Truck won't start

[donhoward]

Usually my truck starts right up and runs great, no problems. But occasionally it will start, run a second or 2 and then die. I've been able to get it started so it didn't leave me stranded by trying several times to start and then give it half pedal. It runs rough for a few seconds and clears. No white smoke, no loss of power when it's running.

Any suggestions?

 

[Tractorat]

I have no credentials here. But I had a similar issue a few years ago. It turned out to be a cracked cap on the top of the fuel tank where the fuel line went in. It got worse until I got it fixed, but never did leave me stranded. I think it was causing it to lose prime

 

[Timd32]

Kinda some random odds and end issues I know of.

If it's a air deal:
Any and all rubber fuel lines. Back to the tank.
Fuel heater delete.
Small rubber elbow line off little heater screen deal.

Fuel filter in general.

The boot deal on the Fuel Shut Off solenoid might not be allowing it to pull up fully on the first try. The boot can come off most of the times.

Possible idle too low? It's checked at operating temperature with A/C on. @GAmes has posted that set up a bunch of times for folks.

The heim joints in the fuel rod set up can become sticky, there is an adjustment for that in the book, possibly 5" at rest I'm not sure on that, it's in the book, that might work with the idle deal above once you check that.

I've never messed with my pump so can't give any advice there.

Never hurts to have good batteries and check the cables and cross over cables just in case to ensure you have great power available at cranking.

Grid heater relays are you seeing the drop in voltage for the wait to start?

Good luck hope you figure it out.

 

[donhoward]

After letting the truck set for a few hours it started right up. Not starting seems to only happen when it's hot. Sometimes it sits for weeks without being started and it always starts right up.

 

[donhoward]

Maybe the fuel shutoff solenoid not holding in the run position?

 

[donhoward]

Kinda some random odds and end issues I know of.

If it's a air deal:
Any and all rubber fuel lines. Back to the tank.
Fuel heater delete.
Small rubber elbow line off little heater screen deal.

Fuel filter in general.

The boot deal on the Fuel Shut Off solenoid might not be allowing it to pull up fully on the first try. The boot can come off most of the times.

Possible idle too low? It's checked at operating temperature with A/C on. @GAmes has posted that set up a bunch of times for folks.

The heim joints in the fuel rod set up can become sticky, there is an adjustment for that in the book, possibly 5" at rest I'm not sure on that, it's in the book, that might work with the idle deal above once you check that.

I've never messed with my pump so can't give any advice there.

Never hurts to have good batteries and check the cables and cross over cables just in case to ensure you have great power available at cranking.
n d
Grid heater relays are you seeing the drop in voltage for the wait to start?

Good luck hope you figure it out.

Don't think its leaking down fuel. It sits for weeks sometimes and starts right up.
Idle is set at 800 with AC on and in drive so that should be good.
Fuel shut off was replaced several years ago and the boot is in good condition.

 

[Timd32]

Found that "Engine dies at idle (Especially when hot)" under the Low Fuel Pressure trouble shooting steps. Kinda a long post.....

L6-359 5.9L DSL Turbo VIN D FI

Low Pressure Fuel System Diagnosis

• Vehicle
• Powertrain Management
• Fuel Delivery and Air Induction
• Testing and Inspection
• Component Tests and General Diagnostics
• Low Pressure Fuel System Diagnosis

LOW PRESSURE FUEL SYSTEM DIAGNOSIS

The Bosch P7100 inline fuel injection pump is very sensitive to fuel supply pressure variations. If this pressure is low or pulsating excessively, it may cause:
- Low rpm miss/instability
- White smoke
- Hard starting
- Engine dies at idle (especially when hot)
- Low power
- Fuel filter cracking (caused by high pressure spikes with restricted overflow valve or fuel return line)

If the preceding symptoms/conditions exist:

1. Check fuel shutoff solenoid adjustment. Improper adjustment could affect fuel delivery in the injection pump. Refer to Fuel Shutdown (Shutoff) Solenoid Removal/installation for adjustment procedures.
2. Visibly check the fuel supply line and fuel return line for kinks, bends or any other damage that would restrict fuel flow.
3. In addition to contaminants or air, restrictions in the fuel supply to the injection pump caused by a clogged or dirty fuel filter can cause problems. A restricted pre-filter screen within the fuel heater may also have the same results. Be sure to clean the pre-filter each time the fuel filter is replaced. Refer to Fuel Heater Removal/installation for pre-filter service procedures.
4. Check fuel transfer (lift) pump supply pressure to the injection pump. Refer to the Fuel Transfer Pump Pressure/Capacity Test.
a. Normal pressures are 17-22 psi at idle and 25-30 psi at rated rpm (2500 rpm) with no load.
b. If supply pressure is low, restrict the fuel return line (pinch off fuel return hose). If pressure returns back to normal or above, the overflow valve must be replaced. Refer to the Fuel Transfer Pump Pressure/Capacity Test.
c. If fuel supply pressure remains low with the fuel return line pinched, the fuel transfer pump must be replaced. Refer to the Fuel Transfer Pump Pressure/Capacity Test.
d. High pressure at idle speed indicates a restriction. Make sure the overflow valve has been installed at the fuel return line (pump outlet) and not at the fuel supply line (pump inlet).
e. Fuel pressure must be checked after each corrective action. Other possible causes can be found in the System Diagnosis section of Engine.

Whenever the fuel injection pump is being replaced or removed for calibration, the overflow valve must stay with the pump. Make sure a new overflow valve is used with a new injection pump and the old (original) overflow valve is returned to the authorized repair facility with the old injection pump.

 

[Timd32]

Just in case, I know you said this was replaced.

NOTE: After replacing the fuel shutdown solenoid, the solenoid shaft length must be checked and if necessary, adjusted.

SOLENOID SHAFT ADJUSTMENT
1. Turn the ignition switch ON.
2. Pull up (by hand) and hold on the solenoid lever. If the solenoid is operating correctly, it should remain in the UP position with the key in the ON position.
3. Take a measurement from the bottom of the solenoid mounting bracket to the top of the injection pump shutdown lever pin.
4. Dimension should be 66.9 mm (2.64 inches).
5. If adjustment is necessary, loosen the shaft locknut and rotate the adjustment nut to attain dimension.