i picked up a new fuel filter today. what i did was i turned the truck off (its an 88 ranger with the 2.9l and its 4x4) and then i took off the hose closest to the motor and let it drain, then i took off the opposite and did the same. that it, i did not disconnect the battery or pull a fuse out or relieve the fuel pressure or anything. i put the new filter on and went to start it and all the truck does is crank. i turned the key on so the fuel pump would kick on multiple times but it still wont start. Help! i need the truck to go ice fishin tomorrow morning!

 

see if it catches with ether sprayed in the air box.
remove new filter and check for flow arrow

 

You might want to get a fuel pressure guage and see what you've got. The pump may not be building sufficient pressure.

 

I would check for fuel pressure near the fuel pressure regulator. The owners manual for older models suggests you may have to cycle the switch 10 times to get the fuel primed up to the injectors. I am thinking you have EFI on a '88 rather than the 2-barrel carb. Are you sure there is enough in the tank for the pump to reach? If you are parked on a slope, it may be the fuel pickup is not submerged. I have had that happen once with an engine let idle along side a freeway, and the fuel all went 'downhill', and the engine died and would not start until we added a couple gallons.
tom

 

Did you have fuel pressure & was it was running before the filter change???? If so, I'm thinking you have a slug of air in the fuel lines between the filter & injectors. So maybe consider using a fuel pressure gauge with a drain valve & hose into a catch container, to open the fuel rail schrader valve test port, while you turn the ignition on & off to cycle the fuel pumps on & thus burp the fuel line & fuel rail of air. Cycle the ignition until you get fuel in your catch container.

Then use the fuel pressure gauge to check your static & running fuel pressure.

If it wasn't running before the filter change, did it happen after some event????
Let us know how it goes.

 

ok, i sprayed some starter fluid in the 2 intake ports, and nothing happened, it might just be old fluid though, it didn't have a cap on it and i no iv had it for a while, i borrowed a fuel pressure tester from work, i hooked it up, bled it for a few seconds, turned the key on. and it didn't move, i cranked the motor and still nothing, so it didn't read any pressure. yes theres enough gas in the tank, its on a level surface and i have over a quarter tank, i added a gallon just to be safe and still nothing. i disconnected the fuel link in front of the inline fuel pump, the one on the rail, and gas came out, i was waiting for it to slow down and eventually turn to a drip to turn the key and see if gas came squirting out but it never stopped flowing so i clamped the hose and put it back on, then i took the hose off the rear of the fuel filter (farthest side from the motor) and no gas came from the filter so i don't think its the filter, and then i had my stepdad turn the key to prime and nothing really came out, then i had him turn it over and a little gas came out. i hooked it back up.
Ok, before i did anything to the truck, i had tested the pressure before, and i got around 40. and it always started. one thing, when i was changing the filter i unbolted the shield attached to the fuel pump on the frame rail to clean stuff it, it was muddy so i just used my fingers and picked mud off, could that have done something? i got back under and wiggled wires and plugs and pushed em in and still nothing. also i still dont think i hear a fuel pump kick on when i turn the key on.

 

When you turn the ignition key from off to run (but don't go to start to crank the engine), the fuel pump/s should run for a couple of seconds to build pressure, then shut off, until the computer senses that the engine is being cranked, it has oil pressure & then it'll turn the fuel pump back on to keep the engine running.

So if you have a dual fuel pump system, (in tank low pressure feed pump, or frame rail high pressure injector feed pump/s not run at all, something electrical is wrong.

So, maybe look under hood in the power distribution box at the fuel pump power relay, wiring to the pump thats not running, or the pump itself, are suspect. Sounds like you've done a wiggle test without joy, so try thumping the pump that doesn't run & see if it'll wake up.

If no joy, use your multimeter to determine if the high pressure pump on the frame rail is getting B+ voltage for a couple of seconds, when your helper turns the ignition to KOEO.

