Failing Injection pump?

[Archieb89]

Hey guys. My truck has been having a crank no start with extended driving. It doesn't seem to do it when I let it idle in the driveway even long after it reaches operating temp maybe just a slight hard start if I'd shut it down and fire it back up. But after extended drives, like going to the store and shutting it off and letting it sit for 15-30 mins it will crank but not start. I usually get it to start after the 2nd to 4th time trying to crank it and it'll usually only start with the pedal to the floor. I've read about failing injection pumps and heat soak after long drives. I haven't tried the warm water trick but I'll try it next time it happens. A couple things I've found interesting is evertime it's done it the WTS light doesn't come on the first few times and finally it'll come on and that the time it'll start with the pedal to the floor.

Do these glow plugs go off engine temp? and maybe the temps just still too high for them to come on and it's just a coincidence that the engine and injection pump happens to cool enough for them to operate everytime I get it to start?

It's only stalled on me once the since I've had it. Which is about a month. I've put close to 200 miles on it since I've had it. I drove it to work one morning, its about a 30 min drive about 20 something minutes into the drive it just shut off after taking off from a stop up a hill. I sat there for 5-10 minutes trying to crank it with no luck till I held the accelerator to the floor while cranking go it to start and made it to work. It sat in the parking lot for the 9 hrs I worked when I got back it didn't want to start no matter what, me and a co-worker were just looking it over for anything out of the ordinary and finnally we read about the fss so we messed with those and my co worker held the connector down while I cranked and it fired up. Drove it back home with no problems.

It happened once at the gas station after fueling up. I shut it off to pump some diesel in the tank. And when I got back in it cranked and wouldn't start. So I held the pedal to the floor and tried again and it fired right up. Drove it home no problem.

It happened last night when I went to home depot. Shut it off went in the store about 20 mins came out didn't want to crank. Even with the pedal to the floor. I fiddled with the fss connector but it was all seated already and after a bit i got it to start again with the pedal to the floor

And finally today I went to Walmart. Shut it off went in about 45 mins to 1 hr. Came back out, and crank but no start. This time it really didn't want to start. It was alot hotter outside today then the other day it happened. Even with pedal to the floor it wouldn't start after several attempts, I popped the hood messed with the fss but it was fully seated and with the key on could hear the audible click each time I unplugged and plugged it in. Tried cracking again still wouldn't start. No WTS light came on this whole time. Sitting there not knowing what to do i checked the forums and learned about the warm water trick. Reluctant to try it and possibly damge something after about 5-10 mims I decided to give it one more try before pouring water on the pump. I turned the key on this time the WTS lit then went out as normal. It cranked up and fired little hard start this time but not terrible. As it was idling I noticed a popping/sucking sound that seemed to go with engine ram. I shut it off. Fired it back up. Started right up this time. The popping/sucking sound was quieter this time. I decided to drive it home and on the way the sound completely went away and haven't hear it again. Not really sure what this could be.. it sounded like it was coming from the intake before the turbo but couldn't quite tell, maybe the lift pump or injection pump.

It drove perfectly normal on the way back. good power and good turbo spool, no overheating, and good oil pressure. I'm thinking I just need an injection pump but the thing is is this the only problem I've had with the truck. It idles super smooth and crank and fires right up cold on the first rotation every other time, always makes good power. The only thing I've noticed is a puff of white smoke on start up evertime and a super light whisper at idle and smells like diesel.

Maybe failing lift pump diagram, glow plug system, or air intrusion from somewhere else, or just a failing IP?

Any help or pointer is appreciated

 

[Archieb89]

Another thought I had is, is clicking a for sure sign the FSS is working?

 

[Rocknit4x4]

It seems interesting that you say each time it works the WTS light comes on. Makes me think it’s GP related. How confident are you the GP system is working correctly? Might be a cheaper / easier place to start troubleshooting and confirm that’s working correctly before looking at the pump.

 

[DirtyWood]

A few times, seemingly at random, I've had situations where the WTS light did not illuminate but I was able to crank the engine and start--never with a cold engine though, always at operating temp. Fuses all checked out and wiring looks intact so I checked the harness connector that feeds everything on top of the engine. The connector had some pretty dirty pins on it so after a through cleaning and dielectric greasing I haven't had the problem come back, but of course that could be coincidence too.

 

[Black dawg]

If cranking speed is really good, then yes, this is caused by a worn pump.

Tolerances open up, and with hot/low viscosity fuel, pump internal pressure doesnt get to where it needs to go.

 

[MadMac]

A couple things I've found interesting is evertime it's done it the WTS light doesn't come on the first few times and finally it'll come on and that the time it'll start with the pedal to the floor.

First - Please tell everyone about your truck, put it in the signature part of your member info... I had ideas - until I realized late in your post its a Turbo system, which will be different from my NA 6.9 IDI.

