Ongoing no start dilemma

[dflaugh]

Back again needing help from you wonderful TDRers .Our 96 2500 has been mostly sitting for a year now because we can't get this no start problem straightened out. Original problem started with fuel cap problem that allowed dirt into the fuel tank. Tank was removed and cleaned, intake screen was replaced, filter changed, screen at fuel heater cleaned-truck would not start. Next lift pump was replaced, then fuel return hose, then new injectors, still no start. At that point we gave it a blast of ether and it started right up and runs and drives fine, just don't turn it off! Yesterday we replaced both fuel lines from tank all the way to the engine removed the fuel heater, put the bowl back without it. We were certain we had it, got the same result. And no we are not just blasting it indiscriminately with ether, but will start right up with a very small amount. We are at wits end, hope you guys can help! Thanks

 

[dflaugh]

Also forgot to mention-shut off solenoid is working good, and removed OFV and stretched the spring (did not replace). Yesterday when replacing fuel lines we were having trouble with return line wanting to leak at engine end, had to put 2 hose clamps and go very tight. Seemed unusual, I didn't think that line should have much pressure??

 

[GAmes]

I hope you are disconnecting the grid heatrs prior to the ether.

In all that parts throwing time was a fuel pressure gauge thought of? Troubleshooting is a lot easier when one is installed.

There are so many possibilities a member once posted a complete description and troubleshooting. This link is from another forum, but Joe G is famous here too. https://www.cumminsforum.com/threads/joe-gs-fuel-system-writeup.58777/

 

[dflaugh]

Joe G's write up is very detailed and is very helpful. I think we must still have an air leak that is overcome once the truck fires, will start at tank module and work forward .

 

[Ozymandias]

There should be virtually zero pressure on the return line.
Sounds horribly wrong when you need two hose clamps to keep it from popping.
Something is bad there.

Take that off, put a bottle or something behind and try to start the engine without that hose connected, maybe you found the issue.

 

[dflaugh]

Thanks for the input guys-after staring at and thinking on this to much ,fresh input is great! One thing Joe G mentioned was pinching off return line and checking for start. Hoping to try some of this later today-will report back. Thanks again!

 

[tomblue01]

My water drain assembly (with the WIF sensor) at the bottom of the fuel filter caused me much grief by letting air into the fuel system. I replaced it with the Fleetguard one, and it went bad in about 4 years. I've since deleted it!

Geno's sells a fuel filter plug for 15$ for such a delete.

 

[tomblue01]

Oh, I also got sick of those gasketed metal sealing washers for the banjo bolts. Replaced with copper washers, and they work flawlessly.

 

[GAmes]

My water drain assembly (with the WIF sensor) at the bottom of the fuel filter caused me much grief by letting air into the fuel system.

How? The fuel filter is under pressure so if the WIF sensor is faulty it will leak. Air is introduced on the suction side, not the pressure side.

 

[tomblue01]

I can't tell you how, but here's what happened (years ago):
I prepped my truck for a long trip. Part of that preparation was draining 'the water' from the fuel filter. As I went up hills, I began to lose power. I crossed the Appalachians (non-interstate) in 3rd gear barely doing 30mph with my flashers on, hoping that I didn't break completely down on the steep grade. I pulled off the road after cresting the top as soon as a spot became available and couldn't find anything blatantly wrong. She was hard to start right then, but ran okay for a while. Still had some power loss on small hills. Within 80mi somewhere in the hills of KY she bogged out completely and off to the side of the road we coasted. She did not restart this time. I spent the next ~10min or so trying to figure things out. I eventually pushed the manual primer; she barely fired up. While temporary relieved, I drove (with the truck preforming poorly) to the first fuel station I came across and parked. About an hour+ later (*sigh*), I thought about that WIF drain. There was some diesel fuel on my lift pump & starter (I had attached a hose during my maintenance, so the wetness was new). The leak couldn't have been too great, because I hand calculated 22+ mpg's on that specific tank of fuel. Anyway, after cycling the drain lever several times and insuring it was fully seated, I fired her up (forgot to prime on the first attempt!) and continued my trip. I drove the next 300+ miles without incident, including going up the long grades of the national forest in eastern IN that I-64 traverses. Ordered up a new drain assembly the next day.
The only things I messed with at the station in KY were the lift pump primer and the WIF drain assembly. I spent most of my time reading up on possible solutions and staring into the engine bay, lost in various thoughts.
After installing the new drain assembly, I haven't had starting/bogging issues since (well, I did have a loose positive cable connection at a totally separate point in time that caused a click followed by the sound of silence...).
When I noticed my drain assembly with a tiny amount of diesel seepage years later, I deleted it. Didn't feel like taking the chance and didn't like the fact that it began to fail again after just a few years.

 

[GAmes]

It was a fuel leak, "There was some diesel fuel on my lift pump & starter" not an air leak. Big difference.

 

[BigPapa]

There are several threads on TDR about the failing WIF drain on the early 2nd Gen 12-valves. After the 3rd failure on mine I found a Wix that fit but didn’t have the valve. I eventually crossed it to a Baldwin and never ran anything else.

 

[dflaugh]

Finally got a larryB's pressure gauge put on.Showing 0 when cranking-so I'm thinking the new mechanical pump is bad.Shows 10 psi once the truck is running. Mechanic that we know is saying to put a fass,but I'm not sure. The truck did great for 350,000 miles on the oem mechanical pump. Looking for some comment on which way to go. Thanks, Darman

 

[GAmes]

A FASS is a big ticket item. Five times the cost of the stock pump, one/fifth the service life. Have you checked the pressure with the return line to the tank clamped as outlined in Joe G's fuel system write-up?

 

[BigPapa]

I agree with Gary, stay away from aftermarket electric pumps. No need for more than the mechanical pump unless you're racing or pulling with over 500-600HP. Below that, you can't beat the mechanical pump. I also agree with Gary on the return line. This will tell you if you need a new Overflow Valve. Also, make sure your on a fresh fuel filter before looking much further.

 

[dflaugh]

Has a new Larry'Bs overflow valve,went out and pinched off line-after about 20 sec. it jumped up to 45 psi-still did not start.Now I'm not sure what's going on again!

 

[dflaugh]

Sorry- fuel filter was just changed again(third time). The truck fires right up and runs normal with very minute amount of start fluid. Thanks, Darwin

 

[GAmes]

I suggest you go back to Joe G's write-up and study the air leak prior to the lift pump information.

 

[BigPapa]

After re-reading this thread and all you’ve done, I agree with Gary, you have something going on causing the lift pump to lose prime. The fuel supply system on the 2nd Gen 12-valve is really a simple setup, but in my opinion, it just has too many unnecessary parts and places for the to be a leak. When I had the engine out on my swap we removed all that unnecessary stuff and re-plumbed it all and I never had another fuel supply issue.

After you start it with ether and it’s running on it’s own, if you shut it off, will it restart on it’s own immediately?

 

[dflaugh]

It will not restart. Thought I would try and remember everything thats been done. Starting at tank has new pick-up assembly in tank,both fuel lines replaced, pick-up line goes straight to lift pump-then to filter, new overflow valve, new filter(3rd one),new injectors.We did put fuel pressure gauge on top of filter instead of at injection pump. Have 0 psi when cranking, jumped to 45psi when pinching off return line, shows 10 psi after starting with ether. Thanks,dflaugh