running rough????

[talincolnlsc]

i have a 92 x and im having trouble getting it to run right. it misses at any rpm and i cant figure it out.has good compression and fuel pressure,i replaced plugs, wires, and coil pack. the truck has no power and i replaced the plugs yesterday and they are already covered in carbon. so could an 0 2 sensor do this? maybe computer? or another sensor? any help to point me in the right direction would help me alot.

 

[lycan91]

me i would check the o2 sensor first then if thats not black or it looks in good shape check else where but me i would check o2 (with the plug problem) rough idle i would check your timing Yah check your timing and repost it sounds like your timing may be causing your idle and power problems if it is missing badly

 

[talincolnlsc]

timing is at 10 degrees

 

[pughman]

Search Forums

 

[talincolnlsc]

ive searched forums and came up with nothing. i just figured someone on here would know about explorers since it is an explorer forum.

 

[lycan91]

i tryed is 10 degrees normal?

 

[lycan91]

what if your cat has a slight blockage would that cause a explorer to miss? maybe you have a blown gasket

 

[pughman]

ive searched forums and came up with nothing. i just figured someone on here would know about explorers since it is an explorer forum.

no you did not ! "Showing results 1 to 15 of 660, Search took 5.97 seconds. Search: Key Word(s): running, rough" this is what i got

and if you cant find it in "running, rough" try MAF, IAC, O2 sensor, etc.

 

[talincolnlsc]

your right.my bad i did come up with plenty of info through a search. it turns out that i was doing the search wrong. thanks and when i find the problem i will post.

 

[4x4rob]

no you did not ! "Showing results 1 to 15 of 660, Search took 5.97 seconds. Search: Key Word(s): running, rough" this is what i got

and if you cant find it in "running, rough" try MAF, IAC, O2 sensor, etc.

Good grief!!! Could this reply be any more useless? If you don't know, don't reply. If you have better things to do with your 5.97+ seconds, don't read it or hit the "back" button.

 

[moose1]

lol...

 

[Rick]

no you did not ! "Showing results 1 to 15 of 660, Search took 5.97 seconds. Search: Key Word(s): running, rough" this is what i got

and if you cant find it in "running, rough" try MAF, IAC, O2 sensor, etc.

It would be much more helpful if you would direct him to the proper thread rather than to scold him for not searching. Your diatribe about searching wastes as much bandwidth a question

 

[1IronMike]

What is your RPM? Maybe there is a vacuum leak somewhere?

 

[pughman]

Your diatribe about searching wastes as much bandwidth a question

ya, but if they dont know how to search, they will just keep asking things that have been talk'd about over and over and over and over......

leading them to the right post is fine , but they got to learn how to search first

 

[4x4rob]

Your diatribe about searching wastes as much bandwidth a question

ya, but if they dont know how to search, they will just keep asking things that have been talk'd about over and over and over and over......

leading them to the right post is fine , but they got to learn how to search first

We all know how to search. Thats how we got here.

Kudos to the Admin. for cleaning this up.

As for the problem: I don't see a vaccum leak causing a problem, but you can check for a vaccum leak by removing a vaccum line while the engine is idling. If the RPM raises, then you just created a leak so there was not one before.

Since you say the compression is ok, then I don't see a problem with the valves. If an intake valve wasn't closing, it would backfire. If an exhaust valve isn't closing, it would be low on compression and have a misfire. To verify a valve isn't closing and the cyldiner has low compression, pour a couple ounces of oil into the cylinder and recheck the compression. If compression goes up, the problem is the cylinder rings. If compression does not change, a valve is not closing.

Find out which cylinder is missing by removing each fuel injector connector, one at a time, while the engine is running. As you remove the connectors from the injectors, you will hear the engine RPM change. The injectors that you disable which cause the RPMs to change is NOT the cylinder with the misfire. When you find the right one, the engine rpms will NOT change. Once you identify which cylinder is misfiring, it's time to determine if the misfire is caused by fuel or spark. The easiest way to do this is by swapping injectors, coils, wires, or spark plugs with a ones that are known to be good. Before you start swapping things around check the fuel injector connector. Wiggle it while the engine is running to see if that corrects the problem. Another good idea is to clean all the injector connectors with contact cleaner.

