help poor performance

[rearviewsg]

I have a 94 explorer xlt
and i am having some trouble. I was getting a low voltage mass air flow sensor engine code. I cleaned the air flow sensor and replaced. It didn't do any good. I replaced the MAS and it worked great for about 10 miles and now I'm still having the same problem. It feels like it is loading up while operating on the bottom end at about 30-35 mph or 1200-2200 RPM, almost like it is missing. Any ideas?

 

[410Fortune]

Try swapping the MAS sensor out with a new or known good one. Sounds like it is bad.

Also did you reset the computer memory after cleaning the sensor?

Other things related to MAS/Fuel

Fuel pressure regulator

02 sensors

fuel filter

 

[rearviewsg]

I just put a new one in this morning and let the computer reset for 2 hours and it made things a tiny improvement. but the light still comes on and it still runs like crap.

Dustin

 

[410Fortune]

Check the condition of your #5 spark plug.

Do a search for "lower intake gasket" or "Lower intake bolts"

does it run like crap always, just when it;s warm, or only at idle?


A bad 02 sensor will cause it to feel like it's loading up, but normally that would set an 02 code.

Dirty fuel filter?
Old spark plugs?

Oh and FYI the computer only needs a few seconds to reset. I usually let mine sit disconnected for a few minutes while I drink a beer just for good measure.

 

[aldive]

What trouble code is showing?

 

[rearviewsg]

When i checked the codes before i replaced the maf i was geting codes
116
332
538
536
157
124
There 124 is throtle position higher than expected
157 is maf voltage out of range
and the the other one is a egr valve but it has been replaced the sender for the valve is bad but it doesn't make that much difference because i don't have a cat anyomre
it makes not difference if it is warm or cold
i have replaced my plugs and wires like a month ago.
they looked fine to me.

Dustin

 

[410Fortune]

I do not have my code book with me but you must start with the first code and work your way down, so start with 116.

You can go to Autozone and get a printout of exactly how to trouble shoot each code, in order. Very helpful, free, and it is the same info that would be in the Ford shop manual.......

Best place to start.....Oh and if all this stuff checks out, dont rule out the possibility of a bad computer itself. I spent months trying to diagnose a similar problem, turns out the exhaust shop mig welded on my truck with the key in the on position, sent major voltage spikes through my system and the EEC was toast. $600 later the Ford dealer troubleshooted it. $60 used computer from a junk yard was the solution (very Long story). I didnt think to try replacing the computer, since it was storing codes I figured it must be working, wrong!!! Only part of the computer can fail......not necessarily the whole brain box....

 

[rearviewsg]

Well i did some talking i talked to my old auto shop teacher he informed me that the explorers are realy prone to falty fuel pressure regulator.
he said when the ruber diphram goes bad gas gest by and into the vacume system, which makes sense because when i changed my mas i noticed alot almost gunk buildup in the intake manifold and on the throttle body it was old gas so i am thinking i am goign to do a fuel pressure test and a vacume test in about an hour and a half i will let you guys know what happens.

Thanks