unplugged the MAF...Better

[tdaward]

Been having power issues with my '93 4.0. As I've read in several old posts, when you cycle the key the power will return. Codes first said O2 sensors. Replaced. Changed the coil pack and MAF sensor after researching the issue...could hurt to change them anyway. Still have the problem...Tonight I changed the plugs and wires (wires have a life-time warrenty, so very cheep to try) and the thing is running even worse. Double, triple, and quadrupal check the wire routing. Then I unplugged the MAF and it ran with more power. It did idle rough but it made it down the road much better unplugged. I'm thinking the MAF is bad.

What's your thought?

 

[sniper141]

The MAF sensor is probably plugged, try and clean it, then replace.

 

[tdaward]

As far as I'm concerned, it's under warrenty so it still belongs to O'Reilly's. I'm not even going to clean it, I've had it less than 2 weeks! If the MAF is bad and you unplug it and the truck runs better, that's the problem, right?

 

[tdaward]

I was farting around in the "Tech" section and found this for fire order...(on the left)



what I have in my Chilton is this....(on the right)



which is correct for a "93....this may explain the real rough idle I now have.

 

[Jspafford]

Unplugging a sensor sends the computer into 'limp' mode and usually reverts it to a certain set of peramiters.. All you've really done is narrowed it down to any sensor, related wiring, or the computer.

 

[tdaward]

After I posted this I looked at the pictures....they are the same! I went to my chilton and got a print out that I got off of "the other site" and it was wrong! Don't know why it would give a MAF code with #5 and #6 wires swapped, but it did.....just drove it around the block and it ran great I'll take it to work and see how it does on the highway...thanks to all who read this and gave or will give input....Nate

 

[tdaward]

Decided to change the MAF anyway, it was under warrenty so it didn't cost me a dime. Runs good once you hit 2300 rpm's + or - a few....Doesn't matter if that's highway speed or in 3rd or lower gears. Vacuum? Doesn't the motor pull more vacuum at a lower RPM?

IDEAS?

 

[tdaward]

Did pull the codes this afternoon and 177 (O2 always rich) came up...

 

[tdaward]

I introduced SeaFoam to the intake manifold through the brake booster line...1/4 can and let it sit for about 30 min. Then another 1/2 can for 1 hr...ran it down the road and fogged the neighborhood for a couple of miles....I think I got it (I'm typing cross fingered) It hasn't ran like that since I took it off the farm where I found it! It even barked the tires in first gear! Man I hope that was it, I'll be SeaFoaming every 6 months or so from now on