If it was low on power (more than normal) without a misfire and considering everything else, I'd look for a restriction in the intake or exhaust. Is the air filter dirty, did you leave a shop rag in the air box, or is there a potato in the exhaust pipe.

What do the plugs look like? Is there evidence the engine is running rich?

Let us know if this happened suddenly or over a period of time.

 

[talincolnlsc]

i sold the truck a year and a half ago to a friend and he blew the trans so it sat for a year and he basically gave it back to me so i put a trans in it and it ran like this. it ran like new before it sat so i replaced the plugs wires coil pack, checked compression(all checked about 160) checked fuel pressure(35 psi) checked timing(10 degrees)pulled 1 plug wire at a time and all seemed to make the same difference. the plugs are new and they are covered in carbon already. i just want to get this figured out so i can install my 5.5 inch lift and my 35's and out wheel my freinds jeeps.thanks to everyone who is trying to help fix this problem.also took air filter out still ran the same then took the air tube off and ran the same.

 

[4x4rob]

i sold the truck a year and a half ago to a friend and he blew the trans so it sat for a year and he basically gave it back to me so i put a trans in it and it ran like this. it ran like new before it sat so i replaced the plugs wires coil pack, checked compression(all checked about 160) checked fuel pressure(35 psi) checked timing(10 degrees)pulled 1 plug wire at a time and all seemed to make the same difference. the plugs are new and they are covered in carbon already. i just want to get this figured out so i can install my 5.5 inch lift and my 35's and out wheel my freinds jeeps.thanks to everyone who is trying to help fix this problem.also took air filter out still ran the same then took the air tube off and ran the same.

Since the plugs are new and already covered in carbon, and assuming spark and fuel are ok, you probably have an air problem. Something is keeping the engine from getting enough. Based on the history you described, I'm lead to believe you have a valve sealing problem. However, the good compression is throwing me off. I don't know if this will do any good, but I'm sure you're ready to try just about anything. With the engine running and at operating temperature, run some upper intake/valve cleaner through the engine. I wouldn't advise this, but I use antifreeze or automatic transmission fluid, depending what I have in the garage at the time. I pour some fluid in the cap of the container then disconnect the large vaccum line going to the brake booster to suck the fluid out of the cap. I usually run about 10-12 cap-fulls through the engine.

Is the alternator charging properly? A poorly performing alternator will hurt spark.

Are you sure the engine ran better than this before? I'm wondering if it could be running normal and your memory is tricking you.

I hope you have a heck of a lot of gear for those 35s. I have a 5 spd, 3.73 gears, 33x15.50x15 tires, and I nearly have to get out and push to get it moving.

I'm glad to help. The "Search Police" only prevent new and creative ideas from addressing the same old problems.

 

[AHar_94XLT]

Yes you might have a timing issue so you want to check base timing with the saw connector removed, then in, to verify an advance took place.

I'm thinking a bad crank position sensor might also cause this but it should throw a code.

 

[Bwana Bob]

A leaking diaphragm in the fuel pressure regulator (FPR) will cause fuel to leak into the vacuum line. This makes the engine run very rich, which could account for the carbon fouling on the plugs.

Are you seeing any codes?

Check the wiring harness, too. One or more disconnected sensors will cause the computer to switch to "limp home mode", but this will give you a Check Engine and some codes.


Bob

 

[talincolnlsc]

i just wanted to thank everyone who tryed to help me figure out the problem. it ended up being a bad coil pack. so i returned the new(bad) one to the store and they exchanged it for another one. what are the odds that i ended up with 2 bad coils.i guess you cant trust new parts.