BusterXLT
New Member
- Joined
- February 14, 2008
- Messages
- 4
- Reaction score
- 0
- City, State
- Bellingham, Washington
- Year, Model & Trim Level
- '93 XLT
So I was driving home from work a few days ago in my '93 4WD Explorer XLT and halfway home it just started running really rough, whether it was at idle or at 50 mph. Smoothed out some when accelerating to 50, but once there... rough.
I am somewhat mechanically inclined, but no expert. (I appologize for the length of this post.)
Got home, raised the hood, checked for vacuum leaks, even while running. Couldn't see or hear anything obvious. Then I started looking at the posts on this site for a course of action, deciding to focus on the posts about getting the KOEO/CM and KOER codes because the CEL had come on, on the way home.
Yesterday I purchased a fuel pressure gauge, CRC MAF cleaner, and some CRC carb cleaner.
I cleaned off the MAF (didn't look especially dirty), cleaned out the IAC, I think, (that thing at the top of the engine to the right as you face the vehicle from the front... held on by two bolts and has an electrical connection). Let dry, re-assembled, started the vehicle and it seemed to
cure the problem... for a while. A bit later it started running rough again. So, learned how, and played with, getting the codes, checking fuel pressure.
I decided that today I would start cold so that I could post a clear (as possible) picture of what the symptoms are.
I attached the fuel pressure gauge and cleared the codes. At this point the fuel pressure was reading 39-40 psi and holding (I could hear the pump run whenever I turned the key on).
Took readings of KOEO: 111 111 *pause* 1 *pause* 111 111.
Removed the jumper wire, started the engine to warm it up (KOER needs a warmed up engine, right?). Let it run, which the idle needle settles below the 1 on RPM gauge with black between the white '1' and the white needle. Warming up shows no signs of problems until about 8 minutes into the warm up, and the roughness starts. Revved up the engine to try and keep it from running rough and tried to hold it at about 2K rpms with a little success (I didn't know how long it needed to warm up, so my goal was about 10 minutes). During this time the fuel gauge showed about 31 psi, and during the rough idling it would jump around inbetween 30 & 40 (so I think pump and regulator are ok).
Shut off the engine, plugged in the jumper wire and took the KOEO readings:
159 159 *pause* 1 *pause* 157 158 157 158
Started the engine for the KOER codes, CEL flashed 3 times, I pressed and held the brake pedal. I waited for the single CEL flash while the engine ran roughly. Got the flash and goosed the the gas pedal.
KOER codes: 412 116 159 412 116 159.
Noticed black residue on the ground below the exhaust pipe outlet.
I'm thinking the MAF needs replacement, but is there more I could test?
Should I be getting the 116 even after a 10 minute warm up?
The temp gauge on the dash does always seem to read low, never in the normal range. I probably should have replaced this long ago since I am now
understanding how these sensors all rely on each other.
I am somewhat mechanically inclined, but no expert. (I appologize for the length of this post.)
Got home, raised the hood, checked for vacuum leaks, even while running. Couldn't see or hear anything obvious. Then I started looking at the posts on this site for a course of action, deciding to focus on the posts about getting the KOEO/CM and KOER codes because the CEL had come on, on the way home.
Yesterday I purchased a fuel pressure gauge, CRC MAF cleaner, and some CRC carb cleaner.
I cleaned off the MAF (didn't look especially dirty), cleaned out the IAC, I think, (that thing at the top of the engine to the right as you face the vehicle from the front... held on by two bolts and has an electrical connection). Let dry, re-assembled, started the vehicle and it seemed to
cure the problem... for a while. A bit later it started running rough again. So, learned how, and played with, getting the codes, checking fuel pressure.
I decided that today I would start cold so that I could post a clear (as possible) picture of what the symptoms are.
I attached the fuel pressure gauge and cleared the codes. At this point the fuel pressure was reading 39-40 psi and holding (I could hear the pump run whenever I turned the key on).
Took readings of KOEO: 111 111 *pause* 1 *pause* 111 111.
Removed the jumper wire, started the engine to warm it up (KOER needs a warmed up engine, right?). Let it run, which the idle needle settles below the 1 on RPM gauge with black between the white '1' and the white needle. Warming up shows no signs of problems until about 8 minutes into the warm up, and the roughness starts. Revved up the engine to try and keep it from running rough and tried to hold it at about 2K rpms with a little success (I didn't know how long it needed to warm up, so my goal was about 10 minutes). During this time the fuel gauge showed about 31 psi, and during the rough idling it would jump around inbetween 30 & 40 (so I think pump and regulator are ok).
Shut off the engine, plugged in the jumper wire and took the KOEO readings:
159 159 *pause* 1 *pause* 157 158 157 158
Started the engine for the KOER codes, CEL flashed 3 times, I pressed and held the brake pedal. I waited for the single CEL flash while the engine ran roughly. Got the flash and goosed the the gas pedal.
KOER codes: 412 116 159 412 116 159.
Noticed black residue on the ground below the exhaust pipe outlet.
I'm thinking the MAF needs replacement, but is there more I could test?
Should I be getting the 116 even after a 10 minute warm up?
The temp gauge on the dash does always seem to read low, never in the normal range. I probably should have replaced this long ago since I am now
understanding how these sensors all rely on each other.