IDI out of fuel

[adamsanders]

Hello, first time poster here. Last week I bought a 1991 F250 7.3L. It needed a few odds n ends like glow plugs and an alternator but otherwise ran good. I took it out on Saturday and noticed what felt like a small miss. I would stop, the idle would fluctuate up and down and then it would recover. It done this several times and then finally just died and wouldn't start back. I noticed my fuel gauge was at about 1/8 of a tank and after doing some reading, I think I might have ran out of fuel. I am completely new to diesels so instead of adding fuel and bleeding at the filter, I removed the filter and turned the engine over to see if fuel would come out at the filter. It didn't, but I'm not sure it would anyways. Also, I realized that I introduced an enourmous amount of air. I've tried bleeding at the Schrader valve with the filter full while cranking but I'm not getting any fuel out. Any suggestions? Also does this sound like a simple case of air in lines or the lift pump failing? Thanks.

 

[OLDBULL8]

When this falls off or simply deteriorates (see pic.), you run out of fuel, normally its at about a 1/4 tank. There is one in each tank. You have to drop the tanks to replace. Check prices on ebay and from dealer.
Fill it to at least 1/2 tank.
Gonna take a lot of cranking to get all the air out and fuel to the injectors.
Only crank for 20 seconds, let the starter cool for 2 minutes or you'll be changing it.
Keep a battery charger on the batteries. Takes two days to charge them up full at 10 - 15 Amps charging.
Get a remote starter button, there cheap, so you can keep bleeding air at the filter Schrader valve.

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[junk]

Couple things here. Purging these engines cold using the starter is a pain. It's easy to burn up a starter this way. - What bill said.

If you haven't already, fill the filter either with diesel, Diesel additive, or ATF in the fuel filter and put it back on. That way the filter is full of fuel. - looks like you might have done this.

To verify you're getting fuel from fuel pump break loose the fitting at the top of the fuel filter housing from the fuel transfer pump. The pump on the engine block side. Turn over the truck and see if you get fuel there. If you get fuel there continue trying to get it through the injection pump. If no fuel there work on it till you get fuel there. The transfer pumps are pretty cheap so if there's any question replace it. I do stay away from the airtex ones.

So if you're getting fuel at the filter and the filters full then crack some injector lines loose to help purge air there.

Lastly dump at least 5 gallons of clean diesel in the fuel tank 10 would be better. Rule out any supply issues.

My experience is these prime up reasonably well. So if it seems like it's really fighting you I'd suspect a bad transfer(lift) pump.

Good luck.

 

[adamsanders]

Ok guys, a little update. I started the day with two fresh batteries. I pulled the metal inlet line to the fuel filter loose and cranked the engine over about 3-4 times at 10-12 seconds each time. Nothing, not even a dribble came out and I feel like it should seeing as how the lift pump is directly below it and nothing in between. Furthermore, I pulled the filter off and poured what was in it out and refilled it with diesel to the brim. I put it back on and reconnected the lines and when I cranked the engine, it hit and ran for maybe 5 seconds before dying. It wouldn't restart. By this time my batteries were getting a little weak and I was stumped so I called it quits. Any ideas? I feel like could be the lift pump but what are the chances it goes out in conjunction with running out of fuel?

 

[IDIBRONCO]

I would think lift pump too. The clue is that the idle would fluctuate at a stop and then the engine died. It may have not run out of fuel. The lift pump just quits pulling fuel from the tank. An easy test is to unhook the rubber line between the frame and the lift pump. Hook another, longer rubber line to the lift pump. Run the other end into a gas can with clean diesel in it. Then crank the engine over to see if it pumps fuel. If not, then your lift pump's bad. By telling you to add some fuel to the tank, they weren't saying that you ran out of fuel in the tank, this is in case the shower head (see oldbull's picture) in your tank broke off. Try this test first.

 

[adamsanders]

Ok, good idea. I will try that tomorrow. Is it possible that the IP is strong enough to run the system by itself as long as it doesn't lose prime and running it out of fuel (if I did) killed the prime and exposed the bad lift pump?

 

[icanfixall]

Welcome to the forum. YOU MUST ADD DIESEL TO THE TANK... Otherwise at 1/8 tank of fuel you will NEVER be able to suck up the fuel.your shower head suction head is broken off in the tanks. The one pictured is what is missing. this is a common issue with our trucks. Easy repair is NEVER allow the tank level reach the last 1/4 tank of fuel. Next easy repair is remove the suction from the tanks and add 3 or 4 inches of fuel hose and 2 hose clamps. Plenty of mentions how to do this. Sadly the rear tank needs to be removed to reach the suction line slash level indicator for that tank. the front tank can be removed easy.Just reach up under the bed. Remove the electrical plug. Then the supply line and the return line. then knock loose the retainer ring and lift out the level suction indicator. Watch for the locating pin in the seal area and the gasket when it goes back together.

 

[adamsanders]

Sorry for any confusion. I did add 5 gallons of diesel as soon as I realized that I possibly had ran out of fuel. I agree, I will just not go below 1/4 tank for the time being. I just wanna get back to driving it ASAP

 

[icanfixall]

Any chance this has a standard trans? If so push or tow it to get the engine turning over quicker to purge out the air. It saves the batteries and the starter.

 

[adamsanders]

It is a manual transmission. However, it is at the top of a large hill now (my driveway) and I'm afraid if I roll crank it down, it won't crank and I'll have no way of getting it back up to my garage haha. If it comes down to it, I will probably have access to a truck that can just pull it around this weekend but I'd like to get it running before if possible.

 

[pndwind]

Add electric fuel pump, fill tank with fuel, fill fuel filter with clean diesel or atf, prime to Schrader valve, Crack injector lines, prime to injectors closing each line as it gets fuel.

 

[hoodshauler]

Since you said there was no fuel coming out of the line from the lift pump i would replace your lift pump refill your filter again and give it another try. And maybe even put another 5 gallons of fuel in the tank for good measure!

 

[OLDBULL8]

Just adding 5 gallons is not enough, five gallons only brings the tank up to 1/4 full. After adding, wait a few minutes for any tank debris to settle so you don't get any in the fuel selector valve. Use the front tank to do all the above.

 

[snicklas]

Agreed with the last 2 posts. Make sure there is at least a half tank (10+ gallons) in the tank you are working from. We just fixed the fuel pick up on the 92 in my signature. The end of the tube is at approximately the 1/4 level, but you could start to feel chugging and lurches around the 1/2 tank level due to the fuel moving around. If the truck isn't sitting level where it is now, you may still not have enough fuel in the tank.

Also, if/when you enter the tank to fix the pick up, I would suggest draining the tank (a kerosene pump works extremely well through the now open sender hole) and fishing all the parts out of the tank. When you think you have everything out, check it again..... If anything is still left in the tank from the shower head, it WILL find its way to the tube that now reaches the bottom of the tank and cause fuel supply problems. Ask how I know...... that's Thursday's project, gotta pop the bed loose and get in there again......... Thought everything was out, but we missed something. We also didn't drain the tank.... so something may have hid in the fuel......

 

[adamsanders]

Ok, I replaced the lift pump and reconnected the line back to the tank. I cranked the engine over 2-3 times and I am not getting anything out of the lift pump! I'm fairly certain I put it in under the cam as directed but it's very difficult to see. I listened close and turned the engine over with a momentary button for the first time and i felt a little suction on my finger at the inlet. How do I get fuel up to the pump? Before I reconnected the lines I blew compressed air from the tank and fuel came out at the lift pump end.