Mechanics

F150 IGNITION AND OR FUEL PROBLEM

1993 Ford F-150

1993 Ford F150 V8 Four Wheel Drive 218, k miles

truck was running at idle at stop light, started to forward on green. Truck motored about length of vehicle and died. No restart. Did not have spark when cranking, distribitor bushings wore out so it was replaced, still no spark, replaced coil, no spark, (truck had tuneup less than 3 weeks prev with now plugs, wires dist cap and rotor), rechecked dist. Timing and dead on the money. Replaced the ICM on on fender well, no spark, wiring harness checked with DVM and ohm'd checked resistance was in toloraces listed in book. Replaced ECM, no spark. Changed ignition switch as didnt have continunity as listed.
Out of frustration and because I and grasping at what if's I sprayed fuel into the throttle body and the darned truck fired up and ran until fuel was exhausted, all while still not showing spark at coil, or dist, or at plugs using a continunity test light and a new plug with a ground clip attached. Checked fuel rail, injectors, fuel regulator, and fuel pump pressure indicated was low. Somewhere at this point I started
getting spark,
BUT only at approximately half the cylnders at a time, truck barely runs and fuel is injected into the non firing cylnders to point of plugs are wet with fuel on non firing cylnders.
I have checked resistance on all plug wires, wiring harness, I even purchased a code reader and on KOEO test all systems pass code 111 then a 10 marker code then a 212 code stored in Cont. Mem. Which is loss of diagnostic monitor signal, SPOUT circuit grounded, then a 111 all pass code. I have not been able to keep the truck running long enough to do a KOEO test. I have physically checked all underhood wiring harness for broken/burned/damaged wires, (unwrapped harness's), checked all underhood grounding points, harness/module connectors trying to figue out the problem.
what puzzles me is when it died I had just an hour earlier driven it 35 miles with no problem or any indication of any problem.
THEN as if I were not frustrated enough, after I put a pressure guage on the fuel rail, and noticed drop in pressure of 20# when cranking, replaced both intank fuel pumps and pressure regulator, now holds 53 psi at fuel rail and no drop when cranking and only a small drop when left over night down to 25-30psi.
when I could get engine to run long enough, I pulled the plug wires at the dist cap to try and locate which cylnders were not firing, and it appears that plugs 2, 6, 7 are not firing at all(electrodes are white and dripping with fuel), and remaining plugs are soot black, but no liquid fuel. The only error code is the 212 in cont mem, it has new ICM, ECM, Coil, plugs/wires, dist cap, rotor, distribitor, fuel pumps, ignition switch, fuel filter, and the truck has plenty of gas, and there is no water in fuel system, and wiring harness's checked for shorts or any damaged areas, all to no avail on finding why the truck will not run properly. Do you gentlemen have any ideas to what and or how the spout circuit becomes ungrounded and if so will this remedy the problem, or do you have any ideas on what maybe wrong and how to repair the problem. I am beyond wits end and would have boneyarded it by now if it were not for my new truck is a 6 month old new son, which I gladly made that trade. Thanks for your input in advance. Aubrey

Update: a person would think that with purchasing new parts from Orielly's auto parts a person expects that part to function properly. However when I went back to tracing down the basics of compression, timing and spark, and fuel, I inspected everything. Lo and behold upon inspecting the new distribitor, the metal hall effect cup had 4 of the seperator tines touching the magnetic pickup when it turned. That is where the 212 code was prompted from by the computer. It only took me 13 days of sheer dogged frustrated determination to trace down that the new distribitor was defective. I bent the touching tines to clear and waalaa fired right up and after excess fuel was burned and engine warmed up and cleared sensors, it runs great for 218k miles. And a FYI if you have a 1993 f150 and need a PCM. Don Davis Ford Parts department in Arlingotn Texas informed me that they quit making replacments last year and didnt have a replacement, But he would be happy to sell me one that might or not work for 300-350.00 but if it didnt work there was no returns on electrical parts. I hope this thread helps somebody and thanks for all the response.
Avatar
Aubrey sanders jr
April 13, 2008.



Start by using a " noid" light to see if the injectors on the cylinders with wet plugs are hung open or overfueling.

Tiny
Jack42
Apr 14, 2008.