ljthomason

Hi everyone. Need some feedback from you all. My 93 5.8l f150 4x4 has run propane since the mid 90s. I bought the truck this way. ImI converting back to gas since all the systems were kept in place and I've found them to be operational. I have fuel in the rail at 45lbs and I've cleaned out the rails and injectors. I have no start Mind you, this engine purrred every time it ran for over 256000 miles. What do you think my no gas start could be? I can switch back to propane and it starts. Tell me the obvious, PLEASE!

Steve83

How exactly did you "clean out" the rails & injectors? What happened to the gas in the tank(s) while you were using propane? Put all the truck's details & history into your signature as this caption explains:


(phone app link)

ljthomason

The gas delivery system was taken offline in 93 by a local Ford dealership. The system was dormant until i started plugging them back in. I removed the plenum and cleaned it, along with the throttle body and it was pretty gunked up inside. I put 10 gal gas in it, then jumped the pump and let it run constant for 5min. I checked pressure duringthe run and it varied 45 to 49lbs. I then removed the rails and injectors. I used my micro snake camera to look inside and they were clean. Injectors were capped with deposits. They soaked in gas for 1 week, then I made a harness and squirted carb cleaner while activating the injectors. I then reinstalled the fuel components and began the process of FORD NO START. That's how I cleaned the system. It runs perfect on propane just not gasoline.

Steve83

Inside what?What were clean? Not the injectors, if they were capped with deposits.A harness for what? Squirted cleaner into where? Activated which injectors (all at once, one at a time, or a group)? Did you see them actually open? Did you see the carb cleaner &/or gas actually squirt through any injector? Reinstalled which components?

BE SPECIFIC, detailed, & thorough. If you have photos of what you saw or did, post them. Otherwise, I can't help you.

ljthomason

We'll, Steve, this is where i am at:
**No codes. Only KOEO 111.**
1. Spark at ignition coil. *Used Fluke*
2. Ignition coil has 12V input and signal*Used Fluke*
3. Spark tester on all 8 plug wires has spark.
4. Due to maintenance being long over-due replaced the following:
a. New plugs (AUTOLITE 24)
b. New wires (NAPA 8mm)
c. New complete Duralast Gold distributor
d. New fuel pressure regulator
e. New fuel filter
f. Dropped tank and installed new fuel pump. Cleaned and inspected tank.
5. Checked all relays and found all operational
6. Checked all fuses.

When go for a start, I get no injector signal from wires 58 and 59 on my 60 pin. I have 12V constant with key in ON position on both wires at each injector plug and no pulse during start on either wire. I pulled the ECM and didnt visually see any noticable capacitor leakage or damage. One capacitor was laying at about a 45 degree angle and felt a little too easy to raise up with my finger. Im pretty sure that this is my last step and it has me stumped. I am capable of doing the board soldering, I want your input on your opinion and technical expertise. I need to get my truck back running. Thank you for your time and consideration.

A2Z2 BACK OF BOARD

A2Z2 FRONT OF BOARD

sdmartin65

I do believe the early propane conversion systems required the fuel injectors to operate at a much higher pressure than gasoline, that is why your truck was run as a single fuel system. Try a set of injectors from the wrecking yard, you know how to clean them before install so it shouldn't cost much at all. I'm sure you are aware that some F150's with the 4.9 in the 90's were factory ready for dual fuel, gas and LPG. At the time dual fuel with propane wasn't feasible.

ljthomason

I appreciate your help. That is one possibility I didn't uncover. I realized a few days ago that the reason it was put to propane was for the fact that it was routed through the plenum as aspiration, to fulfill the "will it run on starter fluid" question on a crank-no-start condition.
I have tested all signal components for correct V and found them all within specs. I have, in a nutshell, correct timing, spark, fuel in rail at pressure and no pulse. I replaced the electrolytic caps in the ECM after I judged the 10uF of leaning a little too much and figured the other 2 were just as lazy. Didn't help a single bit. The 5.8 runs on fluid but nothing coming from injectors. I really need to know if my 2 codes, 114 and 116, will cause this. I got the 111 after them so I don't know if they are a cause.
Basically, I am determined to learn about why this is happening and how everything works on my F150. This is my most dependable truck and I need to keep it that way. Any more help is appreciated and valued. Thanks again!