Fuel Power, spark plug picture

kevm14 · Nov 30, 2004

I've been using fuel power in my 95 Camaro Z28 for a few months now and I recently decided to replace my Bosch Platinum +4 plugs. Here is a picture of my #1 plug. The rest looked about the same.

Are those soft carbon deposits from the use of fuel power? The actual part that sparks is in fine condition, but I replaced them anyway. They had about 25k on them.
I drive the car plenty hard but I am worried that my combustion chamber, pistons and valves may have this same coating on them. What should I do?

Matt_S · Nov 30, 2004

quote:

Originally posted by cryptokid:
you cant see where the flame front goes based on cabron buildup. thats rubbish and wishfull thinking.

what you can see is that the tips of the ground straps get hot enough to burn carbon off, where as the base of the ground straps do not get hot enough to burn carbon off.

If the mixture was burning completely, the buildup on the base of the plug would not exist. These plugs are known to cause problems. I still say he should get them out of there, if he hasn't already done so. Besides, when plugs foul, the whole thing typically fouls, not just the base. He was getting incomplete combustion from this plug, plain and simple.

Bobert · Dec 1, 2004

The Bosch +4's are a crap shoot--some cars they work ok, most seem to have problems. The center electrodes on my +4's receded into the ceramic insulator and looked a range too hot with my VR6 on the front bank of cylinders. I'd say go with your OEM plug, or maybe a NGK equivalent.

kevm14 · Dec 1, 2004

I switched to NGK TR55 (3951), which are copper. I noticed no difference. BTW, all the plugs looked like this. I'll take a picture of all 8 lined up tonight after work. I think the problem with the +4s was that the center electrode sort of disintegrates and causes a misfire on that cylinder. Mine, I thought, all looked healthy in that department.

The car not only doesn't use oil, but after 5000 miles of hard driving (high rpm/light load, and everything in between), the oil is EXACTLY where it started on the dipstick. It's not from oil. I am also on my 2nd rinse of an Auto-RX treatment, so the rings should be in good shape. I've done a coil, ignition control module, EGR, cleaned stuff, seafoam, air filter - you name it, I've thrown it at the car.

It's also bone stock with a sequential fire fuel system with a relatively accurate ignition system metered by mass airflow (which I have cleaned with q-tips). However, I don't get great mileage (about 6-7mpg down from the highway rating) and I think I may have spark delivery problems. I am going to throw a set of Bosch Premium wires on the car, because I have had real good results with these wires on my other GM vehicle. The wires on the car are GM and have the same 25k on them. Same with the O2s and distributor (opti-spark).

Obviously, everyone can agree that something isn't right. 19mpg highway is not normal for a stock LT1 camaro when it's rated at 26.

[ December 01, 2004, 04:47 PM: Message edited by: kevm14 ]

kenw · Dec 1, 2004

Not sure about the root cause in your case, but old school experience says those have a bad air-fuel mixture. Why? dunno. But they do look awful.

perhaps you saw this pic of my 100,000 mile Bosch +4 from a 97 Camry v6.

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=45;t=000063

kevm14 · Dec 1, 2004

That's more like what the plug should look like. And while the carbon that's there didn't compromise spark performance, it IS indicative of a problem, as you guys have mentioned. I am pretty sure this explains my bad mileage and emissions results from last July. Excuse me while I paste from another board:

quote:

All figures are in GPM (grams per mile)
HC: 2.17/2.25
CO: 12.29/23.74
NOx: 2.96/3.25
CO2: 699.22

These results struck me as particularly dirty in an engine that has a reputation (at least in the b-body community) of being just as clean as brand new engines. Despite the fact that my cat probably wasn't fully warmed up yet, these results are indicative of a problem.

It's pretty obvious that some of my mixture is blowing right out the exhaust port by the HC results (and mileage). The car has been like this for months, despite throwing random parts at it. Wires are next...
BTW, I have the ability to re-flash my PCM so if anybody has any neat tricks I can try to narrow down the problem, I am all for it. I already tried forcing the car to run in speed density mode. Oddly, my long term fuel trims are not out of whack. With unburned mixture running into the exhaust, one would expect fuel trims to be high, when the O2s see all that extra O2. I hate problems with seemingly conflicting data.

uconn1150 · Dec 1, 2004

I'd definitely clean out the CC. It's only going to get worse even with new wires. You may want to switch out the new Bosch ones for any others while you do this. You don't want that carbon crud ending up on your new plugs!

Big Jim · Dec 1, 2004

What you are seeing on the base of the plug is from a rich fuel mixture, probably only part of the time. It is not from oil burning.

I would guess that once the engine is up to proper operating temperature that the black burns off at least near the plug tip.

Although I don't care for Bosch plugs in general and +4 in particular, I doubt that the plug is causing your problem. I suspect that it is running too rich during warm up, that you have a fuel quality problem, or that your thermostat is too cold or is stuck open.

I would be looking for something that is causing the engine to run too rich at times, probably during warm up.

As light as the carbon deposit is on the plug, the combustion chamber should clean up OK once you have corrected your problem. It would not hurt to de a decarbon for maintenance though.

jeremiah2360 · Dec 1, 2004

I run the +4`s in my 03 Dakota 4.7. I`ve seen them start out fine (light grey) , then be sooty , to looking like they were sand-blasted

(like the top part of the plugs in the picture,but the whole exposed area). I attribute the sand-blasted look to FP(I checked after a few tanks of FP treated gas).

