Good morning! As i journey on through rebuilding my late brothers 1993 Ranger, it had sat for a while so i decided to pour some Seafoam into it. It was running horribly and the exhaust smelled bad (like old gas). It began to run extremely bad, no power, would die and then take a LONG time to restart...
I have the bed off currently so i decided to pull the fuel pump and filter and drain the fuel system. Did that and put new filter. reinstalled the pump and no it wont start... It will run with starting fluid, but it;s not pumping fuel?

Any suggestions?

As always - thanks in advance.

 

1993 is OBD1 so you can manually activate fuel pump relay

In 1993 the OBD1 connector should be between Engine fuse box and firewall on drivers side, may be attached to fuse box with a Cap that has "EEC" on it

Connector looks like this: https://www.therangerstation.com/tec...ry/OBD_I.shtml

In the drawing you can see Fuel Pump slot is pointed out
Thats the GROUND for the fuel pump relay
Turn key ON
Use a jumper wire and Ground that slot
You should hear a "click" from the fuel pump relay in the engine fuse box
Fuel pump should now be running, "hummm" from the gas tank

If you don't hear it running then check the Fuel Pump fuse in the engine fuse box, should be a 20amp fuse

If you don't hear the "click" when you ground the relay, then check if the CEL(check engine light) on the dash is ON, it should be when computer is on
If you don't see it then check EEC Fuse in engine fuse box, 30amp

If CEL is on, and it should be if engine started by manually adding fuel, then fuel pump relay may be the problem, pull it out and have a look if there is corrosion on the pins

 

Excellent instructions RonD. Followed them easily. Grounded the pump and heard the hum. let it run for a little bit. pulled off the supply hose and no fuel present in the hose. Sounds like the pump is not pumping enough?
If there was water/moisture present in the fuel, would it create a blockage in the "sock" looking doo-dad ? (similar to old paper filters that would swell when exposed to water)

I turn on the key and hear the hum for a few seconds (as normal) but it's just not building pressure....

should i hold the schraeder valve open on the fuel rail?

I don;t want to just start parts swapping.. I appreciate that you guys are always helpful in diagnosing and more importantly.. Teaching people how to do stuff

 

1993 will have an FPR(fuel pressure regulator) on the engine, it has the Return fuel line on it, and a vacuum line, it will be on the fuel rail, just behind and below alternator on a 4.0l OHV

FPR is a valve with a spring, spring is set for 43psi fuel pressure, at 44psi it is pushed open and lets fuel flow back to gas tank
The vacuum hose is used to stabilize fuel pressure at about 30-35psi when engine is running, idle high vacuum lowers pressure, acceleration low vacuum raises pressure
You can check this vacuum hose for gasoline, if found FPR is bad/leaking

To test FPR you can use pliers on that return hose, so if FPR is not working(stuck open), you would block fuel from flow out and back to the gas tank, you don't want to SMASH the fuel line and break it, so gently squeeze it closed, and see if pressure builds up in the system

 

Again, great detail! Thanks. Pulled the vacuum lines off the distribution block at the back of the intake. Didn;t see or get a strong smell of gas. Will do the FPR test tomorrow or saturday. Thanks again.

 

UPDATE.... I found out the fuel pump was messed up I got it going and the truck started right up. It runs horribly - rough, black smoke, and what can only be described as a "Darth Vader" sound from the intake hose.... It clears up for a minute and then starts the Darth Vader thing again with the other symptoms....
Im thinking FPR....

 

Yes, with fuel pump working check the FPR Vacuum hose again

 

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UPDATE 5/19/20 - Running- albeit roughly at times. I replaced AIC, TPS, coil and wires, (not plugs as i didn't have right sized socket... go figure). Cleaned the MAF and cleaned all electrical connections i could see and get to.
I made my own fuel pressure gauge and attached to the rail - truck fired up immediately and ran smooth and beautiful. Accelerated smoothly though a range of RPMS.
Fuel pressure on my gauge was 32... Squeezed the return and saw no significant difference,,, unplugged vacuum and it jumped to about 38. Reattached vacuum and it dropped to 30.
Without warning it began surging and running roughly - fuel pressure at 28 and holding... it would try to die and pressure would rise to 40 with black smoke out the tailpipe. it would smooth out and run "ok" then repeat the process over and over again...
at least now i am able to give it throttle and keep it running....so i feel like progress has been made and i am zeroing in on the real problem.

any thoughts out there or similar behavior?

 

And FPR's(fuel pressure regulator) vacuum hose is still clear of gasoline?

The black smoke would indicate extra fuel got dumped into the engine, which could be the vacuum hose or a fuel injector is sticking now and then(hard to test for that)

When you pull spark plugs a blacker tip can tell you if that cylinders injector is sticking open

Have you run Seafoam or similar injector cleaner in the gas tank?