This sounds similar to my long journey to reliability. Two things come to mind: 1) the GP controller is not working correctly. 2) it just isn't getting fuel (some notes about your truck and the weather might help too)

The early 6.9 GP controllers are notorious - a lot of people bypass them if for no other reason than to eliminate the variable. Somewhere in the archives is a description of how to test controllers. If you had a GP related harness short, there isn't that much to trace, but its just not typically the problem - I avoided the testing problem and just replaced the GP Harness entirely. That said, if its anything related to GPs - you should know what is good and what is not. Resistance test the GPs in place and then pull anything which is remotely marginal and bunch test them. Yes, this can be a painful and tedious process. Can't remember the resistance numbers you need to get - but my 6.9 will be different anyway - process and numbers will be in the archives.

When replacing my harness, I also replaced the injector return lines - ergo the 2nd issue fuel & vacuum problems. Before you point at the IP - figure out if the intake side is fully pressurized by the lift pump (on the older IDI's - the shrader valve on the fuel filter assembly). After getting stranded several times just like you were - I discovered there was only one of two bolts connecting my lift pump to the block... Amazing it ran at all - but I also had several vacuum problems and hard morning starts.

I'd say vacuum issues too, but you don't mention hard start problems in the morning - though 200 miles might be enough trips / mornings / weather for a good pattern. Still - getting stranded after warm up indicates more of a vaporization which leads to a fuel starvation problem. If fuel intake is not the problem - then I'd look at vacuum issues. I'm not the best wrench - but I think you'd see other symptoms if you had an IP problem - smoke issues to start.

 

[Archieb89]

First - Please tell everyone about your truck, put it in the signature part of your member info... I had ideas - until I realized late in your post its a Turbo system, which will be different from my NA 6.9 IDI.

This sounds similar to my long journey to reliability. Two things come to mind: 1) the GP controller is not working correctly. 2) it just isn't getting fuel (some notes about your truck and the weather might help too)

The early 6.9 GP controllers are notorious - a lot of people bypass them if for no other reason than to eliminate the variable. Somewhere in the archives is a description of how to test controllers. If you had a GP related harness short, there isn't that much to trace, but its just not typically the problem - I avoided the testing problem and just replaced the GP Harness entirely. That said, if its anything related to GPs - you should know what is good and what is not. Resistance test the GPs in place and then pull anything which is remotely marginal and bunch test them. Yes, this can be a painful and tedious process. Can't remember the resistance numbers you need to get - but my 6.9 will be different anyway - process and numbers will be in the archives.

When replacing my harness, I also replaced the injector return lines - ergo the 2nd issue fuel & vacuum problems. Before you point at the IP - figure out if the intake side is fully pressurized by the lift pump (on the older IDI's - the shrader valve on the fuel filter assembly). After getting stranded several times just like you were - I discovered there was only one of two bolts connecting my lift pump to the block... Amazing it ran at all - but I also had several vacuum problems and hard morning starts.

I'd say vacuum issues too, but you don't mention hard start problems in the morning - though 200 miles might be enough trips / mornings / weather for a good pattern. Still - getting stranded after warm up indicates more of a vaporization which leads to a fuel starvation problem. If fuel intake is not the problem - then I'd look at vacuum issues. I'm not the best wrench - but I think you'd see other symptoms if you had an IP problem - smoke issues to start.

Sorry, I just added it! The weather here in sc has been in the mid 90s and lots of humidity, every time it's happened. The GP controller every once in awhile with key on will click repeatedly. Not every time the key is on but maybe 1 put of 4 key cycles. I'm planning on buying the controller and glowplugs from accurate diesel as well as a new harness. I've only had the truck about a month but most stuff on it looks to be original or was replaced in the early 2000s. One of the return lines that goes from the far back injector on the passenger side to what looks like a check valve and then seems to go back to the tank. Was leaking so I replaced that. I'm planing on replacing the rest as well as injector o rings when I have the time. I dont see anything else leaking but I guess that doesn't mean there's not air intrusion somewhere. And it never starts hard in the morning or even if it's been sitting for more than a day. It always cranks up on the first revolution in the morning. It only gets hard starts after extended drives but not if I just idle it in the driveway and let it get to operating temp. It may start a little harder after idling for a long time but nothing too bad. It always blow a puff of white smoke on startup. And most of the time has a whisp of white smoke at idle from the taillipe that always smells of diesel.

 

[Archieb89]

It seems interesting that you say each time it works the WTS light comes on. Makes me think it’s GP related. How confident are you the GP system is working correctly? Might be a cheaper / easier place to start troubleshooting and confirm that’s working correctly before looking at the pump.

Thats what i found strange but its always still fully warmed up when it happens and i wouldn't think it would need them to fire but im not sure with these motors. And not at all to be honest. I'll have to go out and check resistance of the GPs and read up on how to test the controller.