The truck seems to like the +4`s better than stock and it runs good so I left them in. I`ll pull a couple of pugs next chance I get and report back.

If the sand-blasted look is not good please let me know.

Thanks

Mr Nice · Dec 1, 2004

When the Bosch Platinum + 4 plugs first came out , I installed them on my wife's Honda Civic EX. The motor didn't misfire, but seemed sluggish from idle to redline .....compaired to the factory NGK. After 45,000 miles on the + 4 plugs, i replaced them with NGK's and i noticed a big difference. I dont know how good the NGK 'Platinum' plugs perform in Hondas.

Has anyone put tired Platinum NGK's in a Honda???

kevm14 · Dec 1, 2004

quote:

Originally posted by Big Jim:
I suspect that it is running too rich during warm up, that you have a fuel quality problem, or that your thermostat is too cold or is stuck open.

I would be looking for something that is causing the engine to run too rich at times, probably during warm up.

My thermostat functions great. This car warms up in minutes, even when it was started below freezing. And it runs right at 195*F as long as there is an adequate airflow through the radiator. I also highly doubt it's running too rich when cold, as my coolant temp sensor and MAF sensor are in good working order, according to my PCM data logging. I think it's inadequate spark causing an incomplete burn. It would explain the carbon, the bad mileage and the almost-failing emissions test. The question is, what is the cause? As soon as I can track down some Bosch wires, I'll see if they are the culprit.

alchu · Dec 1, 2004

quote:

Originally posted by Bobert:
The Bosch +4's are a crap shoot--some cars they work ok, most seem to have problems. The center electrodes on my +4's receded into the ceramic insulator and looked a range too hot with my VR6 on the front bank of cylinders. I'd say go with your OEM plug, or maybe a NGK equivalent.

12v vr6's HATE Bosch +4s... stick with the OEM NGK's...

Gary Allan · Dec 1, 2004

quote:

By the way, just look at the pattern of the carbon buildup. You can see exactly how the flame is propegating.

Well I just pulled Plus 4s out of my jeep. You can't see anything like that on them. You can on my stock Autolites. They show a "shadow" where the flame/fuel charge is sheltered by the plugs protrusions. You can't see this with the Plus 4 ...because its 3/8 of an inch shorter than the OEM.

Compare one of your shot Plus 4 to an OEM plug and compare how far it actually goes into they combustion chamber. There was so much difference for me ..that I was afraid to put the OEM spec'd plug in there because I thought they gave me the wrong plug. I found my originals and confirmed that indeed the Plus 4 was substantially shorter than the OEM.

sprintman · Dec 1, 2004

I have NGK Iridiums (a step up from Platinum) in both our vehicles. The owner of the dyno shop I use fitted them to his cars after seeing how well they worked in mine. I could feel the difference immediately.

kevm14 · Dec 1, 2004

I took two pictures of all 8 plugs. Like I said, they were all about the same.

novadude · Dec 1, 2004

Black crusty deposits around the base of the plug could be a sign of worn valve guides / seals letting oil into the chambers. How's oil consumption?

I have seen this a lot on high mileage Chevy V8s.

EDIT: I just noticed that the car uses no oil. I'd imagine it would not take more than a few oz seeping past the guides over many miles to leave these deposits.

Bobert · Dec 1, 2004

Those plugs are definitely worn out. The center electrodes are not round anymore and are starting to recede. My center electrodes were literally pinpricks when I pulled them, but yours don't look quite that bad.

I'd say your better off with the NGK's, and it looks as if your combustion chambers have a lot of carbon deposits. All that black carbon you see around the circumference of the plug is probably what your combustion chamber looks like. I know people in here like FP, but I'd try something like Redline SI-1 to start cleaning up the combustion chambers. FP from what I've seen works kinda slow and might take a long time to clean up CC deposits.

Matt_S · Dec 1, 2004

If this is the first time you've pulled these particular plugs, there's no way you can say the FP caused it. The Bosch +4s are infamous for having a big weakness, though, which I think is a much more likely cause of the carbon buildup. All those extra electrodes get in the way of the flame propegation inside the cylinder, resulting in incomplete combustion. The result is poor performance and carbon buildup.

I'd recommend you switch back to the OE plug. GM's ignition system designs have always been quite good and very efficient. I'd stick with that. Besides, if you look at the stock plugs on just about any production car, they all have a single ground electrode. That should tell you something.

jthorner · Dec 1, 2004

Are you burning any oil? Is the mixture right?

Those plugs look to me like they are from a car which is either running a little rich or is burning some oil.

Not bad for 25k miles, but not great.

John

Matt_S · Dec 1, 2004

By the way, just look at the pattern of the carbon buildup. You can see exactly how the flame is propegating. The very tip of the plug is perfectly clean and looks just fine. The base is what has all the carbon buildup. This is why I say the flame is not propegating properly and the mixture is not burning completely. Your cylinder head is probably covered in carbon by now. If you just put new +4's in, I'd get them out of there and go back to stock.

Fuel Power, spark plug picture

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