My truck is shutting off randomly again :(
#1
03-25-2016, 04:38 PM
My truck is shutting off randomly again :(
1997 Chevy Silverado K1500 6.5L S vin
No fuel sock
New ignition switch
Relocated Stanadyne PMD (3-4 years old)
New fuel filter management unit and filter
Measured straight wired lift pump flow=1 L/min
Last week I shut it off after it reaching operating temperature and it refused to start. It wore my batteries down, but I have a charger and a generator in the back of the truck, so I charged the batteries and it started.
I was sitting at a light a few days later and it shut off randomly. I then installed a new fuel filter. It ran okay for a bit.
However today I had some real problems. After installing the new oil lines I drove it around checking for a leak. I drove it about 30 minutes before it just shut off slowing for a stop light. It crunk immediately and then shut off again. It then crunk back up and I drove it gingerly to the parts store. I get there and it is idling fine. I check for air in the FFM and there was none. I checked the lift pump flow and got 1 liter in a minute. I did notice the FFM drain valve stem was leaking when opened a little. It is not leaking when shut tight.
I leave and come to a stop light. Right after coming to a stop the engine surged while my foot was on the brake. Quite honestly it startled me and was very disconcerting. It drove fine for a bit, but as I was slowing for another light it shut off again. Crunk, then shutoff, then crunk and drove for a couple miles.
It cut off at the next light and threatened to not crank. I limp home and sat in the driveway with it idling. I revved it up to 2200 rpm and held it there to see if it would shut off. I also put it in drive and sat there a while idling to see if it would shut off. Nope, ran just fine.
At this point I have no idea what is going on. That surge has me thinking the Injection Pump, but then again it idled no problem. Any ideas?
No fuel sock
New ignition switch
Relocated Stanadyne PMD (3-4 years old)
New fuel filter management unit and filter
Measured straight wired lift pump flow=1 L/min
Last week I shut it off after it reaching operating temperature and it refused to start. It wore my batteries down, but I have a charger and a generator in the back of the truck, so I charged the batteries and it started.
I was sitting at a light a few days later and it shut off randomly. I then installed a new fuel filter. It ran okay for a bit.
However today I had some real problems. After installing the new oil lines I drove it around checking for a leak. I drove it about 30 minutes before it just shut off slowing for a stop light. It crunk immediately and then shut off again. It then crunk back up and I drove it gingerly to the parts store. I get there and it is idling fine. I check for air in the FFM and there was none. I checked the lift pump flow and got 1 liter in a minute. I did notice the FFM drain valve stem was leaking when opened a little. It is not leaking when shut tight.
I leave and come to a stop light. Right after coming to a stop the engine surged while my foot was on the brake. Quite honestly it startled me and was very disconcerting. It drove fine for a bit, but as I was slowing for another light it shut off again. Crunk, then shutoff, then crunk and drove for a couple miles.
It cut off at the next light and threatened to not crank. I limp home and sat in the driveway with it idling. I revved it up to 2200 rpm and held it there to see if it would shut off. I also put it in drive and sat there a while idling to see if it would shut off. Nope, ran just fine.
At this point I have no idea what is going on. That surge has me thinking the Injection Pump, but then again it idled no problem. Any ideas?
#2
03-26-2016, 11:34 PM
#3
03-27-2016, 07:27 AM
#4
03-28-2016, 10:38 AM
Diesel Enthusiast
#5
03-28-2016, 07:26 PM
#6
03-29-2016, 08:34 AM
Diesel Enthusiast
Eliminate OPS yes, but it doesnt eliminate the possibility of a weak, damaged, restricted lift pump, clogged strainer, breach in the suction line or elusive air-ports that open up when the vehicle is parked for extended periods. You assume to much..
IIRC, the OPS is redundant power source on OBD2 models, no need to hot wire the liftpump unless theres something wrong with the lift pump relay circuit or related wiring or....
Its my contention that much of the PMD tales are spawned by undiagnosed long term fuel supply deficiencies that create additional work for the IP's PCM err fatigued PMD..
Engine heat not applicable but it makes for a great tale..
NUTSHELL.. GM PCM and Stanadynes PMD (IP PCM) are both proprietary systems, neither wanting to divulge 'trade secrets' so it left everyone on there own to figure it out.
Theres no short cuts to checking fuel supply pressure, flow or air leaks. And skipping all the electrical voltage/amp test and jumping to end of the rather laborious checks and installing a clear hose on the IP return circuit is the fastest way to a costly misdiagnosis.
