Do I need hotter plug?
Thread Starter
Instructor
Joined: Aug 2001
Posts: 168
Likes: 0
From: Atlanta GA
Do I need hotter plug?
You can see by the signature description of my 90, it's not stock. Yesterday, car ran really bad, and backfired several times even at idle. I've removed the plugs and I believe that at least six out of eight may be fouled. They are black, wet, and deposits appear to have "crystalized".
The plugs I'm running are NGK FR4's, but I"m wondering if I should be running a slightly hotter plug to burn off these deposits before they form? Given my heads, injectors, etc., does anyone have a suggestion? Thanks for all your help. :flag
The plugs I'm running are NGK FR4's, but I"m wondering if I should be running a slightly hotter plug to burn off these deposits before they form? Given my heads, injectors, etc., does anyone have a suggestion? Thanks for all your help. :flag
Melting Slicks
Joined: Mar 2003
Posts: 2,898
Likes: 0
From: Oklahoma City Oklahoma
Re: Do I need hotter plug? (WHRITZY)
I'm not a master mechanic, but if I remember my high school mechanics class right, spark is spark. Hot plugs don't "fire" hotter. The electrodes in the plugs just retain heat longer.
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: Do I need hotter plug? (Klimper)
I'm not a master mechanic, but if I remember my high school mechanics class right, spark is spark. Hot plugs don't "fire" hotter. The electrodes in the plugs just retain heat longer.
As far as the heat range on the plug....more thank likely the wet residue on the plug feels oily. If so you either are wearing out your rings, or your valve seals or guides are worn and you're getting oil into the combustion chamber. If it's not oily, then it's either unburnt fuel (which could be the result of a misfire, or the engine having been shut off during the intake or compression stroke) or it's coolant. However, if the engine had been running for more than a minute or two, you shouldn't have any fuel or water dampness on the plug, as the heat of the electrode would have evaporated it.
Thread Starter
Instructor
Joined: Aug 2001
Posts: 168
Likes: 0
From: Atlanta GA
Re: Do I need hotter plug? (WHRITZY)
Thanks, fellas....I'm pretty sure it's unspent fuel...car only has 26k on it so unless somethings REALLY wrong, rings and valve seals, etc., should be fine. Not oily...just wet looking and black. This car uses great amount of fuel/fuel pressure to reach the maximum hp it's capable of. On dyno, rev limiter doesn't set in until 6200 rpm and it pulls all the way to that rpm range.
Someone told me that with the way the car is now, I probably will have to take out plugs and change or clean about every 2000 miles or so...just the nature of the beast.
Still is search of some suggestions for plugs.....guess I was unaware one plug was not "hotter' than another....
Someone told me that with the way the car is now, I probably will have to take out plugs and change or clean about every 2000 miles or so...just the nature of the beast.
Still is search of some suggestions for plugs.....guess I was unaware one plug was not "hotter' than another....
