cracked spark plugs around white housing - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

toledo240 · 06-09-2006, 09:08 AM

I have a redtop sr20. Running off of bkr6e's. I keep on cracking the white part on the plugs and causes bad detenation. It running lean when at had it a 12psi but now im back to stock boost and i ant get the problem to go away. It sounds like my car is running off 3 cylinders or sounds real low like an sti motor or something. Give gas to pedal causes smoke out the exhaust, (more than usual)i think this is running rich. Everything ive done is check for spark, check connections. Im thinking my fuel pump went bad

AuburnRyan · 06-09-2006, 09:26 AM

Check gap is at ~ .0029. Try the BKR7E - I imagine they're cracking because they're too hot...

Sorry, confusing post, first you say leanat 12psi, then rich at 7psi?

Have you upgraded the fuel system?

toledo240 · 06-09-2006, 10:09 AM

i figured it out messing with the gap of the spark plugs, i was running a larger gap. but now with the gap at about .32 i get a lot of smoke out of the exhaust more than usual and smell alot of gas, is that because i shorten the gap? anything i can do about that. im running not cat or no afc

smithers584 · 06-09-2006, 02:08 PM

well first off .32 is way too big, try .032! im sure that was a typo, right? anyways, you could go smaller, .028-.032 is usually a good way to go. how do you know if you are running lean or rich? and the cracking is either due to heat or detonation so try and get on a dyno or get a wideband and see exactly what you are at for afr. highly doubt your fuel pump went bad, are you sure you have the vacumm line on the fpr hooked up? that would cause it to run a little more rich, what about vacumm leaks have you checked for those? are you plugs are fouled up or are the white or are they a good tan? need a lot more info.

06-09-2006, 09:08 AM	#1
toledo240 Zilvia Member Join Date: Apr 2004 Location: toledo Age: 39 Posts: 281 Trader Rating: (0) Feedback Score: 0 reviews	cracked spark plugs around white housing I have a redtop sr20. Running off of bkr6e's. I keep on cracking the white part on the plugs and causes bad detenation. It running lean when at had it a 12psi but now im back to stock boost and i ant get the problem to go away. It sounds like my car is running off 3 cylinders or sounds real low like an sti motor or something. Give gas to pedal causes smoke out the exhaust, (more than usual)i think this is running rich. Everything ive done is check for spark, check connections. Im thinking my fuel pump went bad

06-09-2006, 09:26 AM	#2
AuburnRyan Zilvia Member Join Date: Aug 2002 Location: Northern VA Posts: 272 Trader Rating: (0) Feedback Score: 0 reviews	Check gap is at ~ .0029. Try the BKR7E - I imagine they're cracking because they're too hot... Sorry, confusing post, first you say leanat 12psi, then rich at 7psi? Have you upgraded the fuel system? __________________ '93 Fastback LE - Wrecked '91 Fastback HICAS and LSD - Sold '93 Fastback SE - Current

06-09-2006, 10:09 AM	#3
toledo240 Zilvia Member Join Date: Apr 2004 Location: toledo Age: 39 Posts: 281 Trader Rating: (0) Feedback Score: 0 reviews	i figured it out messing with the gap of the spark plugs, i was running a larger gap. but now with the gap at about .32 i get a lot of smoke out of the exhaust more than usual and smell alot of gas, is that because i shorten the gap? anything i can do about that. im running not cat or no afc

06-09-2006, 02:08 PM	#4
smithers584 Zilvia Junkie Join Date: Dec 2004 Location: sc Posts: 416 Trader Rating: (0) Feedback Score: 0 reviews	well first off .32 is way too big, try .032! im sure that was a typo, right? anyways, you could go smaller, .028-.032 is usually a good way to go. how do you know if you are running lean or rich? and the cracking is either due to heat or detonation so try and get on a dyno or get a wideband and see exactly what you are at for afr. highly doubt your fuel pump went bad, are you sure you have the vacumm line on the fpr hooked up? that would cause it to run a little more rich, what about vacumm leaks have you checked for those? are you plugs are fouled up or are the white or are they a good tan? need a lot more info.