bucking up hills

[iowaranger]

I just bought a 88 ranger 4x4 4inch lift with 31's 5 spd trans. It has a new engine. I had a buddy of mine check the timing its set at 5 with the spout out. I have to change the intake gasket this weekend because its leaking oil out the back side so i didnt have him adjust the timing. Its real doggy up hills runs great on flat land in 5 gear but as soon as i hit a slight hill i have to down shift in 4th. I knocked the cats out tonight seemed a little better. It has a new fuel pump in the tank, new fuel filter and a ton of other new parts.
When i had my 87 it ran like hell with 30's on it and i know the motor i put in it had well over 100,000 miles. Is the timing making it buck or jerk while under a pull? I have checked for vac. leaks and couldnt find any. I'm gonig to check the fuel psi what should it be?

 

[Big Jim M]

hmmm

I just bought a 88 ranger 4x4 4inch lift with 31's 5 spd trans. It has a new engine. I had a buddy of mine check the timing its set at 5 with the spout out. I have to change the intake gasket this weekend because its leaking oil out the back side so i didnt have him adjust the timing. Its real doggy up hills runs great on flat land in 5 gear but as soon as i hit a slight hill i have to down shift in 4th. I knocked the cats out tonight seemed a little better. It has a new fuel pump in the tank, new fuel filter and a ton of other new parts.
When i had my 87 it ran like hell with 30's on it and i know the motor i put in it had well over 100,000 miles. Is the timing making it buck or jerk while under a pull? I have checked for vac. leaks and couldnt find any. I'm gonig to check the fuel psi what should it be?

Bucking and jerking is usually tuneup items. Plugs, wires, dist cap and coil.
It could be you are trying to keep the rpm too low.
The timing should be advanced to the advised setting. You are cheating yourself out of a few badly needed rpm by keeping the static advance where it is.
Big JIm

 

[iowaranger]

When it bucks it only will do it once or twice. Its just a little jerk like hitting a bump. It will also back down on hills in 4th. 5-10mph depending on the wind.
It has new plugs,wires and cap-rotor. I'm not sure what plugs were put in it. I will also adjust the timing. What should the fuel psi be?

 

[87Ranger4me]

I've had this same problem for years on my 87, I have never found a solution. I have replaced every sensor over the years and that has fixed many a problem but never the bucking a kicking going up hill problem. I would love to know a solution to this as my truck runs great in every other respect.

 

[DisturbedMXer8]

Check fuel pressure by unplugging the vacuum line to the FPR. Fuel pressure should be around 35 psi at idle with it plugged in(my ranger sits at about 32) and around 45 with it unplugged, give or take a bit. I believe actual spec is 30-40 and 40-50.

I'd check the cats, if you can. Pull em off and check it out. They might be just old enough to mess with your backpressure and vacuum at higher loads, i.e. hills. Maybe the torque converter as well, I've heard those cause bucking issues when they go bad, though I'm not sure why it'd only do it on hills.

 

[Spitfire1975]

Same thing with both of my 2.9's. Driving me freaking nuts. Trying new knock sensors, as everything else has been changed.

 

[iowaranger]

The other night i knocked the cats out ran a little better. Got home from work thursday night shut it off went to start it to leave again and it was over fueling i pulled the vac. line off the fpr and it was leaking. I replaced it and the intake gaskets this morning. I set the timing. Now it runs 10 times better. I think between timing and fpr it fixed the bucking problem. I replaced the intake gaskets because who ever put the engine together never torqued the intake.

 

[low_five]

i wonder if the knock sensor is detecting knocks and backing the timing down until it finds a better timing. Id try running a few tanks of premium gas and seeing if it makes a difference.