All Im sayin'
"If a failure occurs in the operation of the lift pump, the customer may complain about a no-start, stall or low power condition. The injection pump must have a continuous supply of fuel without the presence of excessive air bubble in order to operate correctly."
Fuel System Related Services
Fuel Supply System Check
If the fuel supply system is not delivering enough fuel or air is being drawn into the fuel injection system, driveability could be greatly affected or a "Cranks But Will Not Run" symptom could exist. If another diagnosis indicates, or if the fuel supply system is suspected of not delivering enough fuel or drawing air, the following checks should be performed:
• Make certain that there is sufficient fuel in the tank.
• Check for air leaks or restrictions on the suction side of the fuel lift pump.
• Check for restrictions in the fuel return system.
• Check for leaks at all of the fuel connections from the fuel tank to the injection pump.
• With the engine running, check all of the hoses and the lines for flattening or kinks that would restrict the flow of fuel.
Fuel Lift Pump Flow Check
1. Remove the ECM 1 fuse from the underhood relay center to prevent engine starting.
2. Disconnect the pipe at the lift pump outlet fitting.
3. Install a hose at the lift pump outlet fitting and place a 1 liter (0.946 quart) container at the hose in order to collect fuel.
4. Crank the engine or energize the lift pump and measure the amount of fuel:
• If more than 0.24 liters (½ pint) in 15 seconds, refer to Fuel Lift Pump Pressure Check.
• If less than 0.24 liter (½ pint) in 15 seconds, refer to Fuel Lift Pump Suction Line Check.
Fuel Lift Pump Suction Line Check
1. Remove the fuel tank cap and repeat the Lift Pump Flow Check.
• If the flow is more than 0.24 liter (½ pint) in 15 seconds, replace the defective fuel tank cap.
• If the flow is less than 0.24 liter (½ pint) in 15 seconds, go to the next step.
2. Separate the lift pump suction line from the fuel sender.
3. Connect the suction line to a source of clean fuel by using an additional hose.
4. Repeat the Lift Pump Flow Check.
• If the flow is more than 0.24 liter (½ pint) in 15 seconds, refer to Fuel System Air Leak Check.
• If the flow is less than 0.24 liter (½ pint) in 15 seconds, Go to Step 5.
5. Check the lift pump suction line for a restriction.
• If a restriction exists, repair it and recheck lift pump flow.
• If no restriction exists, replace the lift pump and recheck the lift pump flow. Refer to Fuel Pump Electrical Circuit Diagnosis.
6. Attach the lift pump suction line to the fuel sender.
Fuel Lift Pump Pressure Check
1. Install a tee adapter at the injection pump.
2. Connect a pressure gauge with the dial indication of 0-103 kPa (0 to 15 psi) to the tee adapter.
3. Start the engine and measure the fuel pressure.
• If the fuel pressure is a least 4 psi (27 kPa) continue to step 4.
• If the pressure is less than 4 psi, refer to Fuel Pump Electrical Circuit Diagnosis before replacing the lift pump.
4. Remove the pressure gauge and the tee adapter.
5. Connect the inlet pipe.
6. Clean any fuel spillage.
7. Operate the engine and check for any fuel leaks.
Fuel System Air Leak Check
1. Install a transparent hose between the filter outlet and the injection pump inlet.
2. Start and idle the engine, observing the fuel for air bubbles.
• If air bubbles are not present, stop the engine and Go to Step 7.
• If air bubbles are present, stop the engine and Go to Step 3.
3. Check the lift pump suction line for air leakage.
4. Check the fuel sender for air leakage.
5. Start and run the engine.
6. Observe the fuel for air bubbles.
• If air bubbles are present, stop the engine and recheck Steps 3 and 4.
• If air bubbles are not present, stop the engine and Go to Step 7.
7. Remove the transparent hose and connect the hose of the filter outlet to the injection pump inlet fitting.
8. Disconnect the return hose at the injection pump.
9. Install a transparent hose between the injection pump and the hose of the return line.
10.Start and run the engine.
11. Observe the fuel for air bubbles. (It is normal to see small amounts of bubbles during snap acceleration.)
• If air bubbles are present, replace the injection pump. Refer to Fuel Injection Pump Replacement.
• If air bubbles are not present, Go to Step 12.
12.Stop the engine.
13.Remove the transparent hose and attach the fuel return hose at the injection pump.
14.Clean any fuel spillage.
15.Run the engine to check for fuel leakage.
If it were easy, never ending PMD sales err tales wouldnt be necessary....
FWIW Download all the student handbooks below. Next best thing to having the appropriate service manuals..