 

[Archieb89]

A few times, seemingly at random, I've had situations where the WTS light did not illuminate but I was able to crank the engine and start--never with a cold engine though, always at operating temp. Fuses all checked out and wiring looks intact so I checked the harness connector that feeds everything on top of the engine. The connector had some pretty dirty pins on it so after a through cleaning and dielectric greasing I haven't had the problem come back, but of course that could be coincidence too.

I'll have to go check the connectors and maybe clean them if needed.

 

[Archieb89]

If cranking speed is really good, then yes, this is caused by a worn pump.

Tolerances open up, and with hot/low viscosity fuel, pump internal pressure doesnt get to where it needs to go.

Yes cranking speed is always good.

 

[IDIBRONCO]

Yes the glow plugs activation is related to engine temperature. When the coolant reaches about 120*, the glow plugs aren't needed to start the engine. If you don't have cold start issues, that eliminates the air possibilities. Like Madmac said, I'm one of those who just don't trust the 6.9 style controllers at all. I bypass them on my own stuff. In the mid 90s, if the sun has been shining on your hood, your engine should cold start even without glow plugs. That should help with the glow plug Vs. IP questions. Definitely try the water trick the next time it happens. Most people say to use cool or lukewarm water to help cool the IP off quicker. I don't see where warm water would hurt either since it should be at a much lower temperature that your heat soaked IP. If your lift pump diaphragm is bad, you'll probably be able to smell diesel on the oil dipstick. Having the no start issue after driving but not after a long idle time is another clue to point you toward the IP. Heat is a tricky subject that would warrant it's own thread. Just remember that the coolant inside your engine will heat up faster than anything on the outside of the engine. That is especially true of your fuel system because the constant flow of fuel through your IP and injectors is there to keep them cooler. You have to heat up the entire tank of fuel before your IP will get close to being the same temperature as your coolant is. That takes a longer drive and not just idling. That isn't any type of check valve at the rear, driver's side of the engine. It's just a T that lets your excess fuel return to the tank. Lastly, your injectors and IP wear at the same rate internally. It's best if you can replace them as one set instead of just replacing one part or the other. If not, replace one part now and the other part as soon as you can afford it. That's the way to get the best performance out of your engine.

 

[Archieb89]

Yes the glow plugs activation is related to engine temperature. When the coolant reaches about 120*, the glow plugs aren't needed to start the engine. If you don't have cold start issues, that eliminates the air possibilities. Like Madmac said, I'm one of those who just don't trust the 6.9 style controllers at all. I bypass them on my own stuff. In the mid 90s, if the sun has been shining on your hood, your engine should cold start even without glow plugs. That should help with the glow plug Vs. IP questions. Definitely try the water trick the next time it happens. Most people say to use cool or lukewarm water to help cool the IP off quicker. I don't see where warm water would hurt either since it should be at a much lower temperature that your heat soaked IP. If your lift pump diaphragm is bad, you'll probably be able to smell diesel on the oil dipstick. Having the no start issue after driving but not after a long idle time is another clue to point you toward the IP. Heat is a tricky subject that would warrant it's own thread. Just remember that the coolant inside your engine will heat up faster than anything on the outside of the engine. That is especially true of your fuel system because the constant flow of fuel through your IP and injectors is there to keep them cooler. You have to heat up the entire tank of fuel before your IP will get close to being the same temperature as your coolant is. That takes a longer drive and not just idling. That isn't any type of check valve at the rear, driver's side of the engine. It's just a T that lets your excess fuel return to the tank. Lastly, your injectors and IP wear at the same rate internally. It's best if you can replace them as one set instead of just replacing one part or the other. If not, replace one part now and the other part as soon as you can afford it. That's the way to get the best performance out of your engine.

Thank you. Lots of good info! Youre definitely right about coolant temp not correlating to IP temp. That does make alot of sense. Im just going to get a new IP. I Ive been eyeing CDDs pumps but not really sure which one i should get to pair good with the banks kit. Any suggestions on best injectors and pump rebuilds out there? I dont mind paying a little bit extra if it's going to get me a little extra power and reliability.

 

[IDIBRONCO]

Go with CDD, R&D Idi Performance, or Moose Diesel. If you're not sure what to buy, call and ask for recommendations. Be honest about your wants and power goals. Be sure to let them know what Banks set up you have and if you even think that you might want to upgrade to a bigger turbo some day. Those are my suggestions.

 

[DirtyWood]

When the coolant reaches about 120*, the glow plugs aren't needed to start the engine.

Do you know where the GP controller gets the temperature input?

 

[KansasIDI]

Do you know where the GP controller gets the temperature input?

On a 6.9, it’s the back of the head on the drivers side, up top, where the original type controller is. The 87 6.9s and all the 7.3s use a computerized module that measures resistance instead, which in a way is relative to temperature.