3 Dead Cylinders

[MrQ]

I can't believe it.

My truck is idling rough. I cleaned the IAC, replaced the filter, cleaned the MAF, and I can't get the truck to idle right. It's either at 500rpm or at 800rpm like it can't decide.

I do get a CEL at 15-40mph but after that it goes away and randomly comes back.

I decided to do the old school way of checking for dead cylinders, one plug on the coil pack at a time. I pulled cylinders 1, 2, and 3 no change to the engine. Pulled 6 and 4 and the engine nearly died. I definitely have spark on the passenger cylinders (shock to the middle finger), so what is going on??

 

[reapereviltwin]

Do you have a timing light to check if there is current going from the coil pack to the plugs? Or pull the plugs and check for spark to the plugs the old school way.

 

[MrQ]

Thanks mike! Seems weird, but the best people I know are named Mike...

Anyway, Its hard to get to the rear passenger plug. I really really doubt that the wires are bad. I replaced them last year. The plugs may be the problem. I may have to pull them...

 

[reapereviltwin]

LOL! Mikes are great ain't they. Thanks
This might not tell you what it is, but it will tell what's it's not. The rough idle seems to be a vaccum leak, EGR, PCV.
There's a lot of wrench heads who will be coming in with great info.

 

[safn1949]

Thanks mike! Seems weird, but the best people I know are named Mike...

Anyway, Its hard to get to the rear passenger plug. I really really doubt that the wires are bad. I replaced them last year. The plugs may be the problem. I may have to pull them...

The rear plug isn't bad if you turn the wheels all the way to the left and reach in behind the wheel,better yet take the wheel off and it's right there.Buy a spark checker to test the individual spark.Do a compression check if you have spark there for peace of mind.

 

[Hitchhikingmike]

Uh oh. Will the computer not flash the CEL code number at you? Do you know how to do it?

Spark plugs really don't just die, all modern spark plugs easily last several years or 50k miles at a time, unless they are getting fouled. In that case the plugs are still not the main problem.

A vacuum leak sounds plausible. I know on my cologne engine if I pull a vacuum hose off the rpms will go all over the place.

 

[Hitchhikingmike]

http://www.explorerforum.com/forums/showthread.php?t=255962

 

[Hitchhikingmike]

and

http://www.fordfuelinjection.com/?p=13

Even if the CEL goes back off, the computer will still store the code.

 

[MrQ]

I have a 4 CM codes

157 - Mass Air Flow signal is/was low or grounded - MAF
158 - MAF sensor is/was high or short to power - MAF
172 - Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control
173 - Oxygen sensor not switching - system is or was rich - Single, Right or Rear HO2S - Fuel control

I think 172 and 173 are leftovers from when I ran the engine without the Y-pipe to test the new transmission. But who knows? Next time I see a CEL I'll run the code.

 

[Turdle]

I am looking for a common issue here-and what I come up with is the engine harness.
There are 2 connectors down beside the alternator. fuel injector and 02 sensor wiring are in there.

Also-check the o2 sensor wires-make sure they haven't hit the manifold, or pulled loose at the connector during your transmission work.

 

[Hitchhikingmike]

I am looking for a common issue here-and what I come up with is the engine harness.
There are 2 connectors down beside the alternator. fuel injector and 02 sensor wiring are in there.

Also-check the o2 sensor wires-make sure they haven't hit the manifold, or pulled loose at the connector during your transmission work.

HA! we sorta.... just threw out the O2 connector holder bracket... it was a pain in the arse. Hopefully the connectors haven't worked themselves loose or anything. The wires were pretty taught after transmission installation though.

 

[Turdle]

Figured I would hook these 2 threads up

http://www.explorerforum.com/forums/showthread.php?t=278924

seems like you guys have about the same issue

 

[jd4242]

I have a 4 CM codes

157 - Mass Air Flow signal is/was low or grounded - MAF
158 - MAF sensor is/was high or short to power - MAF
172 - Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control
173 - Oxygen sensor not switching - system is or was rich - Single, Right or Rear HO2S - Fuel control

I think 172 and 173 are leftovers from when I ran the engine without the Y-pipe to test the new transmission. But who knows? Next time I see a CEL I'll run the code.

