I have a 93 explorer that's been causing me grief for quite a while. Original thread is here: https://www.ford-trucks.com/forums/1...when-warm.html

The truck runs like it's got a miss on cold days, but pretty darn well on warm days. On a 15 degree day it never really recovers and runs like garbage. On a 40 degree day it will warm up and start running reasonably well. It runs fine on a 60+ degree day. One oddity is that on a cold day I have ZERO power for several minutes after starting it. Not enough power to get it out of my driveway. RPM looks normal, but nothing at the wheels until it warms up.

I found someone who can read the old OBD1 system and was able to see a lean condition on the left bank. He could see the computer trying to compensate. The fact that it's only showing lean on one bank seem to indicate a vacuum leak to me, but I've had it smoked multiple times and haven't seen an issue.

I've fixed numerous actual problems, but I obviously haven't gotten them all.
New intake manifold gasket - Old one was leaking
New plugs and wires
New Injectors - attempting to clear up the lean bank issue
New Oxygen Sensor - (error code "176 (M) Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control" was correct, the old sensor tested bad)
Fuel Pressure tested good (Had the mechanic do it, I don't recall the actual numbers)
New radiator (unrelated, but the old one had a small leak)
Coolant Temp Sensor tested fine, replaced it anyway with another one that tested fine
MAF sensor tested fine


Any help would be appreciated.

 

Check your PCV valve and hose maybe some loose fitting there.Also spray some carb cleaner around intake while engine is running, listen for idle changes (don't spray too much you don't need a fire) maybe it still has a leak.

 

I checked both of those again, but didn't find anything. Thanks for the reply though.
About the only thing I haven't replaced is the ECM. It may be next.

 

I had the battery disconnected for a while, reconnected it and then the Explorer sat for a few weeks with no attention. It was 18 degrees the other morning and it fired up and ran excellent, no issues at all. So I loaded it up and drove it around. After several hours of driving, and two stop/starts later it was doing the same old lean condition trick.

I'm at a loss. I'm considering putting in a re-manufactured ECM.


I forgot to mention in the first post that I've had the car smoked multiple times looking for leaks, but we never find anything.

 

I put in a remanufactured ECM from A1 Cardone Tuesday afternoon (today is Friday). The air temp for the last three mornings has been 31, 29, and 25 degrees. So far the Explorer is running like a champ. Full power, good idle, excellent startup in the mornings, and no engine codes. I'm just about ready to actually say the ECM was the last problem.

This truck had a few problems when I bought it. The seller was upfront with the symptoms, but I was sure it was just the intake manifold. It turned into a whole list of issues and a finally devolved into shotgunning parts at it until it cleared up.

Intake manifold gasket was leaking and got replaced.
New plugs and wires (Routine)
Timing Chain cover was leaking
New Injectors - attempting to clear up the lean bank issue (probably was unnecessary, but was shotgunning parts at this point)
Dead Oxygen Sensor. Vehicle was throwing error code "176 (M) Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control". The sensor tested bad on that side so I replaced it.
Radiator had a small leak, so it got a new one.
Coolant Temp Sensor tested fine, replaced it anyway with another one that tested fine (Was unnecessary, but was shotgunning parts at this point)
MAF sensor tested fine, replaced it with a new one just to see. Pulled and returned new sensor when there was no change.
Replaced the ECM.

I also replaced the center console and the stereo. Somewhere in the past someone cut up the center console to fit a cd changer in it. None of that was useful, and may not have even worked. So it went out and the console got replaced.
The truck got new headlights because the originals were really yellowed.
New locking ***** for one rear door and the back hatch.

Probably some other small stuff as well. It's been a project.

 

I'm glad she's running better for you.
I'm curious where did you buy the ecm? Link?
Also did it need to be programmed? or was it just a plug and play.
Thank's

 

I bought an A1-Cardone remanufactured ECM from carparts.com. This was my first purchase from carparts.com, I have no complaints.
https://www.carparts.com/engine-cont...rdone/a1785512

I had originally found the ECM on Rock-Auto, but Rock-Auto won't ship to CO anymore. So I used the part number to look it up on Cardone's website and followed their link for retailers.

The ECM is pre-programmed so installation was plug and play. Disconnect battery terminal, remove old ECM, install new ECM, reconnect terminal.

 

Thank's for the info.