Engine issues fouled pulgs

[Southenrfirewood]

My 98 3.0 ranger keeps fouling the same 3 plugs after a few hundred miles. The tips on the keep melting down. Its not burning oil. I also keep getting a code P1151 and iv changed about all the sensors involved with that code except the sensor on the middle of the intake between the air filter and the throttle body. The reader says P1151 and Fuel air metering. Also I did a compression test 5 cylinders were between 120 and 130. except number 6 which is at 110. I put some oil in the cylinder and it went up to 140. One of the cylinders that keeps fouling is the one at 110. Thoughts, inputs, suggestions?

 

[Southenrfirewood]

Nobody on here likes messing with motors?

 

[Andy D]

The electrodes are melting ? Or just getting fouled? Melting electrodes is high heat. Running too lean will do that. Does the engine ping under load? Detonation will eat up a plug after awhile. Need more info

 

[Cody Ray]

If just fouled the injectors might be leaking.

 

[LearjetMinako]

What spark plugs are you using? Are they getting carbon fouled or tip melting?

 

[adsm08]

If just fouled the injectors might be leaking.

I don't think it's leaking injectors. If anything with injectors it's plugged injectors.

I believe the actual definition is HO2S21, lack of switching, Lean. So despite the fact that you have not told us which 3 plugs keep melting, I'll bet that it is 4,5, and 6.

A 10 PSI variance is acceptable. More than 10% loss is when you need to start worrying.



Now, actually melting plugs means high heat. Lean conditions in a gas engine actually raise the temperature. So far, it is all consistent with your issue.



A perceived (by the oxygen sensor) lean condition caused by excessive oxygen in the exhaust. This can be from an incorrect air/fuel ratio, incomplete combustion, or a large exhaust leak upstream of the sensor.


Now, when the computer sees lean, if commands more fuel, up to a certain point, then it says something is wrong. I'd say you have a LOT of extra air in the cylinder. That kinda tells me it's not likely to be an exhaust leak.

A bad intake gasket will usually set a P0171/4 (straight lean codes) long before setting switching codes. Also knocks it off my list of top suspects.

This leaves incomplete combustion, or lack of fuel delivery.

If you are fouling plugs then you probably have leaking injectors. If you are slagging plugs you probably have stuck injectors.

Either way, I would suspect the injectors.

 

[Cody Ray]

I don't think it's leaking injectors. If anything with injectors it's plugged injectors.

If you are fouling plugs then you probably have leaking injectors. If you are slagging plugs you probably have stuck injectors.

Either way, I would suspect the injectors.

His thread title says fouled plugs, hence leaking injectors. If it is melting, it would be the exact opposite. Needs to decide which it is.

 

[doorgunner]

He needs to resubmit the question....even I know that the symptoms/wording don't make sense:

My 98 3.0 ranger keeps fouling the same 3 plugs after a few hundred miles. The tips on the keep melting down. Its not burning oil. I also keep getting a code P1151 and iv changed about all the sensors involved with that code except the sensor on the middle of the intake between the air filter and the throttle body. The reader says P1151 and Fuel air metering. Also I did a compression test 5 cylinders were between 120 and 130. except number 6 which is at 110. I put some oil in the cylinder and it went up to 140. One of the cylinders that keeps fouling is the one at 110. Thoughts, inputs, suggestions?

fouling means what...sooty/oily/wet-with-fuel/melted?

I'm guessing his definition of fouling means melted plug electrodes (not sooty/oily/wet-with-fuel old school definition) because ther's no oil usage & compression looks O.K.

so....different heat range spark plugs needed or/clean-replace injectors or/faulty wiring to injectors on problem cylinders???????????????

 

[Southenrfirewood]

The electrodes are melting, on the same 3 holes. Also compression of 110 in one hole would be a problem wouldn't it? Iv never messed with injectors before, can you clean them or do I have to buy new ones?

 

[Southenrfirewood]

Oh and I was using autolite's but they foul out after like 150 miles, I started using motorcraft and they last a little bit longer but still fail shortly after putting them in

 

[doorgunner]

just don't melt a hole in the top of the pistons!!!

 

[robertc1024]

Or burn your exhaust valves. Mr. Firewood - read the thread. Fouling is when the plugs are getting too much fuel/oil. Do not call burning the electrodes off fouling. It is the opposite - your mixture is too lean. If they are fouling, they'll be black, if they are running too lean, they will be almost white. Perfect is light brown/beige. I'm with Adsm08 as usual. I bet you've got a plugged/stuck injector.

 

[adsm08]

The electrodes are melting

Oh and I was using autolite's but they foul out after like 150 miles

Ok. Make up your mind. Are they fouled, or are they melted? These are not the same thing. Gonna be a dick here for a second, but bear with me and I am trying to make my point perfectly clear.

Fouled:

Melted:

Fouled:

Melted:

Fouled:

Melted:

Which one is it?

Also compression of 110 in one hole would be a problem wouldn't it?

It does constitute a numerical problem. 10% loss from the highest to the lowest is generally the acceptable limit. 130 to 110 is about 12%.

I wouldn't worry about that too much just yet. Your issue is affecting an entire bank and it is wiping out your spark plugs. If anything, your 110 PSI is probably gas wash on the cylinder walls. Get the fuel system issue fixed, fresh plugs and oil, and it will probably clear itself up.

 

[Southenrfirewood]

They are melted but not that bad lol

 

[Insanejughead]

Adsm, I may be going out on a limb here by pointing this out, but I think that the first, third, and fifth picture are the same ones. I just want to make sure you know that copy and pasting the picture url three times in a post, in actuality, does not create three different pictures.

I'm still mulling over the second, fourth, and sixth pictures. Something about them seems similar, but I haven't pinpointed it yet.




OH WAIT, I'VE GOT IT! Those even numbered pictures of spark plugs aren't ranger specific plugs, at least as far as I can tell. The threads do seem to be a might short for a ranger's cylinder head.

Also, why would you use German engineered plugs in an American vehicle? I know the 2.9 engine block was a modification of the Euro designed 2.6 but you don't have to keep using German plugs. I think you definitely set yourself up for failure by doing so.



However, since we're on the issue of f***ed up plugs, check this one out!