 

I had Seafoam'd the fuel just before deciding to drain the tank. In draining the tank there was about an inch or two of the old gas in nooks and crannies that i just couldn't get out without removing the tank. I poured brand new Premium fuel (93 octane) and a bottle of fuel treatment/ water separator along with new fuel filter.
Im wondering if the fuel pump has gone crazy.... I did have to smack it pretty good with a hammer to get it pumping again.

Plugs are for later today as well as checking that vacuum line... too hot right now.

also, how fast should the fuel pressure drop to zero????

You are a godsend.... Many, many thanks...

 

By the way.... I failed to mention (I assumed everyone reads my previous posts....lol) I swapped a M5OD in but left the A4LD harness and spliced in where needed....

THAT may be a game changer.....

also its been about an hour and the fuel pressure is zero on my gauge AND vacuum lines are DRY.

 

Fuel pressure should hold for MONTHS and MONTHS

In your year the FPR and the Check Valve inside the fuel pump hold in the pressure
So assuming no smell of gasoline, so there is no fuel line or injector leaks, then most likely the check valve is bad in fuel pump, its just a one-way flap that lets pump push gas out but when off gas can't flow back into tank
You can cycle key on and off 3 times to build pressure back up for starting, you usually get 10psi per key on/off

Just to check injectors, after shutting off warmed up engine pull off the air tube from the intake and open throttle to smell for gasoline, should be no smell, injectors are cut off with key off and engine RPMs then drop to 0 so any extra fuel smell will get sucked out to exhaust
If you smell gas you may have a leaky injector

No, on the automatic trans software, it can cause idle to hunt now and then, and idle will be higher, 750-800rpm, rather than 650rpm that was manual's warmed up idle

 

UPDATE 5/21/20 ..... Following the suggestions above, did ignition switch 4x... fuel pressure went 0-40. Dropped to around 20 within about 10-15 minutes. Couldn't start the truck due to battery issue. ( I had left the key on yesterday...SMH)
Charged battery and started... ran like crap as before. Tried to put my vacuum gauge on but i think my gauge is bad.... Sheesh, can't catch a break.
let the truck run a bit and shut it off - opened the TB and smelled... No noticeable fuel smell.

I am thinking fuel pump replacement is next realistic option. I didn't want to just start chasing parts, but I think with ya'lls guidance, we pretty much exhausted the low hanging fruit....

I'm going to RockAuto and getting a fuel pump, probably a FPR and might as well get a MAF while I'm. Then short of replacing injectors - the fuel Fuel system will be 99% new.

The reward at the end of this journey is going to be sweet.... This little puzzle is coming together 1 piece at a time!!!

 

UPDATE 5/29/20.... Replaced MAF, fuel pump, and Fuel Pressure regulator. Started and ran beautifully for about two minutes, then began dying immediately after starting... After about 20 times AND having to stop and charge the battery as it was starting to drag a little it started and ran on about 4 cylinders and smelled very rich while puffing a little white smoke intermittently.
Found my correct socket and changed all 6 plugs. Each plug was identical. Black, sooty and smelled of gas - but not wet. Interestingly, #1 plug was only finger tight. Replaced with Autolites, check all caps and wires.

Restarted and it runs like a sewing machine.... smooth.... only at about 2500 RPMS.!!! I unplug the AIC and it drops to normal idle... which i believe means a vacuum leak? See RonD... I pay attention!

Checked all of the vacuum lines at the rear manifold multi-port and couldn't detect anything... Unplugging FPR vacuum did increase idle speed.

I can hear a whistling so i know its a leak... just gotta track it down. I am thinking of getting rid of that weird hard vacuum line for the FPR... the way it plugs into those boots is suspect... One end of mine already has been wrapped in electrical tape before it was shoved in there... Can a regular vacuum line work ok or does it have to be hard?
I know... too many questions and it is 5 o;clock.... time for Bourbon!

ONE LAST THING!!! My fuel gauge reads about a 1/4 tank and when the key is turned on - goes to zero... Bad ground???? Could a weak battery be a culprit if it is not producing enough amps and sucking too much off the alternator?

Thanks to any and all who read this . Have a great evening.

 

You can use regular vacuum hose, the hard lines are cheaper and lay out better when assembling vehicle at the factory

Yes, with key off the spring on fuel gauge needle will make it go to about 1/4

Assuming there is gas in the tank, lol, unlikely to be a ground issue, can be, but would be very last thing on a list for "FORD gas gauge that reads empty"
First on the list is Anti-slosh module
Google: Ranger anti-slosh module

It's on the back side of the instrument cluster, how to bypass seen here: https://www.therangerstation.com/for...o-work.140669/
With cluster out you can test the Yellow/white stripe wire that goes back to sender in the gas tank

Second on the list is the float in the tank has a hole and sank to the bottom
You would need to pull the bed off or back a few feet and pull out the fuel pump assembly, which has the float on it
And at this time you could also test the wires for ground and to gauge