Stanadyne Pump Diagnostic Troubleshooting
6.5L DS Pump Diagnostics
6.5L Turbo Diesel Engine Handbook (DB2 pump)- 344pg pdf
6.5L Diesel Electronic Fuel Injection Handbook (OBD1)- 148pg pdf
ASE- 6.5L Diesel EFI Handbook (OBD2)
Stanadyne Model DS Electronic Fuel Injection Pump Operation and Instruction Manual
IIRC, the OPS is redundant power source on OBD2 models, no need to hot wire the liftpump unless theres something wrong with the lift pump relay circuit or related wiring or....
Its my contention that much of the PMD tales are spawned by undiagnosed long term fuel supply deficiencies that create additional work for the IP's PCM err fatigued PMD..
Engine heat not applicable but it makes for a great tale..
NUTSHELL.. GM PCM and Stanadynes PMD (IP PCM) are both proprietary systems, neither wanting to divulge 'trade secrets' so it left everyone on there own to figure it out.
Theres no short cuts to checking fuel supply pressure, flow or air leaks. And skipping all the electrical voltage/amp test and jumping to end of the rather laborious checks and installing a clear hose on the IP return circuit is the fastest way to a costly misdiagnosis.
All Im sayin'
"If a failure occurs in the operation of the lift pump, the customer may complain about a no-start, stall or low power condition. The injection pump must have a continuous supply of fuel without the presence of excessive air bubble in order to operate correctly."
Fuel System Related Services
Fuel Supply System Check
If the fuel supply system is not delivering enough fuel or air is being drawn into the fuel injection system, driveability could be greatly affected or a "Cranks But Will Not Run" symptom could exist. If another diagnosis indicates, or if the fuel supply system is suspected of not delivering enough fuel or drawing air, the following checks should be performed:
• Make certain that there is sufficient fuel in the tank.
• Check for air leaks or restrictions on the suction side of the fuel lift pump.
• Check for restrictions in the fuel return system.
• Check for leaks at all of the fuel connections from the fuel tank to the injection pump.
• With the engine running, check all of the hoses and the lines for flattening or kinks that would restrict the flow of fuel.
Fuel Lift Pump Flow Check
1. Remove the ECM 1 fuse from the underhood relay center to prevent engine starting.
2. Disconnect the pipe at the lift pump outlet fitting.
3. Install a hose at the lift pump outlet fitting and place a 1 liter (0.946 quart) container at the hose in order to collect fuel.
4. Crank the engine or energize the lift pump and measure the amount of fuel:
• If more than 0.24 liters (½ pint) in 15 seconds, refer to Fuel Lift Pump Pressure Check.
• If less than 0.24 liter (½ pint) in 15 seconds, refer to Fuel Lift Pump Suction Line Check.
Fuel Lift Pump Suction Line Check
1. Remove the fuel tank cap and repeat the Lift Pump Flow Check.
• If the flow is more than 0.24 liter (½ pint) in 15 seconds, replace the defective fuel tank cap.
• If the flow is less than 0.24 liter (½ pint) in 15 seconds, go to the next step.
2. Separate the lift pump suction line from the fuel sender.
3. Connect the suction line to a source of clean fuel by using an additional hose.
4. Repeat the Lift Pump Flow Check.
• If the flow is more than 0.24 liter (½ pint) in 15 seconds, refer to Fuel System Air Leak Check.
• If the flow is less than 0.24 liter (½ pint) in 15 seconds, Go to Step 5.
5. Check the lift pump suction line for a restriction.
• If a restriction exists, repair it and recheck lift pump flow.
• If no restriction exists, replace the lift pump and recheck the lift pump flow. Refer to Fuel Pump Electrical Circuit Diagnosis.
6. Attach the lift pump suction line to the fuel sender.
Fuel Lift Pump Pressure Check
1. Install a tee adapter at the injection pump.
2. Connect a pressure gauge with the dial indication of 0-103 kPa (0 to 15 psi) to the tee adapter.
3. Start the engine and measure the fuel pressure.
• If the fuel pressure is a least 4 psi (27 kPa) continue to step 4.
• If the pressure is less than 4 psi, refer to Fuel Pump Electrical Circuit Diagnosis before replacing the lift pump.
4. Remove the pressure gauge and the tee adapter.
5. Connect the inlet pipe.
6. Clean any fuel spillage.
7. Operate the engine and check for any fuel leaks.
Fuel System Air Leak Check
1. Install a transparent hose between the filter outlet and the injection pump inlet.
2. Start and idle the engine, observing the fuel for air bubbles.
• If air bubbles are not present, stop the engine and Go to Step 7.
