White Spark plugs & very warm engine - JeepForum.com

 
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post #1 of 8 Old 10-17-2013, 04:40 PM Thread Starter
bmx4flowers
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Yesterday i put a new valve cover gasket in so after my drive home from school i popped the hood just to check on it. My engine was extremely hot (only a 3 mile drive). I decided to pull my plugs to check them first. They were very white, little bit of black on the top of the threads, but the electrodes where a very dry white. Now i know that my Fuel Check valve is compromised, i have been starting it for the past year by priming the pump a few times before cranking it. Could this have anything to do with the engine running lean? Not enough fuel to the injectors? Or could it be that the injectors aren't spraying enough fuel? I check my air filter and it looks fine also. Here are a few photos of plugs from different cylinders. All look the same. Name:  image-518749855.jpg
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1998 Cherokee Limited Sport
Mods-RE3.5 full Leafs, 3.5 coils with spacer, 1.5" TC drop, 31x10.50R15 General grabber AT2's, Cragar soft 8's, Custom front bumper, Custom swing-out tire carrier rear bumper
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post #2 of 8 Old 10-17-2013, 05:34 PM
Diamond-x
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It looks like you're running platinum plugs. I've always sworn by the Champion stock style.

Check your fuel pressure to see if your pump is up to snuff. Also your fuel presuer regulator has a vacuum hose to the manifold, if it's leaking your pressure will be less than desirable. Couldn't hurt to change your fuel filter and run some injector cleaner through.

Please let us nkow your results, it's good to have a fix related to these type of issues.

I hope this helps!
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post #3 of 8 Old 10-17-2013, 06:02 PM
tjwalker
It's the crank sensor!
 
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Could be a "lean burn" condition.....those plugs are a little too white for my liking. Tan/beige is where you want them.

No, the failing check valve would not be involved here. That would create a fuel pressure bleed down which makes for longer starts, but will not affect the fuel/air ratio.

I agree with Diamond-x. First thing I would do is to get a fuel pressure gauge and verify fuel pressure. I would also test the MAP sensor, which has an effect on fuel/air ratio. Be sure that the vacuum line leading to the MAP sensor is pulling good engine vacuum.

Other things to consider.....are you using any coolant? Are you using frequent fuel additives?

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Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!
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post #4 of 8 Old 10-17-2013, 08:44 PM Thread Starter
bmx4flowers
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Quote:
Originally Posted by Diamond-x
It looks like you're running platinum plugs. I've always sworn by the Champion stock style. Check your fuel pressure to see if your pump is up to snuff. Also your fuel presuer regulator has a vacuum hose to the manifold, if it's leaking your pressure will be less than desirable. Couldn't hurt to change your fuel filter and run some injector cleaner through. Please let us nkow your results, it's good to have a fix related to these type of issues. I hope this helps!
I have heard not so good things about those plugs also. To be honest i haven't looked at them since i bought last December, If i can confirm that they are Platinums i will replace them with champions right away! I will pick up some injector cleaner, and i plan to tackle the pressure check valve/filter when my gas light turns on next. Thank you.


Quote:
Originally Posted by tjwalker
Could be a "lean burn" condition.....those plugs are a little too white for my liking. Tan/beige is where you want them. No, the failing check valve would not be involved here. That would create a fuel pressure bleed down which makes for longer starts, but will not affect the fuel/air ratio. I agree with Diamond-x. First thing I would do is to get a fuel pressure gauge and verify fuel pressure. I would also test the MAP sensor, which has an effect on fuel/air ratio. Be sure that the vacuum line leading to the MAP sensor is pulling good engine vacuum. Other things to consider.....are you using any coolant? Are you using frequent fuel additives?

They are the whitest and driest looking plugs i have ever seen. Tomorrow i will run a test on the fuel pressure, i will also do the MAP sensor. Is that something i can do with my Multimeter or should i remove it and bring it to Auto part store? She is using up lots of coolant, i just found the resi almost empty tonight, with lots of air in the system. Never ran any fuel additives.

1998 Cherokee Limited Sport
Mods-RE3.5 full Leafs, 3.5 coils with spacer, 1.5" TC drop, 31x10.50R15 General grabber AT2's, Cragar soft 8's, Custom front bumper, Custom swing-out tire carrier rear bumper
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post #5 of 8 Old 10-18-2013, 05:10 AM
tjwalker
It's the crank sensor!
 
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Quote:
Originally Posted by bmx4flowers View Post
She is using up lots of coolant, i just found the resi almost empty tonight, with lots of air in the system.
This is what I would concentrate on first. If you have to add significant coolant, you're either leaking it or burning it.

Perform a comprehensive search for a leak from underneath with a good light. If you can't find a leak and don't have any tell-tale coolant puddles on your driveway, I'd highly recommend you get to the bottom of why it is using coolant. Start with a cooling system pressure test, then a compression test or even better than the compression test is a cylinder leakdown test.

99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!
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post #6 of 8 Old 10-18-2013, 09:06 AM
CCKen
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Those plugs may simply be the wrong heat range.

Install a set of Champion RC12ECC plugs or NGK FR5-1 plugs (preferred) and run them for awhile then recheck them.

If you can access a scanner that shows live data you could check the Short Term Fuel Trim while the engne is running at idle and at 2000 RPM. The STFT will show if you are running lean. STFT will be (+) numbers, meaning fuel is being added by the PCM to compensate for a lean condition.
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post #7 of 8 Old 10-18-2013, 03:30 PM Thread Starter
bmx4flowers
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Quote:
Originally Posted by tjwalker
This is what I would concentrate on first. If you have to add significant coolant, you're either leaking it or burning it. Perform a comprehensive search for a leak from underneath with a good light. If you can't find a leak and don't have any tell-tale coolant puddles on your driveway, I'd highly recommend you get to the bottom of why it is using coolant. Start with a cooling system pressure test, then a compression test or even better than the compression test is a cylinder leakdown test.

I just added 3/4 of a gallon of coolant, burped all the bubbles out. And now she is pissing coolant all of the place from the top radiator fill hole. But not from the cap, it looks like there is a crack in the plastic. I will further inspect that. Also now that is is full of coolant i pulled her in the garage so i can monitor for leaks. I will look into get those tests done ASAP. Thank you...


Quote:
Originally Posted by CCKen
Those plugs may simply be the wrong heat range. Install a set of Champion RC12ECC plugs or NGK FR5-1 plugs (preferred) and run them for awhile then recheck them. If you can access a scanner that shows live data you could check the Short Term Fuel Trim while the engne is running at idle and at 2000 RPM. The STFT will show if you are running lean. STFT will be (+) numbers, meaning fuel is being added by the PCM to compensate for a lean condition.

New set of plugs are going in today. Most likely will go with the NGK's. When you say a while what do you mean? A week or a month? I will try to get access to a scanner with live time data, but if i can't what is another way to check the fuel trim?

1998 Cherokee Limited Sport
Mods-RE3.5 full Leafs, 3.5 coils with spacer, 1.5" TC drop, 31x10.50R15 General grabber AT2's, Cragar soft 8's, Custom front bumper, Custom swing-out tire carrier rear bumper
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post #8 of 8 Old 10-18-2013, 06:10 PM
CCKen
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Quote:
Originally Posted by bmx4flowers View Post
New set of plugs are going in today. Most likely will go with the NGK's. When you say a while what do you mean? A week or a month?

A fair comparison would be the same amount of time/miles you had those other plugs in.

I will try to get access to a scanner with live time data, but if i can't what is another way to check the fuel trim?
There is no other way.
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