94 explorer. engine problem.

[eric keri]

1994 ford explorer 4x4 xlt
150,00 miles
daily driver 50 miles a day
The other day i was on my way home from work, I go up and down hills on a single line road. When i was driving up one of the bigger hills I felt something like the tranny slipping. So i was going very easy on it the rest of the way home.. But the problem got bigger, When i was crusing at 1500rpm and giving a little bit of gas it started to shake...I was still thinking it was the tranny. but it started to feel like it wasn't the engine...Well Im almost home. I tried to get on it to see what happens, REALLY NO POWER. It really doesn't even want to shift gears... SO IM STILL THINKING THE TRANNY untill I HEARD it back firing in the front of the truck like it was in exhuast manifolds...
I knew I had to change the fuel filter.
Today I went out to the store and bought the stuff I need.
Changed
fuel filter
air filter
spark plugs and wire.
pcv valve
The basic things to start off with..

The truck does have a problem with the fuel pump relay in the fuse box, I changed that saturday but drove the truck to work on sunday with out any problems...SUNDAY NIGHT IS WHEN IT STARTED TO HAPPEN.

This problem is really most of the time. But sometimes it will run great.
I changed the coil pack about 3 years ago do to some1 cutting into the ignition module harness and running a wire under the battery that moved and grounded it out...So the coil went bad..
The truck idles fine, not in gear it revs up without really any problem.it's just when it is in gear and trying to go it is slugish, hesitating, no power, sometimes back firing... THERE IS NO CHECK ENGINE LIGHT ON, so that makes even harder to find the problem....I even pulled the MAF wire off when it was running (idleing) changed the way the engine ran and the check engine light came on. plugged it back in ran good (idleing) and the light went off.

------------------SO WHAT DO YOU GUYS THINK IT CAN BE-----------------

[jonmark1985]

backfiring makes me think that you have an ignition problem.. as it lies somewhere with the camshaft or crankshaft posistion sensors.

Thats just my two cents...

[eric keri]

Originally Posted by jonmark1985

backfiring makes me think that you have an ignition problem.. as it lies somewhere with the camshaft or crankshaft posistion sensors.

Thats just my two cents...

Yea i was thinking it to be the TPS only becuase it does idle fine.
shouldn't one of those sensor be picked up by the ECM? and the check engine light go on!

[jonmark1985]

sometimes, i mean its hooked up to the ecm, but it shouldn't always thow a code