spark plugs, help!!!!!!!!!!!!!!!

[plumcrazy]

hey everyone,

got a real problem that i cant seem to put my finger on.
the vette started running a little bit rough the other day
and wasnt sure why. it started to miss and stumble
under a moderate 50 mph climb up a long hill on the way
home. got to look at the car finally today, i checked
the timming,fuel pressure, plug wires,air filter and all are
ok. this i the strange part, i pulled the #1 plug and it had
bridging and ash build up like you wouldnt believe. thought
was it so just to be sure i pulled #2 and it was the same way
as were the rest of the plugs? the plug are bosch plat+4's
w/ less than 3000 miles on them.i just dont understand how
the car ran the way it did. what could cause this to happen
i can roast the tires and sit myself back in the seat pretty good
under acceleration.

any and all help would be greatly appreciated

thanks,
chris

 

[Ken Anderson]

Install AC's and all your troubles will go away.

 

[KOPBET]

Engine oil is probably getting to your plugs from either worn piston rings or valve guides/seals.

Does it burn oil?

Mileage?

 

[Vettefan87]

I wouldn't run Bosch. Either run the regular ACDelco replacements or if you want to spend a little more money get the ACDelco Rapidfire plugs, the car will idle a little smoother and run a little better. They are a little more pricey at about 30 bucks though.



Justin

 

[rrubel]

I had a set of Bosche platinum +4's that did that in under 2k miles. You're probably burning a little bit of oil, and these plugs just won't handle it. Waste of money. Try AC Delco RapidFire #5's.
[RICHR]

 

[Hib Halverson]

Bosch "Platinum +4s" are great marketing but a sucky spark plug.

An 85 has iron heads so I'd ignore the advice to use Rapid Fire 5s. You'll have a hell of a problem with them as they are 3/4-in. reach and your engine uses .460-in. reach plugs.

If the car gets driven easy, is a show car or sees starts-without warm ups use the Rapid Fire #1. If you drive the car hard try the RF2.

 

[KOPBET]

Bosch "Platinum +4s" are great marketing but a sucky spark plug.

An 85 has iron heads so I'd ignore the advice to use Rapid Fire 5s. You'll have a hell of a problem with them as they are 3/4-in. reach and your engine uses .460-in. reach plugs.

If the car gets driven easy, is a show car or sees starts-without warm ups use the Rapid Fire #1. If you drive the car hard try the RF2.

Aside from the +4s being a sucky spark plug, the ash fouling has to be coming from someplace does it not? Wouldn't either plug you mention be susceptible to ash fouling also? Or does this condition have other root causes other than combustion by-products.

 

[rrubel]

Oh boy... glad I didn't use them in my CI '86 motor. They were sold to me as a replacement for the +4's. Kept them out until I got the AL heads in, though.

I've got a set of new Accel shorty (header) plugs here for CI heads if anyone wants them cheap...

Kopbet, I'm of the opinion that the +4's design makes it foul more easily. I had no problems with the normal AC Delcos in the engine right before those, but went with the Bosch because I believed the marketing hype. "Duh! Look! It's like a SplitFire, but BETTER!"

[RICHR]

 

[Edmond]

I've had my +4's in there for almost 2 years and haven't had any problems. But it looks like I'll be going back with Delco's when I change them next. The +4's were pretty pricey at $6.00 a plug!

Is everyone here pretty much going with plantinum plugs?

 

[sherry_ridgeway]

hi
try replacing the same plug first and check the gap setting on the old one, it may have gotten bent or out of alighnment during install ,or got hot and expanded , my guess is its a valve ,but possibly a new plug in that particular cylinder might help burn out the impurities and help for a little while at least until you can find the problem also be sure to check the plug wires etc
Sherry the replubrocrat

 

[plumcrazy]

thanks for all the help everyone. i do know the valve seals are bad so that
might be what is killing my plugs. got a set of delco plugs to throw in to
see what happens. what would be the proper gap for them. i think i saw
some where that the recommended gap was change but cant find where i
saw it at. once again thanks for all the help.

chirs