94 explorer running funny - Ford Forums

blylock · 07-29-2007, 05:17

strange problem i cant seem to pinpoint

94 exp, 4.0 sohc, 4x4

idles fine, maybe a tiny bit rough. rpm range good with no load, revs fine. driving though it has no guts, and it will not go over 2500 rpms, bogs out when i stomp on it, max speed of 50mph.

new coil pack (tried 2)
plugs
wires

swapped out the maf sensor, it ran better but still boggy.

fuel pressure perfect throughout load and unloaded engine, idle and key on engine off.

new fuel filter
new air filter

no codes either............

any ideas would be much appreciated

its just funny, idles and revs fine not in gear, even stomping on it, its ok, under load it bogs like a mother...

oh yeah, dropped the pipe before the cat and still no change, except the loudness, so the cats arent clogged either

thanks a ton!

cjshelley · 08-13-2007, 15:36

My '94 does almost the exact same thing - I checked codes and the O2 sensors popped up along with "adaptive fuel limit rich reached," but I'm not sure that's what is causing my problem. I replaced my fuel filter and my throttle position sensor with no change, also I checked my IAC and it checked out. Mine will go on the freeway just fine until I start going up a hill and the motor just gives up and my speed drops to 40 mph. when it's idling and I stomp on it it will not rev unless I GRADUALLY give it gas. if anyone has any suggestions, I'm curious as well!

blylock · 08-15-2007, 04:25

theres a tsb on the thermostat causing problems, i changed it and it runs great. must be telling the motor its still cold when its not, screwing up the fuel/air mixture....hope this helps my friend

cjshelley · 09-03-2007, 13:44

I think I accidentally solved my problem. The thermostat was replaced 6 months ago with one from Schucks so I wouldn't THINK that would be the problem. In the process of attaining trouble codes and using a multimeter to test sensors, I took out my MAF sensor, tested it and it seemed fine... but I CLEANED it. Ever since then, things seem to be running better than it has in a year and a half. There was just a little bit of dirt or something on the resistors in the mass airflow sensors that I wiped off. That's the only thing I can think of, but for now the explorer is in tip top shape (crossing fingers).

LondonGeezer · 09-03-2007, 15:49

Interesting read.. glad to hear its working :)