I have a 1989 Ranger with the 2.9 engine. The truck runs great when it is first started in the morning or after it has cooled off. After it warms up it will start to miss, lifters make lots more noise and I have a loss of power. 180psi compression +/- 5 cold. When I take it down the highway it misses after it warms, and when I pull up to a stop sign the oil pressure will fluctuate and there is a knock. Fuel Pressure is at 40 psi KOEO, then when started drops to 30 psi. rev it up and it raised to 34psi for a bit then right back down to 30psi. Seems like it isn't getting enough fuel. Suggestions anyone.

I have installed a new fuel filter, tried all the electrical stuff which I swapped out or a running truckm new wires and plugs, yes they are gapped right, can't find any vacuum leaks, no water in the oil or vice versa. Truck doesn't use oil or Water. Tried different distributor, reset timing with plug out.

 

if you have tested all the gizmos and gadet manully to make sure everything is in spec on the eng controlls?
fordfuelinjection.com can walk you threw most of it. as it sounds like your truck run bad once it gets warm and gos in to closed loop.thsi is when most the gizmos are "Working" vs fixed setting....anyway..

sometimes a fuel pump will produce enuff psi, but volume gos away after time, cheap test is to get a glass snapale bottle and see if you have enuff volume to fill its about 3/4 of the way in 30 sec or less.

if you have a vacum gun, you could hook it up to your FPR and check to ake sure the diafram is not leaking, or suck on it and see if you can taste gas real strong.

if you have the gage with the bypass button, stupid simple...if not you culd pull the schrader valve hook up a hose and turn on the key I would think.but I might be wrong..worth a try I guess


the 2.9's and 4.0L's are known to eat up rocker arms, where the pushrod contact the rockers and make for the click click click you hear on a lot of ranger v-6's,but in theroy this would be heard more when cold.

oil pressure, could be a bad or plugged filter, oil pump screen is plugging up, oil pump its self going out, and cam bearings

oil psi readings coming from a real gage or the ford dummy panel?