spark plug question???

[stangbangin69]

what would make 1 spark plug on 1 cylinder look different than the rest? all the other plugs look fine. this is like 5 miles after the plug change but on cylinder 3 the plug looks a lil blacker and the porcelain is dereriorating. they are gapped at .035 and if i turn the boost up past 19psi it will backfire a bit.
o2's are around 760-810.

 

[278cikiller]

Spark plug

What miles are on the motor? Has the motor ever been rebuilt?

 

[stangbangin69]

yes motor was rebuilt with forged internals. not sure on the miles though. the guy i got it from was unsure on the miles.

 

[Royal-T-Ltd]

what would make 1 spark plug on 1 cylinder look different than the rest? all the other plugs look fine. this is like 5 miles after the plug change but on cylinder 3 the plug looks a lil blacker and the porcelain is dereriorating. they are gapped at .035 and if i turn the boost up past 19psi it will backfire a bit.
o2's are around 760-810.

they probably need to be gapped tighter for your higher boost.... you are probably blown the flame out - i gap mine at a tight .032 and run 25#s....

number 3 might be getting a little more fuel maybe the injector flows more than the rest or is leaking a lil' - how old are the injectors.... did you double check and make sure the wires are on tight?

 

[turbo tom]

Denso spark plugs

Has anyone had any luck using these Desco spark plugs?

 

[turbo tom]

Denso spark plugs

Anyone have any luck using these plugs?

 

[stangbangin69]

i'll try closing the gap between .030 and .032 and see what happens. i changed out my coil only to find a big ole glob of green nastiness inside the module. i put it back together and the car won't run for crap now. looks like it's module time.. $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

 

[278cikiller]

Spark plug

RTS44 are for stock motors up to 16 pounds of boost RTS43 and 42 are for 17 and over tight 35 or 33 will work if that helps.

 

[bad V6]

What does the #1 plug look like, in comparison to the others? What plug are you running? Be sure not to run too cold of a plug or an improperly gapped plug. Sounds like you may have found the problem, module headed south.

I run Autolite 24, gapped at .32 and the car doesn't skip a beat, pump gas and alky, set at 24# boost.

 

[stangbangin69]

i run ngk ur5's. were gapped at .035 gonna try them at .032 when i get a new module. #1 plug looks fine as well as all the others except for #3. thnx for all the replies. gotta love the buick community!

 

[Just a Six??]

i run ngk ur5's. were gapped at .035 gonna try them at .032 when i get a new module. #1 plug looks fine as well as all the others except for #3. thnx for all the replies. gotta love the buick community!

Use the GM or Autolite plugs & forget the NGK stuff.

 

[278cikiller]

Spark plug

you might have a cam lob on number 3 cylinder wipe its comon on 3.8 motors do a comprestion test and see the difference.

 

[Royal-T-Ltd]

Use the GM or Autolite plugs & forget the NGK stuff.

NGK UR5s ftw..... been using them for years - NEVER a problem - gapped at .032

nothing wrong with delco cr42ts - but ive NEVER had problems with the NGKs and they seem to idle better and last longer

 

[stangbangin69]

you might have a cam lob on number 3 cylinder wipe its comon on 3.8 motors do a comprestion test and see the difference.

i thought about that after hearing stories on the board here. oh well. i've yet to do a compression test. will that show a wiped lobe??? i thought i had to pull a lifter or even the cam. i haven't seen any signs of metal in the oil yet either.

 

[bad V6]

The easiest way to determine if a cam lobe is going south, is to unplug the ECM wire at the battery, remove the driver side valve cover and have someone turn the motor over. You'll need to be watching for less movement in the valvetrain. The #3 exhaust will be the most likely culprit if this be the case.

A compression test will show the condition of each cylinder and the probability of either a worn cylinder bore and poorly sealing rings, problems with the valves sealing, or possibly a headgasket issue.

In order to prevent a problem with cam lobe failure, there are a few types of oil or additives that can be used. There is a lot of info on the board about this.

 

[stangbangin69]

yep, i've read up on the oil. that's the problem with getting a modded car. don't really know it's history. u have to go by what someone else is telling ya. i did take the d.s. valve cover off and disconnected the ecm, had the wife turn the engine over. all the cylinders look like they move up and down equally in length. that's just eyeballing it though. still need to do a compression test just for ****s and giggles to make sure things are g2g.