two of the spark plug contacts to where there was no gap. so i bought regular plugs cause the ones i had them put in where the Bosh platnuim 4 and i heard those suck on a domestic. changed the plugs and the car ran great. CHeck the gap on them i think the stock gap is .050. when my opti went the car would miss and run rough at ible and back fire like a mother. did you put your car under a load when you looked for arcing of the wires? have someone put it in drive and hold the brake and check it again.
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Performance and Technical information on setting spark plug gaps.
Are plugs pre-gapped from the factory?
Yes and no. A spark plug part number might fit hundreds of engines, and although the factory will typically set gap to a pre-selected setting, this gap may not be the right one for your particular engine, and may not take into account modifications that you may have performed to the engine.
Insufficient spark plug gap can cause pre-ignition, detonation, even engine damage. Too much gap can result in a higher rate of misfires, noticeable loss of power, plug fouling, and poor economy.
When you raise compression or add forced induction (a turbo system, nitrous, or supercharger kit), you must lower the gap (reduce gap about .004" for every 50 hp you add on an V-8 engine, for a Harley-Davidson V-2 engine every 12.5 hp you add). However, when you add a high power ignition system (such as those offered by MSD, Crane, Nology,) you can open the gap back up about .002"-.005".
As an example, let's use a hypothetical `96 350 Chevrolet LT1 engine build-up. The standard gap is .050" for an un-modified LT1. We'll add 150hp Nitrous, so we must lower the gap about .012" to .038". We then decide to add that killer MSD 6A/Crane Hi-6 box and, using our guidelines as outlined above, we can now open the gap up .002"-.005" to about .040"- .043". By following this basic guideline should get you very close.
Further experimentation may be necessary, but by always starting with a larger gap than it thought necessary to reduce the risk of detonation, you should be safe.
Are plugs pre-gapped from the factory?
Yes and no. A spark plug part number might fit hundreds of engines, and although the factory will typically set gap to a pre-selected setting, this gap may not be the right one for your particular engine, and may not take into account modifications that you may have performed to the engine.
Insufficient spark plug gap can cause pre-ignition, detonation, even engine damage. Too much gap can result in a higher rate of misfires, noticeable loss of power, plug fouling, and poor economy.
When you raise compression or add forced induction (a turbo system, nitrous, or supercharger kit), you must lower the gap (reduce gap about .004" for every 50 hp you add on an V-8 engine, for a Harley-Davidson V-2 engine every 12.5 hp you add). However, when you add a high power ignition system (such as those offered by MSD, Crane, Nology,) you can open the gap back up about .002"-.005".
As an example, let's use a hypothetical `96 350 Chevrolet LT1 engine build-up. The standard gap is .050" for an un-modified LT1. We'll add 150hp Nitrous, so we must lower the gap about .012" to .038". We then decide to add that killer MSD 6A/Crane Hi-6 box and, using our guidelines as outlined above, we can now open the gap up .002"-.005" to about .040"- .043". By following this basic guideline should get you very close.
Further experimentation may be necessary, but by always starting with a larger gap than it thought necessary to reduce the risk of detonation, you should be safe.
burnt wire or 02 sensors... my 02 sensors went out awhile after putting longtubes on.. tha twas because i ran open headers for like 3k miles, it ran so rich with a bad 02...
When i installed my headers first problem were O2s. i would check the gap on the plugs stay away from ac delco rapid fire. I installed them on my car and had random misfire until went back with NGK. Just recheck your wires at night use a water bottle spray to see more clearly if it is the wires
Originally Posted by camarolvr69
would the car even run with a burnt wire??
O2s would set off a different code, as I have that right now as well lol