Leftover?!?! Have you not cleared the ecm after all the cleaning and mods?!also you have a three coil design so two cyc run off one pack.if one goes bad the other goes bad two,so it always will fail in even numbers if its the coil.so if you got three dead cylinders its not the pack unless you just missed one

 

[MrQ]

After the computer throws a CEL and the engine is hot, it refuses to show me the codes. It blinks 5 times and then gives up the ghost. When the engine is relatively cool (aka computer cooled off) it will give me the codes without a problem. Me thinks the computer doth not work.

 

[gmanpaint]

Did you swap the ECM when you did the trans swap? Sorry if it was mentioned already somewhere, I just don't recall off hand if it was.

 

[MrQ]

The 4x4 should use the same computer as the 4x2. There is no difference on the internals of the tranny minus the output shaft.

Guys, I am feeling really depressed about Red. I need some assurance that I am not throwing good money after bad. I really need some advice.

This vehicle has GOT to be reliable. I can't keep jumping into it and wondering whether or not its going to get me out of the driveway, let alone the mile to work. I may need to consider selling Red if these problems keep popping up.

 

[Hitchhikingmike]

In all honestly, I'm afraid you would get too little back if you tried to sell red. You would probaly be out a lot more taking the hit on red by selling it, and purchasing another explorer. Even if you replace your transmission again and just do what it costs to turn off the CELs, it would probably still be more economic to do this than taking the hit by selling red only to take another hit for another ex in prestine mechanical condition.

But that's assuming you have the energy to solve the rest of red's problem, I can't speak to that.

If your just really getting down on red, it may just be worth it to take it to a shop to take care of the engine and see if you can get some quotes about labor to swap the transmission. I'm sure that even the additional expense of these two would still be less in loss then selling red for another ex.

If the transmission really is out, I think you would be hard pressed to find any buyers other than scrap yards or part out places. I think you would take the bigger hit economic wise doing it that way.

Sorry if I sound gloomy, but that's my best advice from a friend.

But this is assuming you wouldn't be able to find reliable working order ex for any less than 2k$, but you may just have some of those in the Houston area, idk.

 

[gmanpaint]

Wheel em, break em, fix em, and repeat. That is what lies ahead if you go the off road route. I consider my rig nothing more than a mild weekend trail rig and it is not cheap to keep it going.

Now I understand your just wanting a reliable rig and do some occasional trail riding here. I do believe these rigs are worth it to keep them going as they will in return get you where it is you need to be. Parts are relatively cheap compared to other makes, and models, and they are in abundance being they are the most manufactured SUV ever made.

A complete drive train can be had for less than a thousand dollars, I cant say that for many other makes. The 1st gen frames are thick and stout and will outlast a few drive trains. If your rig is in great shape inside & out, and needs a drive train, I would keep it and find a complete donor rig for what you need. Rolled rigs can be had for less than $500 and have a perfect drive train in it. I have seen engines with low miles and run perfect for $100, transmissions for $75, Transfer cases for $50, axles for $75, etc...

Point is, if you wait it out, research and make deals, shop like your momma taught your sister, you can have a damn good rig doing what you want for less than another make/model's cost for a set of bumpers.

See you at Smorr with your rig doing level 2's and smiling ear to ear.

 

[KobeJ05]

Guys, I am feeling really depressed about Red. I need some assurance that I am not throwing good money after bad. I really need some advice.

This vehicle has GOT to be reliable. I can't keep jumping into it and wondering whether or not its going to get me out of the driveway, let alone the mile to work. I may need to consider selling Red if these problems keep popping up.

i know how you feel i keep getting the intake manifold gasket fix and its still looseing water. the head gaskets were replaced too one time. but i also found out i have 120 psi compression in each of my cylinders so i may need a new engine soon. theres acouples times i tried to sell it and once i hope back in it i wanna drive it again. anyway im gonna run my motor till it blows the compressions too low on it. but i would just fix your x. i seen your projects.

 

[gwaker]

Last summer my 91 sport started to run rough. One of the cylinders wasn't firing. I checked the plugs, wires just like you are.I switched wires and plugs with the cylinders that did fire to find out if they were bad. turns out it was a fuel injector. You can get to the wires on those make sure they are getting power. Replacing them isn't hard but I would replace all six if thats your problem.