M1009 Rebuilt IP problems

[Mwg89]

Recently I sent my ‘86 M1009’s IP to Diesel Care in Memphis for a rebuild. Got the rebuilt pump back on and got it bled, finally... now I go to start the truck and of course it doesnt sound happy but if I let it sputter along long enough or if I give it a little fuel the RPM just takes off and does not return to idle.. RPM will continue to climb until I shut it off. Throttle cable and throttle shaft are functioning properly. Am I missing something? Any help is appreciated.

 

[cucvrus]

Hard to tell from afar. Try and disconnect the throttle cable and start it. Does the throttle shaft return freely and open freely. Was it dropped and has a slight bend to it? How does it act with the throttle cable disconnected? Report back. Is this the first pump you ever changed? Diesel Care will make good if you have issues.

 

[Mwg89]

Thanks I will try tomorrow, but I can tell you that the throttle shaft feels smooth throughout range of motion and the cable is new, so the linkage from shaft to pedal is all smooth and nothing hangs up. The pedal moves the shaft full motion open to close and returns as it should. Idle is pretty rough and very low RPM, and if I touch the accelerator at all its off to the races. Timing mark is barely just a hair to the right of the mark on the engine, but I cant imagine it has anything to do with timing. This is the first pump I’ve ever changed.

 

[cucvrus]

New cable. Where did you get a new cable? Is it a Genuine GM Cable. I heard of these problems with new aftermarket cables. Lay them side by side and compare. I think that may be where the problem is. Good Luck.

 

[Mwg89]

I got it online a while ago, not sure what it is but Ive put a lot of miles on the truck with it without issues. Old cable was toast and is long gone.

 

[gringeltaube]

Have you informed the rebuilder of your issues? What did they recommend?

 

[Mwg89]

I talked to Diesel Care and they sent a label to ship the pump back. However when I went to start the truck earlier today it started up and acted normal. Smoothed out and everything feels like it should. Maybe it was air working out? But this brings me to my next problem, which was the original reason I had the pump rebuilt in the first place. After running it for a while I took it down the road and all is good..parked it for a half hour and tried to restart to no avail. Before I sent the pump away I was having trouble starting warm. Let it sit overnight and it would start right up. Installed a manual glow switch which did help for a while but eventually manually glowing did not start it either. Now it seems to be exhibiting the same symptoms. Loss of fuel prime doesnt make sense to me as it starts fine after sitting overnight. I also didnt touch anything in the fuel system after it sat last night, and it started right up this morning. Lift pump is an electric diesel from napa, and I had good results with it before the warm starting issue began. When i bled the system the other day it was pumping fine. Fuel filter is a napa spin on that I installed 2 years ago because I was loosing prime with the box filter setup. IP shutoff solenoid clicks as it should. Im not really sure what to do next.

 

[Mwg89]

After the truck sat overnight it once again started no trouble..instant start. Let it idle for 5 minutes or so, shut it off and waited a few seconds..now it turns over a few times then catches. Shut it off, wait...now its getting harder to start. Third time it never caught. Glowplugs activated each time. Perhaps the problem isnt temperature related.

 

[tom lovinggood]

I am having a similar problem, but, not cable related. Had a rebuilt IP installed over the summer, and my M1009 seemed to run ok other than than a slightly fast idle. This morning, the idle just got faster and faster, then, the engine shut off completely, and would not re-start. Am having it towed Monday morning.
Tom Lovinggood

 

[cucvrus]

I talked to Diesel Care and they sent a label to ship the pump back. However when I went to start the truck earlier today it started up and acted normal. Smoothed out and everything feels like it should. Maybe it was air working out? But this brings me to my next problem, which was the original reason I had the pump rebuilt in the first place. After running it for a while I took it down the road and all is good..parked it for a half hour and tried to restart to no avail. Before I sent the pump away I was having trouble starting warm. Let it sit overnight and it would start right up. Installed a manual glow switch which did help for a while but eventually manually glowing did not start it either. Now it seems to be exhibiting the same symptoms. Loss of fuel prime doesnt make sense to me as it starts fine after sitting overnight. I also didnt touch anything in the fuel system after it sat last night, and it started right up this morning. Lift pump is an electric diesel from napa, and I had good results with it before the warm starting issue began. When i bled the system the other day it was pumping fine. Fuel filter is a napa spin on that I installed 2 years ago because I was loosing prime with the box filter setup. IP shutoff solenoid clicks as it should. Im not really sure what to do next.

