Hello, folks!

I am having trouble with my '86 Ranger with the 2.3L multi-port EFI. Several weeks ago, I started noticing a "hitch" at highway speed, then it stumbled on me a time or two; sometimes it would stumble and then backfire, which makes me think it is getting fuel but losing fire. I replaced the TFI ignition module, since that has given me problems before. The problem got a little more frequent, so I replaced the fuel filter and dropped the tank, looking for water, then in the process cracked the rusty fuel discharge tubing, so had to put a new fuel pump/ sending unit in it.

Today I was looking for wiring harness shorts, etc., started the truck and let it run, turned my back on it, and it just quit. Crank, crank, crank, would not start. I pushed the fuel rail Schraeder valve to see if it had fuel, and just a very brief spurt (less than 1/2 second) came out. Pulled #1 ignition wire and put an old plug on it, jumped the starter solenoid, and it fired right up on three cylinders!

Shut it down and restarted it several times without a hitch. Now I am stumped...

There are connections on the passenger side fender that look as if they may be diagnostic hook-ups- are they?

Any ideas about what could be causing my problem? I could still have a bad high-pressure fuel pump, or maybe the stator assembly could be bad? I put a fuel gauge on the rail, and it ran about 35-40 lbs. the whole time, but it never gave problems while the gauge was attached.

Any input would be very much appreciated! Take care,
Regan

 

Okay, with some more searching on the computer, I found the diagnostic ports, and called a friend with a reader. I got these two codes:

052 PSPS CKT OPEN
018 Tachometer input to PCM signal loss- spout ckt grd

I assume the first is "power steering pressure sensor"? This circuit had been cut before I got the truck 18 years ago, and has never caused a problem.

I assume the spout circuit is the same thing that you pull the plug on to set the timing, but it seems to indicate a ground problem- could that be a stator/ pickup issue, or would it definitely be wiring?

Thanks,
Regan

 

FWIW, when you de-pressure a fuel system, there's not much 'expansion room' to force the pressurized fuel out. In other words, you would not expect a large squirt of fuel out the schrader unless there was a lot of expansion in the fuel lines that was being released.
I had a trailer hitch in my 85, and could get it to go away by plugging the EGR vacuum line. Replacing the EGR valve was not the solution. I had bad plug wires causing misfire under mid speed - 40-50 mph operation. New plug wires cured the problem.
Try doing a fuel pump 'delivery' test. Borrow or buy a gauge with a diverter valve you can open to collect fuel[and release the pressure]. Run the test by starting the engine, so the fuel pump will continue to run, and diverting fuel into a suitable container for X number of seconds. If you don't get ~Y amount of fuel in X seconds, your pump is not delivering enough fuel. I don't have X or Y at my fingertips, but if you can get a cup in 15 seconds, you have more than enough. 60 mph at 15 mpg would mean 1 gallon every 15 minutes, so you can see about a cup every minute [1gal=4qt=8pt=16cups] is an approximation.
tom

 

Thanks, Tom, I appreciate the help- I'll give it a try.

I am on shift at work today, when I get home tomorrow I'll try the fuel pump, maybe check the fuel pump relay. It might also be the EGR valve(?)

Thanks!
Regan

 

first i would replace fuel pump/new fuel filter,next maybe change the pickup coil magnetic hall effect(stator)in the distributor if still thought it was an electrical issue,check ignition coil, check plugs wires ,also a check for clogged up catalytic convertor or muffler they show up with same symptoms on highway speed,,, also replace MAP sensor let us know what it turns out to be, good luck