I'm going crazy!!!! A few weeks ago I was running just fine on WVO and when I went to switch back to diesel the truck died within a few seconds. I've been over everything I can think of with the tools I have (limited budget) and I feel like it should start, but no fire! Please Help!!! Here are the details.

Potentially pertinent history:
I ran out of gas a month or so ago. Both fuel gauges don't work. I know running out is a no no, but I messed up. In the process of getting it running again I killed the starter. Replaced that and it fired right up. New starter seemed to crank faster than the old one. Got 2 new batteries (a few months old). Lately I had been noticing the tach doing funny things. It was maxed out when driving down the road at 30mph but clearly the engine was running normal rpms. After warming up a bit it seemed to smooth out, but would still jump around occasionally. Now the tach doesn't move when cranking. Also, the last time it ran well I had a hard time getting it started (5 or 6 cranks, then good to go once running).

What I've tried:
This truck is a hobby for me and I work, "off the grid," every other week so it only gets driven a few times a month. At first I thought there may have still been air in the lines from the initial run out. I cranked and cranked while cracking each line (except for #1). I also tried squirting liquid silicone into air intake to get it to run a little and save some cranking. It would occasionally fire for a few seconds, running real rough, and then die. When it did fire there was no response when pushing pedal to the floor (sounds like a definite fuel problem right?). I've changed the fuel filter (I filled it with diesel) and then bled the lines again. I tried running a hose from IP intake directly to a can of diesel... No start. I disconnected the fuel line into the fuel filter and cranked for 10 seconds. Plenty of fuel. Question: I don't have a pressure gauge, but I assume if I get at least 1/3 pt the lift pump is good. Do I need to test pressure there too? I reconnected that line and did the same test with the line coming out of the fuel filter. Plenty of fuel. Just to cover all the bases I tested all the glow plugs. I did a resistance test with them still in the head and got 0.7 ohms or less on 6 of them. The other two I replaced. I tested voltage at all glow plugs and got about 9.6 at all 8. Glow stays on for about 10 seconds at on first glow. When I had each line cracked I appeared to be putting out plenty of fuel, but I don't have much of a reference. It's more than a few drops though. Does anybody have a good video of what it should look like? I have many of the fuel lines replaced with clear. I have no bubbles that I can see going into the IP. I have cracked and bled the lines quite a few times at this point. I do have a few small bubbles in the return line after each crank. A friend told me this was ok. I'm assuming it comes from when the injector pops open and closed. Question: When retightening the steel injector line on #8 there seems to be a 1/16" gap between the nut and the plastic return line cap. This looks off, but I can't seem to get it any tighter/ don't want to over tighten. I've been seating the nut and then about a 1/4 turn. I tried a bit of wd-40 the threads, worked it back and forth, more wd-40, a bit of brushing, back and forth, and so on. Still stops at same place. Is this normal?

What I'm thinking

It sounds fishy that it died when I switched fuels. I am assuming that the 1/3 pt per 10 second crank tells me I'm getting enough fuel going into the IP. Is this a safe assumption? As I was writing this I just thought about the o-rings in the cap that everybody talks about. I would do the return kit, but with my limited funds I don't want to go buying stuff that I MIGHT not need. If the O-rings are worn could this cause the cap to sit lower, creating the 1/16" gap? Would this cause a not start? I also watched a video where a guy cleaned the check valve on the return line to the IP. Gonna go check the O-rings on the #8 cap and maybe clean the IP return line check valve while hopefully somebody responds!!!! Thanks for reading all this. I tried to be detailed in my first post to avoid too much need for back and forth. I was told when I bought this truck that WVO would eventually kill the IP. I'm hoping that's not the case. How can I test the IP?

 

of frist off hook a gas can to the lift pump not the ip pump if i was u i would add a cheap in line see trew fuel fliter so u can see id it sucking fuel or not

 

We have a great Alt diesel forum here: Bio-diesel, Propane & Alternative Diesel Engine Fuels - Ford Truck Enthusiasts Forums

Try posting in there and you should get the answers you need. My thought's? Since you are running UNHEATED WVO, your IP is most likely shot. Sorry......