• If air bubbles are present, stop the engine and Go to Step 3.
3. Check the lift pump suction line for air leakage.
4. Check the fuel sender for air leakage.
5. Start and run the engine.
6. Observe the fuel for air bubbles.
• If air bubbles are present, stop the engine and recheck Steps 3 and 4.
• If air bubbles are not present, stop the engine and Go to Step 7.
7. Remove the transparent hose and connect the hose of the filter outlet to the injection pump inlet fitting.
8. Disconnect the return hose at the injection pump.
9. Install a transparent hose between the injection pump and the hose of the return line.
10.Start and run the engine.
11. Observe the fuel for air bubbles. (It is normal to see small amounts of bubbles during snap acceleration.)
• If air bubbles are present, replace the injection pump. Refer to Fuel Injection Pump Replacement.
• If air bubbles are not present, Go to Step 12.
12.Stop the engine.
13.Remove the transparent hose and attach the fuel return hose at the injection pump.
14.Clean any fuel spillage.
15.Run the engine to check for fuel leakage.
If it were easy, never ending PMD sales err tales wouldnt be necessary....
FWIW Download all the student handbooks below. Next best thing to having the appropriate service manuals..
Stanadyne Pump Diagnostic Troubleshooting
6.5L DS Pump Diagnostics
6.5L Turbo Diesel Engine Handbook (DB2 pump)- 344pg pdf
6.5L Diesel Electronic Fuel Injection Handbook (OBD1)- 148pg pdf
ASE- 6.5L Diesel EFI Handbook (OBD2)
Stanadyne Model DS Electronic Fuel Injection Pump Operation and Instruction Manual
#8
03-30-2016, 05:45 PM
#9
03-30-2016, 08:56 PM
#10
03-31-2016, 06:28 AM
Diesel Enthusiast
FACT IS, NO PMD IS INDESTRUCTIBLE.. They were designed to be serviced ie replaced with the IP but to explain fully requires more effort than I am willing to commit to someone who isnt interested in knowing the truth that may reduce sales commissions..
Flight Systems aka D-Tech PMDs are 2nd rate knock offs based solely on Stanadynes old black PMD.
With GMCorps full cooperation and finacial encouragement, Flight System reversed engineered Stanadyne's proprietary IP PCM err PMD in an attempt to STEAL stanadynes market share at the conclusion of GM's and Stan's contentious 6.5 contract so Stanadyne revised the PMD while making some REAL improvements....
As for the 'Lifetime Warranty' claim, s'it comes with strings and a list of prequalifiers. Best read the fine print. Not transferable either so when the current owner gives up and sells it to the next unsuspecting diesel greeny, the never ending PMD sales err tales lives on..
FACT IS THE PMD WAS NEVER THE PROBLEM ITS INTENTIONALLY MISREPRESENTED AS.. PMD failures are largely due to long term undiagnosed fuel supply system deficiencies that go largely unnoticed by the operator and GMs PCM.
The fuel supply system is NOT monitored by the PCM so its common NOT to find DTCs when s'it starts to break down with age and/or use.
But Im not prepared to give a full report but I will say that I have used more PMDs in my own on-going field test as Flight Systems did to get 'certified' by GMCorp..
Joke...
Flight Systems aka D-Tech PMDs are 2nd rate knock offs based solely on Stanadynes old black PMD.
With GMCorps full cooperation and finacial encouragement, Flight System reversed engineered Stanadyne's proprietary IP PCM err PMD in an attempt to STEAL stanadynes market share at the conclusion of GM's and Stan's contentious 6.5 contract so Stanadyne revised the PMD while making some REAL improvements....
As for the 'Lifetime Warranty' claim, s'it comes with strings and a list of prequalifiers. Best read the fine print. Not transferable either so when the current owner gives up and sells it to the next unsuspecting diesel greeny, the never ending PMD sales err tales lives on..
FACT IS THE PMD WAS NEVER THE PROBLEM ITS INTENTIONALLY MISREPRESENTED AS.. PMD failures are largely due to long term undiagnosed fuel supply system deficiencies that go largely unnoticed by the operator and GMs PCM.
The fuel supply system is NOT monitored by the PCM so its common NOT to find DTCs when s'it starts to break down with age and/or use.
But Im not prepared to give a full report but I will say that I have used more PMDs in my own on-going field test as Flight Systems did to get 'certified' by GMCorp..
Joke...