If no voltage to the pump electrical connector, move under hood to the power distribution box & thump the fuel pump power relay & see if it'll wake up.
If no joy, remove the power relay & inspect its pins/sockets for corrosion, bent/broken pins, spread sockets, or try swapping the power relay for a like one not needed to run the engine & see how it goes.

If still no joy, remove the relay & check to see if the computer is sending 12 volts B+ to the relay solenoid pins to have it close its contacts at KOEO & check for B+ at the solenoids switched contact points, to make sure its getting B+ that far to be switched to the fuel pump to make it run.

If you have B+ at the output side of the fuel pump power relay, but not to the pump, check the in cabin inertia switch, to make sure a size 12 shoe hasn't kicked & tripped it!!!!

At KOEO, if your not getting B+ from the computer to have the power relay close it's contacts, something is wrong with the ignition switch, computer power relay, wiring or contacts between the ignition switch & computer, or between the computer & fuel pump power relay, or the computer irself.

So with visual inspections, multimeter voltage tests & thump/wiggle tests, try & narrow down & isolate where the fuel pump power is going missing at KOEO & let us know what you find.

 

ok, i replaced the fuel pump. and let me tell you, it needed it. the filter on it just crumbled between my fingers, and it was all plugged up. so the fuel pump is on and now it runs. but honestly, i think it runs worse. it idles harder and it still backfires at the intake. any suggestions? maybe plugged injectors or something?

 

To me backfire through the intake suggests a sticking open intake valve/s, spark timing problem, crossed plug wires, or mis routed plug wires causing inductive pickup/spark plug firing. Are any of the valves sounding noisy????

 

im not familiar with what a valve sounds like actually, whats it sound like? it does have a lifter knock but its a 2.9l.

 

That lifter knock sound might be a sticking open intake valve, fashion a stethoscope of tubing, hose, broom handle, long screwdriver, one end to your ear, the other end on the noise suspect area & see if you can narrow it down to a specific cyl.

 

Does the RPM Signal come from the CMP Sensor (Camshaft sensor) or CKP (Crankshaft sensor)???

so say if you just had a Bad Oil Pressure sensor the Computer would Not Let the engine Start???


I kinda had the same thing going today changed fuel filters and didnt get truck started again after

I do have fuel Flow as I verified bypulling the Fuel lines apart at the Quick Connections by the Master Brake Cylinder Both return and Supply lines had Flow

 

ok heres an update, when i changed the fuel filter, i must have accidentally moved the hose on the back of it to much because my truck didn't start, what happened was the hose must have knocked around the connections on the inline fuel pump, because one was barely hanging on, so BLADE35, id check the connections on your inline fuel pump. i was told that there was another canister in front of the fuel pump in the tank, so i pulled that canister apart and there wasn't any filter in it it was empty, so i just made 2 new lines and by passed it. and i took it for a drive and its still not running any better. my next suspicion is plugged injectors...so i bought some lucas injector cleaner and put it in the tank and let it cycle while i keep working on it...i highly doubt itl do anything.
Now i talked to the mechanic and he seems to be set firmly on the fact that its not getting enough fuel.. but since the filter is replaced, the pump in the tank is replaced. the canister is bypassed, and the inline fuel pump works.. hes stumped. i mentioned the sticky valves and mismatched spark plug wires and he says that if they weren't on the right plugs then it would be idling very rough. and its not. its just when the trucks put under a load, then it spits out the intake and loses acceleration dramatically and i can't go over 45. also its getting AWFUL mpgs... im stumped!!

 

If the fuel pressure regulator goes bad, it can jam in the hi or low position. Or vary. I would check the diaphragm for rupture, and then check the fuel pressure on the rail at the schraeder{tire valve stem looking thing} valve. You can also check volume delivery by tapping the gauge and catching the relief valve flow over a measured period of time, then do math to determine volume/hr.
A 4.0 in a Aero* went from 18 mpg to ~9 when the regulator died. It only cost something past $100 for another {ugh!}, but the fuel mileage went back up...
tom