I would start by seeing if it is getting fuel to the out side line of the filter. If it were a truck brought to me I would start by removing everything that was not original. And from there I would trace the fuel lines. I would check them for leaks. No really I don't know where I would start on someone else's vehicle. But I used to find CUCV's for sale that were not running right. I would push, pull, or drag them home. I would start working at the back and work my way front. When I was completed I never bothered finding why they were malfunctioning and not running. When I was completed they ran as they were supposed to. Many little things can lead to big things. I am sure you know that. Good Luck. I hope you find the issue. But I don't know your setup and from a far I can't be much help. Check for fuel delivery first and glow plugs second. Happy New Year.

 

[Mwg89]

Put a clear tube on the return line coming out of the IP. At first I saw some sand grain sized bubbles so I went around and checked/tightened a number of hose clamps in the fuel line. Bubbles stopped. However, still whenever I shut it off its immediately done. Today it was running for maybe 5 minutes, turned it off and immediately tried to start again.. will not start. Im starting to wonder about the injectors. Just doesnt make any sense to me at all.

 

[cucvrus]

Do you have a connection going to your injection pump that looks like this? And is it getting fuel all the time?

4 Common Fuel Injection Pump Problems - Troubleshooting Diesel Engine Problems

Fuel injection pump performance is closely tied to engine performance, so if you're noticing issue it could be due to 4 likely problems. View them here.

www.buyautoparts.com

 

[Mwg89]

Do you have a connection going to your injection pump that looks like this? And is it getting fuel all the time?

4 Common Fuel Injection Pump Problems - Troubleshooting Diesel Engine Problems

Fuel injection pump performance is closely tied to engine performance, so if you're noticing issue it could be due to 4 likely problems. View them here.

www.buyautoparts.com

View attachment 786529

If youre talking about the electrical connection, yes all of the connectors are there and everything functions as best I can tell, except the high idle solenoid, that does not work. IP is getting fuel and the return line is always showing fuel. It will start right up cold and run fine, go down the road and back as many times as you want, no sign of fuel delivery problems..but turn it off and its done. I tried the water over the IP trick and that didnt have any effect.

 

[Mwg89]

Old thread, same problem. I have replaced injectors with no improvement of my warm start problem. To recap, M1009 quit starting when warm, installed manual GP switch and that worked for a few days...then no warm start even with glow. Sent IP to DCP Memphis for rebuild, installed and have same problem. Took the top cover off and removed fuel shutoff solenoid and cleaned, although it wasnt very dirty to begin with. Solenoid does click when connected to pink wire so I believe it is functioning fine. Truck starts instantly when cold. After running for say 10 minutes and shut off for more than 10 seconds or so it will not start. Water over IP has not worked for me. Cracked a few injector lines when warm and do not see nearly the fuel I see when cold. Have good fuel delivery up to the IP. This leads me to believe that although the IP was rebuilt, it is still faulty. I assumed a rebuild would address head and rotor wear.... Anyone?

 

[cucvrus]

Real hard to help from afar. I spent the day fixing a CUCV owner thought it would be a good idea to sand blast the inside floor of the cab. Guess what happened. Had to say I told him so. But from your description it is hard to just say yes its the injection pump. To many variables. The nozzles are getting fuel it should start. But what about glow plugs? Air leaks. I would help if I could but would only be guessing. I used the rebuilder you mentioned many times with rave results. Does it always have electric to hold the injection pump valve open? Just shooting from the holster here.
Be Safe. Good Luck.

 

[Mwg89]

Glow plugs are less than a year old and truck has no problem starting cold so I would assume they are fine. There could be an exception to this but if its sucking air somewhere I would expect it to lose prime, and that is not the case. It can sit for a month and start right up, and it will run as long as you want with no problems. It would seem strange that an air in fuel problem would manifest only after shutting down and then eventually sort itself out. As for the nozzles I would say that there is hardly any fuel coming through the lines when cranking warm after shut down. A slight drip if anything. What I have read about the DB2 is that a worn head and rotor can make pop pressure when cold, and continue to make pop pressure while running as the fresh fuel is thick enough to maintain pressure. When the engine is stopped the fuel sits there and becomes too thin for the worn head and rotor to make pop pressure. 12v to solenoid is always operating fine, I always hear the solenoid click when I check it and the connection is solid.

 

[rmesgt]

Is it possible that the problem is in a fuel line? I don't know enough about the CUCV fuel delivery system, so I don't know how much rubber is involved. I can tell you that I had brake trouble a while back. The brakes would apply, but they wouldn't release. The problem turned out to be the interior of the flexible rubber hose. The rubber was old and deteriorating. It would allow the fluid to pass through the line when the brake was applied, but when released the fluid was not allowed to return. I realize that brakes and fuel are not related, but perhaps there is some sort of rubber fuel like that is collapsing or failing when warm.

I wish you the best. Please let us know what you discover...