[Peter]

I have quite a big problem with misfiring. While driving on high rpm my engine is misfiring (only sometimes). No matter if boost is high or low. What do you think? My spark plugs are normal NGK (6000 miles old). What could be the reason?

 

[Steve Jarvis]

What gap are you running?

Later, Steve

 

[Peter]

I have NGK BKR6EP-11
1.1 gap

 

[The Flash]

Check the plugs on the coils my friend had the same problem and # 6 was loose. at any boost some times the car would run fine other times it was missing
most of his conectors were broken

laterz

 

[Ranger498]

try the ngk 3330 i was told befor to try gap sizes from .29 to .34

im right now at .34 and all seems well!some people have good results with .32 .29 so its sort of like a trial and errror job!

 

[RacerRT]

How are your spark plug wires? How long since they have changed? It sounds to me like you could have an arcing problem, or clean up your terminals on your coils, when you are experiencing constant, close pulses, you have a misfire, something is not making a complete conduction. My first guess would be wires.

 

[RSA Supra]

I would guess that after you were just asking if 2 bars it too much boost that you fouled out your plugs because your car was running hella rich to protect the engine.

Throw some new plugs in the car gap them down as suggested and see if that helps. If it doesn't then go to the coilpacks.

 

[Ranger498]

supras dont use spark plug wires !

How are your spark plug wires? How long since they have changed? It sounds to me like you could have an arcing problem, or clean up your terminals on your coils, when you are experiencing constant, close pulses, you have a misfire, something is not making a complete conduction. My first guess would be wires.

 

[RacerRT]

Wire Harness, same damn thing

 

[Ranger498]

lol ,

Wire Harness, same damn thing

 

[mkammeier]

Wiring Harness is not the same damn thing. Arcing comes from the high voltage leaking to ground or cross-firing through the spark plugs wires. Since the Supra has no distributor and no spark plug wires it uses a senor on the crankshaft and camshaft that signals low voltage to the coils that connect directly to the spark plug. No arcing is ever going to occur.

 

[Peter]

Big thanx to all of you guys!

I will check everything you have written.

Between coil and spark plugs is rubber part like o-ring - can't this cause my problem? Water could go thrue this rubber part = arcing???

What are 3330 NGK spark plugs - I can not find them in NGK catalogue? Do you have other [part number? Or mayby 3330 is part of longer part number?

Regarding gap - do you mean 0.29 - 0.34 mm ? Now I have 1.1 mm.


Thanx once again. You are like most fantastic family - Great!!!!

 

[Guest]

I have never tried the 3330's but from what i understand they have an extremely rough idle. I am currently using the ngk 6097's and am very satisfied, but make your decision

3330 pt. # - BCPR7ES
6097 pt. # - BKR7E

Hope this helps.

Chris

 

[Peter]

When should I put 3330, when 6097 and when 2978?

What gap is suggeted for each of type?

What are the differences? I know that 2978 (stock) is platinium and other are not!!!!

 

[Peter]

I was just talking to my mechanic and he said it is not good idea to change platinum spark plugs to non platinium like 3330!!!!

He said: Peter, DO NOT DO IT!!!

 

[Steve Jarvis]

Use the BKR7E. Gapped at .035 inches (.889mm). The copper plugs don't last as long, but at $2 ea. just replace them every 6 months and don't worry about it. They actually cunduct better than the platinum plugs. I have these in my car at my current hp level, so I don't think you will have a problem. I also used these in 2 BPU cars without a problem.

Later, Steve

 

[Ranger498]

3330 pt. # - BCPR7ES
6097 pt. # - BKR7E

either is good to try ..i was told to try the 3330 or 6097

or you can go the more expensive way and get the IK22 Denso Iradiums plugs!

read this old link


http://www.supraforums.com/showthread.php?s=&threadid=12242&highlight=spark+plugs