HELP!!!!!!!!!!! Engine stalls.

[DragHag]

I have a 92 f250 with a non-turbo 7.3 idi and I just upgraded to an electric lift pump. When I crank the truck up it starts and idles like it should. When I rev the engine the engine revs up without a problem, but when the rpms are coming back down the truck stalls out. I checked all of my fuel lines and everything is sealed up there are not any leaks. I had the fuel lines disconnected for a full day before hooking the lines up to the electric pump, could I have air in the fuel system and that is causing the stalling issue? Any help would be greatly appreciated.

Thanks

 

[Compu Doc]

Does the truck start right back up after it stalls?. How many miles does the truck have?. Does it have the original injection pump and injectors?. Have the return lines ever been changed?. How old is the fuel filter?. When was the last time it was changed?.

 

[DragHag]

The engine starts right back without a miss. The truck has 292,000 miles. The fuel filter is new, new braided return lines and o-rings. The truck has the original injector pump and injectors. The truck did not have this problem before a changed the lift pump.

 

[flareside_thun]

Have you run a fuel conditioner in the tank recently such as Howe's or Diesel Kleen? Sounds like it may be a sticky metering valve in the injector pump... even a quart of ATF dumped in the fuel tank can help.

 

[bghnkinf350]

I thought someone just had this problem and the return lines were hooked up wrong. Did you even disconnect any of the lines?

 

[Petri317]

Have you run a fuel conditioner in the tank recently such as Howe's or Diesel Kleen? Sounds like it may be a sticky metering valve in the injector pump... even a quart of ATF dumped in the fuel tank can help.

+1. When I first bought my truck it did the same thing; a hefty dose of Diesel Kleen in the tank and Mercon ATF in the fuel filter cleared out whatever gunk had been clogging the metering valve.

 

[DragHag]

I run the diesel additive that is sold at Wal-Mart it is in the white bottle. I believe the name of the treatment is Power Services Diesel Fuel Supplement + Cetane. I use it on every fill-up. When the manual lift pump was on the engine a didn't have this symptom. The truck was only down for a couple of days, would the metering valve gunk up in that short of a time?

Thank You

 

[smolkin]

Although I am not an expert on IP internals, from what I understand there are some very small passages for the metering valve and any debris entering the IP is likely to get stuck there. I've had crap in my IP metering valve since my old water separator blew up. Heavy doses of DieselKleen in the gray bottle will usually unstick it after a few hours of driving. Strangely enough, I've noticed that B100 also fixes the problem, like night and day. Maybe it is the lubricity or the fact it's slightly thicker than dino...anyway, try 3X the normal additive of your choice. If nothing seems to help, it may be time for a rebuild/replacement of the old IP. The guys at the Stanadyne dealer here tell me that just getting the IP "cleaned" necessitates a complete teardown and recalibration anyway.

 

[Compu Doc]

The engine starts right back without a miss. The truck has 292,000 miles. The fuel filter is new, new braided return lines and o-rings. The truck has the original injector pump and injectors. The truck did not have this problem before a changed the lift pump.

What brand and model electric pump did you put on. Perhaps their is not enough PSI on the pump. Also with 292K miles on the original IP and injectors you should start putting money away to replace them.

 

[DragHag]

I installed a facet dura-lift pump.

 

[Compu Doc]

The pump that you installed has 11.5PSI of pressure. Perhaps that is to much?. I think these trucks require 7PSI.

 

[icanfixall]

Sounds odd. My thoughts are the change of supply pumps has caused the really worn injection pump to finally give up. Running the fuel treatment in every tank full is a great thing to be doing. Might try removing the fuel filter. Pour out the diesel and refill with atf. Reinstall it and run for about 3 minutes. Shut down and let it cook overnite. tomorrow run it like you stole it. If anything is hanging around the metering valves it will be gone. The new pump pressure may just be too high but I really don't know what your line pressure is on that pump. I have a pressure gauge on the injection pump side of my fuel line so I know what the after filter reading is. Its usually 6 to 8 lbs with my carrier electric pump.

 

[93cc7.3]

mine did the same thing after a badly filtered dose of wmo and the addition of an eletric lift pump i took the feed line off the lift pump a blew a decent amount of shop air threw the line with the fuel tank caps off switched the fuel selector and did the same thing after that never had that problem again ...... mine did EXACTLY what yours is doing and i have the lift pump gen lighting sells

 

[DragHag]

Tomorrow I'm going to buy some Diesel Kleen and ATF fluid. I'll Give the truck a good treatment. I'll keep everyone updated and I'll post some pictures of my setup.

 

[tractorman86]

Where in tn are you from?