98 ranger 2.5 power loss.........sometimes

[my98ranger912]

Just bought it with 230k.its a 2.5 5 speed.i have replaced the plugs, wires, coil closest to fire wall, upper and lower intake gaskets.when i got it only one code for o2 running to lean.i also checked the timing belt and replaced it but while doing so i lined the crank gear dot to the notch and the 2 diamonds for the oil pump but on the cam i couldnt get the triangles perfect.before i started when in nutrual when i quickly hit the gas it would backfire(puff) from the tb.with the timing as close as i could get it(cam sprocket clockwise about 1mm past the mark it would still backfire out the tb so i changed the cam sprocket counter clock wise 1 tooth and the back fire went away.
I still have power loss every once and a while accelerating.if im in 5th and doing 60 and step on gas it takes for ever just to get to 70.
There are no enging lights on but when i take off and rev it high the engine light will come on till i shift.
Anyone have any ideas?

 

[Mark_88]

My first thought would be...don't try to accelerate in OD...it seems like every time I manage to shift into 5th gear I find the engine doesn't like it...so I avoid it and probably haven't used OD for at least two years.

Not sure about newer versions of the engine or even FI versions of it, but I don't think it was meant as a gear to go up in speed...once you've hit highway speeds OD is fine...but if you hit a long hill or want to increase your speed quicker it would be better to simply drop to 4th until you are clear of the speed or hill.

The lights coming on would probably require more thorough diagnostics...like running a scanner while driving...if possible. It may not shoot a code that sticks, but there are probably indications of what is going on...

My impression of the CEL is that it is predominantly for emissions...so something (sensor) is going out or getting a reading that triggers the light...maybe by flooring the pedal in 5th you are trying to feed too much gas for the gear and that would cause a sensor to detect a lean or rich condition depending on where the Throttle was at the time...

Anyway...just rambling mostly...I'm sure someone can put things in proper perspective if they understand the computer better than I do...

 

[HAPPY+RANGER+GUY]

No pending codes in the computer?

Just bought it so don't really know the history......I'm wondering about the timing not being lined up.

Engine light may be indicating misfiring at the higher rpms?

5th gear is an overdrive gear and you do have a four cylinder...hehe just saying.

.

 

[my98ranger912]

No codes coming on in the scanner.if it was the cat converter it would lose power all the time right?

 

[my98ranger912]

P0171 code came up again.

 

[HAPPY+RANGER+GUY]

P0171 code came up again.

Give a quick look at the fuel delivery...fuel filter been changed?

If the fuel is lacking and the computer calls for more fuel and cannot be delivered as requested....you'll get the lean code.

 

[my98ranger912]

Give a quick look at the fuel delivery...fuel filter been changed?

If the fuel is lacking and the computer calls for more fuel and cannot be delivered as requested....you'll get the lean code.

I pulled the ff off and cleaned it.it didnt seem to be dirty.i also started another thread about fuel pressure.i checked it with a tire gauge and read 32psi.not sure if a tire gauge would read right but im gonna try to locate a fuel tester to test it.

 

[Mark_88]

Get a vacuum tester...they can also test fuel pressure...up to a certain limit...mine is carbed so I only need about 7 psi on the fuel so my vacuum tester works fine for that...FI should be upwards of 65 psi depending on year et al...but I recall Adsm08 saying they only need about 40 psi to run properly (not sure what year he was talking about though)...

 

[98singlecab]

i too am getting the 0171 code. 98 ranger 2.5l 5spd. 160k miles.
timing belt done by po. o2 sensor done by po about 6 months.
I sprayed the engine done with carb cleaner, nothing,
made sure the dipstick was properly seated (not sure how that willl throw a lean code but ok).
just changed fuel pump and cleaned the prepump strainer.
replaced airfilter.
the truck does not lack power. i do alot of city driving.
should I take it to a shop that can read live codes??

 

[98singlecab]

just cleaned my MAF and now it seams to lose mpg????
getting ready to change spark plugs. wish there was a video on doing this, this is the first time i've been intimidated by spark plugs in my 25 yrs of working on cars.