911 - truck down and snow coming....

[markrinker]

Truck #2 (below) stalled today as if it were out of fuel. Gauge showed 1/2 tank - truck was topped off as part of futile attempts at restarting.

I arrived on the scene, checked SOL fuse, swapped FSD's, and still had no start. Pulled fuel filter, only 3/4" of fuel in bottom of cylinder, replaced. Cracked bleeder, no fuel was present.

Diagnose and replaced inoperable lift pump - and the fuel filter just for good measure. Start getting fuel at bleeder and filter, truck soon fires off after a few cycles, and runs smooth like a champ after stumbling a bit. I am sure at that point we are out of the woods...

However, as we are putting the plow back on, the truck again begins idling rough, sputters, dies. After restarting, truck stumbles and bucks. Cracked fuel bleeder and got lots of bubbles for 5-10 minutes as truck idled smoothly and normally.

However, if you rev it up, it sounds and behaves like a smallblock gas V8 with a cracked distributor cap or bad plug wires. Will idle fine with an occassional 'hiccup' or 'miss', but will not run under load - just its own weight with plow no trailer. This goes on for over 1 hour with no improvement.

Oil pressure normal, water temp normal, not seeing any bubbles rising in overflow tank. Oil was just changed and is reading a bit overfilled on the stick, but no visible water in coolant - no white smoke at exhaust.

Truck was running normally before this series of unfortunate events. 10-12 operating hours ago, there was an overheating event (due to operator error) and melted return lines on the turbo side. They were replaced. Truck had run normally since - up until it died unexpectedly today. It has not been using coolant.

Ideas? I have not pulled any codes, forgot to check and the truck is 15 miles away at a jobsite. May return tonight to check if any are present.

[ 01-03-2006, 04:27 PM: Message edited by: Mark Rinker ]

[rjschoolcraft]

Sounds like you're getting air in the line somewhere. Have you checked the fuel line from the filter housing to the injection pump?

I assume, since you changed it, that you have confirmed the new lift pump is working. Could it be a bad oil pressure switch? If the switch is bad, the pump will run during the crank cycle, but stop when oil pressure is supposed to take over.

Hope this helps!

[Kennedy]

I'd be looking at the inlet side of the lift pump.

[markrinker]

Hi RJ - thanks for responding.

I looked for any obvious leaks in that area, but was working in the dark with a flashlight. Also compounded by the fuel present from the bleeder, couldn't see if there was a leak present or not.

Where should I concentrate my efforts? Does the line run through the intake manifold, between the intake runners?

If we have developed a leak, that might explain why we lost the prime and exposed the failed (or weak) lift pump.

[markrinker]

Hi JK - we buttoned up the truck and pushed it outside to remount the plow as the Sinclair station (needed their lift) was closing.

By the time we knew there was more trouble, we were working in the slush and in the dark - so we parked it until they reopen at 7AM.

My plan is to first recheck the lift pump installation - maybe we have a cracked line or cross threaded fuel line connection.

I keep reminding myself the truck ran fine until it stopped dead. The bucking/air symptoms were only after the fuel filter and lift pump were changed out.

[Kennedy]

If there is air in the system and pressure that narrows the potential points of entry considerably...

[markrinker]

True that. I'll check in tomorrow after we get it back inside.

#1) Check lift pump fittings

#2) Check fuel filter installation and lines to IP.

Thanks RJ and JK.

[markrinker]

Truck went back on the lift yesterday morning. Sure enough, there was a leak in the fuel line a few inches behind the new lift pump. Probably was rusted nearly through, and broke when the mechanic was installing the new lift pump.

A few minutes and a few feet of fuel line later, we were back in business.

Thanks, JK for the answer!

[landrea]

Just a note,the dealer near me has seen a few rusted thru lines and even a rusted thru fuel sender, so try to wash out the top area of your fuel tank once in a while because we all know what the road salt can do and esp. you guys with salt spreaders mounted on your trucks.

[JohnC]

Right before I traded my '95 in it developed a leak in the line from the tank to the pump. No starting problems, just fuel on the ground. So much for the "vacuum in tank" argument... ;)

I left the cap loose for the last 2 weeks and the leak stopped.