7.3 IDI E350 fuel issue

[will_snyder]

Hello All. long time listener first time caller.

So I have a 1994 E350 that was a former Daytona Speedway infield ambulance. Its my tow vehicle, camper, daily driver.

1994 e350 7.3 idi non turbo E4OD


in January i had a no start issue. sent it to a shop becuase i travel for work now. prior to this job i was a 12 yeah AUDI master tech. so repair knowledge is strong but audi doesnt have 7.3 idi's


long story short i had a duralift pump installed and new fuel line installed with AN fittings. we also pulled the tank and cleaned it and installed a new in tank fuel pickup. this van model only has a single tank. also replaced a new fuel filter. so the mechanical lift pump has been bypassed. and rear diff service performed. i have an E4OD. no idea of miles but the ambulance engine run timer says we are around 3200 hours. all work was done in MAY and i picked it up first of june, last month.

on june 23rd i ran out of fuel. because the new pickup installed i didnt realize where the bottom of the tank was in relation to what the fuel gauge says. E is now 1/16 of the tank not the real E.

recently last 2 weeks the engine would surge right before a gear change while driving 40-60mph. the after a week or so the fuel filter (FF) light would creep on. this past monday 7/6/2026 i was driving to work and the FF would slowly turn on and then back off. on the way home (my commute only being 12 miles) i stopped to fill it up with premium diesel. thinking maybe something is up and its sucking air. thinking maybe the in tank pick up was installed wrong? i put 19 gallons in it. while it was filling i left it idling. it was the first time it started surging while fueling it up. i got in and drove the 10 miles home at 45 mph. i was able to get it into 4th gear but keeping it under 2000 rpm. anytime near 2000 rpm the FF light comes on. and i was worried it would stall and i would have a no start on my hands and then have a 7000+ pound paperweight and a big tow bill.

anyway i made it home. it idled for the next 15 minutes fine. let it sit for a day and started it up last night. starts right up. no white or abnormal smoke from tail pipe once its running. ill get a puff of white or blue or dark grey depending as i have the manual ground bypass for the glow plugs i have to hold on with a temporary on/off switch.



i know that when the FF light comes on it is because something is drawing a vacuum on the fuel system.....right?

i know that with all i have replaced already the only thing in the equation is the DB2 injection pump BUT is this the cause of my issues or am i missing something?



please advise.

thanks in advance.

ps I'm in Orlando Florida
pss I dont know how to resize my picture of my van to add to this post.

 

[will_snyder]

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[Jesus Freak]

Im thinking that the e-pump you got ain't got the umph you need/want....... i think holley red or blacks are the superior option for going electric...... but wait until others chime in....... can you check fuel pressure at the Schrader valve?

P.S..... I think your dodge conversion van was in an episode of Knight Rider called "Good day at White Rock".......

P.P.S.......3 coffees and no breakfast does that to me too......

 

[IDIBRONCO]

Im thinking that the e-pump you got ain't got the umph you need/want....... i think holley red or blacks are the superior option for going electric.

Yes and no. The Duralifts aren't worth the cardboard that's used in the box these days. Older ones were good. New ones aren't. Now for the "no" part. The Holleys aren't much better these days. I installed a brand new Holley blue and it only lasted for a year. Others have had similar luck with theirs, no matter what the color. After that, I gave away my brand new, unopened Holley black. I won't take a chance on them again. Right now, I'm running a pump for a 24v Cummins and it does ok. Just ok. Kansasidi said that he was running a Bosch for a 2nd gen 7.3 PSD on his service truck and it never fell below 6 PSI. That is before he tore up the engine. He was running a Walboro before that and could make the fuel filter light come on after he put a turbo on it. Otherwise, people seem to be having good luck with pumps such as FASS or Airdog. These aren't cheap, but they are probably the way to go.

i know that when the FF light comes on it is because something is drawing a vacuum on the fuel system.....right?

Yes. That thing is your injector pump. They will draw fuel by themselves. If your lift pump can't keep up, you'll eventually have a vacuum at your filter. Take it from my experience. Replace your lift pump NOW. Before you damage your injector pump. It happened to me. It's happened to others. The injector pumps need enough supplied fuel to run and keep them cool.

 

[VanGo]

I will watch your thread it appears that our vans are very similar. I can’t give you any feedback yet as my van is still in the garage.
I read a bit on the various e pumps and avoided the Duralift, however i can tell you going to one of the more quality pumps it is a bit costly.(some may even say overkill). My experience so far just getting gas to the fuel housing and then priming the injectors was quite easy. To my surprise it really did not take much effort to get the van running.

Although that is what I hear about these old engines.

I Do like the learning experience I have gone through. One of my concerns is if I take this on a long trip if I do have a problem are there any shops that will actually work on it. I met the master mechanic at a local ford dealer and wanted to find out if their fleet service would be able to “time” the 7.3 idi and the answer is “no they no longer have the tools required for that engine”

So I think it is best to know the engine and the issues they are known for just to make sure you are on top of things to try to prevent a breakdown on the road.

I need to find someone in Michigan to get this engine timed, until I can get the appropriate tools for the job (not cheap)

 

[IDIBRONCO]

i can tell you going to one of the more quality pumps it is a bit costly.(some may even say overkill).

Yes they are costly. I feel that it's worth the extra cost to know that you're not going to be replacing that pump again soon. In December both times for me. It's a lot like the pumps and injectors. The best bet these days is to buy once and cry once.