sensor fun
 

in my quest to troubleshoot this truck, someone (don't remember if it was here or somewhere else) recommended unhooking the MAF and see if it runs different. After the truck warms up (which is typically when it starts running rough), it seems to smooth out a bit if its just sitting there in Park. The CEL comes on as expected and I've noticed something else, it tends to shift, more like slam into gear. This normal when unhooking a MAF? Also now the airbag light is flashing, but it started that over the weekend prior to me deciding to start unplugging things. This is going to get interesting...

Yes on the tranny shifting. I've seen a bad MAF do that before.

Rich

it will shift like that when its plugged in or unplugged? sometimes it seems to be a bit bumpy shifting while its hooked up, but nothing like this. My back popped while it shifted (MAF unplugged.) :confused:

Therapeutically, I hope? :wink:

If it runs smoother it could be a sign that you need a MAF. The ideal would be to find someone else with a similar truck and swap to check it.

I'll have to do compatibility research, but we also have a '99 Explorer w/ 4.0 SOHC. Probably would be a different part though. There is the neighbor's truck. He's a **** anyway. :nervous:

I talked to a local garage that knows the troubled history of this truck. He said that the sensor itself would not be bad unless the computer started throwing out codes. um, yeah. There has NEVER been a sensor that was getting weak that would give false readings in other words.

Sound like what happened to my buddys new truck...if it is then u need to replace your Throttle Position Sensor....their like 15 bucks....and theres a good chance thats it. Thats what i would do.

24 hour update:

THe truck runs quite smoother. Still a little rough, but no worse than other 4.0's I've had in the past. Still looking for another MAF to swap out with this one as a test. Given they are $250 new, $140 reman, I'm very hesitant to just replace it without knowing this is the smoking gun. I'll run it like this for the rest of the week and then fill up to check gas mileage.

wait r u running your truck with out the maf?

for now, yes.

The Explorer MAF should be the same thing. Give it a try -- the basic aspiration of the two vehicles is about the same.

Update
 

After a few days of driving with the MAF unhooked, I hooked it back up and found something interesting: The CEL didn't go off and the the truck was back to its normal rough running. I took it to AutoZone and they were able to pull a bad MAF code (also said it could be a vacuum or low intake issue). I don't remember the exact code.

This may sound stupid (plz forgive, I'm not a tech) but think the MAF is the smoking gun? I can get a junk yard MAF for about $50, which is much easier on the budget right now than shelling out about $250 for a new one.

have you tryed to clean the MAF sensor?

That was one of the first things I tried when this started last summer. Don't remember what I used, but I read it in a thread here. Haven't got a CEL until I hooked it back up.