 

sorry if things were unclear. Doesn't the 1/3 pt coming out of the lift pump tell me it's working? The WVO is heated 3 times: in the tank, at a designated heated veg filter, and with a veg therm in the line right before it hits the IP. Still working on the #8 return line and the check valve.

 

What year truck?

 

I'm just throwing this out there but if the o-rings were bad that would cause air intrusion.

If you had air intrusion it would be really hard to start.

You said you have clear fuel lines though so that should rule out any air.

I'm just thinking out loud.

I know its a bad word but have you considered a little breath of ether to see if she'll get going? It goes without saying that you don't need much at all and you def need to disable the glow plugs.

 

truck is an early '94. Used a little ether the first time I ran out of gas. Haven't used it since then. I'm new to diesels and I didn't know how bad it was for the engine at first. I've been told liquid silicone is safer. Do I glow the plugs if using silicone? I called around to try to get a injector return line kit and none of the auto stores or even the dealer had one. Is the internet the only place I can get one? When I took the #8 cap off I figured out that I think it was actually pushed down too far on the injector. Not sure how this happened. I've only owned the truck for about 7,000 miles. I'll be outa town for the next week, but I'll be back at it Wednesday the 15th.

 

Ive never understood the whole "ether is voodoo" thing... Diesel engines have been starting on ether for... well a long **** time anyway. If its so bad i wonder why EVERY tractor ive EVER operated (alot) has an ether assist button... Just kill the glow plugs and ether it if you think that will get you going. Easiest way is to grab a 9/16 and just unhook the GP main power wires from the fender starter solenoid.

Sounds like you have fuel past the lift pump, but do you have fuel at the injectors? Crack 1,2 a few or hell all of em open and spin 'er over for a few seconds and see if you have fuel leaking around the injectors. Im suspecting that you do not. Therefor im going to guess fuel shutoff solenoid, or bad IP. Might grab a test light and make sure you have 12v at the IP too.

If its cold there, leave the key on for 20 minutes or so, that will cause the IP to get warm and un-gel anything that might be gelled up in there.

Ive seen what IP guts look like after WVO... no way that stuff is ever goin in my tank.

 

Regarding fuel return lines kit, I got mine at a diesel repair shop, not standard auto parts store. charged me $50CDN.

 

Yea I didn't want to start an ether argument lol, all our 5 ton trucks had an ether assist when I was enlisted

 

Not sure if this has already been answered, but I know that NAPA carries a return line kit for about $100. I was looking at it myself last weekend, but that is a lot of money right now

By the way, welcome to the forum!

 

Just got a kit from The Diesel Store for $46 including shipping. Will be away for a week, but parts should be at my house when I get home. I'll have a week with nothing to do but work on my problem. See y'all in a week.

 

Did you even verify that return caps are your problem? They dont sound like it to me. On top of that, even with air intrusion it will start, its just a bear cat to do so. Also the fact that you have no air in the FF confirms this. This is an IP related problem either directly or indirectly.

 

the engine will run with the return caps off the engine... Air intrusion alone will not keep it from starting,,unless the leak is before the lift pump,,.FSS... verify the fuel shutoff valve is working...try a gas soaked rag held in air intake,,or disconnect the glows,,and try starting fluid...plug the block heater in....

 

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It does sound like fueling issue. I don't think the caps are going to fix it for you. The more I thought about it the more it sounded like the fuel shut off solenoid. Or the IP could have been wiped out but the solenoid is going to be what you want to check and make sure is good first.

When you cracked the injector lines how much fuel came out? Did you do this while cranking?

I've not had to do this personally nor have I seen it done, but I'm assuming you should see a good bit of fuel coming out there since its under a good bit of pressure.