Not sure what to check - Codes 181, 185, 186

[mkd8919]

Hello Everyone,

I have a 92 explorer with 108,000 miles, and I’m having some problems but I’m not sure where to start. I’m not sure if these three problems are related or not, so hopefully someone can point me in the right direction.

1. First, and most prominent, happens everytime I start. When I do a cold start, it seems to idle fine, and I don’t have any problems starting. However, if I then shift in to gear, it will almost always die. Sometimes it runs very poorly for 2-3 seconds, and then seems to run normal. If I “stomp” on the gas 2 or 3 times after it’s started, it won’t die when I shift. I don’t have to rev it up much at all, I basically push the pedal down 2 or 3 times, just long enough that it starts to respond. After starting, I don't have any other problems while driving.

2. When driving at highway speeds ( 60+ mph), The check engine comes on intermittently. There is no change in performance from when the light is on to when it’s off. I would say it’s on at least 45% of the time when driving at highway speed. It never comes on when I drive around town.

3. I just found this the other day. If I floor it, and it downshifts into second, it will rev up to around 4k rpm, which seems to be 60-65mph. It won’t shift up at that point, and just hang there. If I let off the gas until it downshifts, it will then gain speed and get to 75. It does not have this problem in 1st gear.

From my research today, I was able to pull the codes. I got a 539 during KOEO, and then 181, 185, and 186 CM codes. Any ideas? I did notice that the AC was on when I ran the test, if that makes a difference.

 

[murkinstock]

http://www.troublecodes.net/ford/

It looks like your MAF sensor is either dirty or malfunctioning. I would start by cleaning it with MAF sensor cleaner and maybe carefully wiping the wire with a Q-tip.
If I recall correctly, you want all accessories off when you do the tests.
Hope this helps.

Murk

 

[mkd8919]

It took me forever to get ahold of the tamper proof bit but I finally did. I pulled the MAF out and it looked kind of dirty but not terrible. I cleaned it off let it dry for quite awhile and tried it out. I'm still having the same problems as before. It seems like it might be running a little bit better, but I can't tell if it really is or I am just hoping it is. Is it time for a new MAF sensor? Would it be worth it to pick up a used one from the junk yard and see if that makes a difference before spending $70 on a new one?

 

[murkinstock]

You can try and disconnect the battery for about 15 minutes so the PCM loses it's memory. Then plug it back in and cruise around so it can re-learn everything. If that doesn't make a difference then you can try the JY MAF. Make sure they do returns though, just in case it's not your problem.
[MENTION=242785]FR-425[/MENTION] You seem to be good with this kind of stuff! Do you have any other ideas? You know far more than me.

 

[natenkiki2004]

Probably time to replace the O2 sensor (may or may not be the cause but at 108K miles, it's due).

Have you checked for vacuum leaks too?

 

[mkd8919]

Sorry all I don't mean to revive an old thread, but replacing the MAF sensor did the trick for me. I went to the junkyard and checked all the MAF sensors I could find, and bought the one that looked the cleanest and in the best shape, that was an OEM part. Cleaned it with MAF cleaner and put it in. Engine ran noticeably smoother with more power. No more pedal stomp when I start (It's only been two months and I forgot I had to do that...), and I haven't seen a CEL since.