my first CUCV m1009 has some problems need some help.

[marine0311]

I just bought an 84 m1009 barely driven it a week. I noticed that when i stepped on the gas on accident it started revving up at high RPM's i've had somene tell me it needs to warm up so we think thats solved. If it isn't pleas let me know. So know on to the other problems that came up today. I was at work and i had to move it so i started it parked it reversed on an incline then turned it off. When i came outside i noticed it leaking diesel from under the engine around the oil pan and differential. I decided to move it and parked on a flat surface while i was moving it though it started revving as if i was driving ten miles an hour i panicked and i put it in park it still revved up so i turned it off. I came back out and found it stopped dripping as bad as it used to. I started it up and it came on as usual, but i had to move it because i was in the way of someone. When i moved it the revving came back. I had no choice but to turn it off. I was on a hill now facing forward i started it back up and this time i let it sit....then it turned it off on me! i thought what is going on? either way i let it warm up for ahile but i was scared to think something was happening to it. I look to anyone who has a CUCV, diesel truck, or diesel experience to help me out. I have always been a fan of diesel and this is my first one and i really need other peoples help, experience, knowledge on what i can do to care for my first diesel truck. Thank You everyone for helping me out.

 

[nf6x]

I don't have a CUCV quite yet (my first four were supposed to show up this afternoon, but there was a mess-up with the towing company ), but I have a HMMWV which uses basically the same engine. I think.

First, I'd consider any fuel leak to be a Bad Thing that needs to be tracked down and fixed right away! Keep a good fire extinguisher or three on hand while you're working on this stuff, too.

I hope that somebody who's far more knowledgeable than I am will recognize the specific symptoms that you describe. It sounds like injection pump (IP) trouble to me. As I understand it, the IP should properly regulate the engine RPM when it's working right, and things like surging indicate IP problems. My HMMWV's engine RPMs did funny things when I first got it around 8 years ago; unfortunately, I've forgotten the exact symptoms over the years. I did end up needing an IP rebuild. Oh, wait, I'm getting a vague recollection now; I think it was very slow to respond to any throttle changes, and maybe it did some sort of surging, too.

One of the diagnostic tricks that somebody taught me was to temporarily replace the fuel return hose coming off the top of the IP with a section of clear tubing. This let me see that even after I did a complete by-the-book fuel system bleeding, I was still getting bubbles out of that fuel return port. This was the final nail in the coffin that told me that my IP needed to go to the shop. I haven't gotten hands-on with a CUCV's engine yet, so I don't know if its IP has the same fuel return line port on top. If it does, maybe this diagnostic trick will come in handy. I wouldn't recommend leaving the clear tubing in place while actually driving the truck; I just did this while running the engine in the shop.

I took my pump to the nearest Stanadyne shop to have it rebuilt. Even though it was set up differently than IPs in civilian applications, the shop was able to look up the proper calibration specs and get the necessary military-specific rebuild parts. The rebuild wasn't cheap ($650 back in 2001, if I remember correctly, plus a huge amount of my own labor removing and reinstalling the pump), but it solved my RPM problems.

 

[ssgtwright-usmc]

Clean all surrounding area of the fuel filter base, right side of engine and body frame where you see anything that may look to be wet.
Use a good engine cleaner and rinse. Do this a couple of times and let everything dry.
Start engine and inspect the fuel filter assembly area.
Most cases its the drain plugs that are bad and GM does not sell them as a seperate unit anymore.
If so, you will need to replace the whole assembly which will costs about $45 on ebay.
I have seen 2 other threads here about leaking filter bases and one thread had a wbsite listed where you can buy one directly for about $45 also and the other thread was about how one member just made his own fittings and attached them to the filter base himself.
His thread even had pictures of what he had done.
If you dont see any leaks around the fuel filter area after cleaning and running then its time to trace the lines and replace as needed.

 

[Braunchitis]

High revving is normal when the engine is cold. I believe there is a solenoid on the IP pump that controls this. It runs like that for a few minutes to help the engine warm up faster. Until it goes off, it might feel like your accelerator is stuck. You'll get used to it.

BUT I would get that fuel leak taken care of ASAP!

 

[maritimer]

from what you describe you want to have a look at the mechanical lift pump located on the passenger side of the engine block right down below the front of the exhaust manifold check the ruber lines going into it for a leak, obviously your losing diesel somewhere if its not there then check the fuel filter on the passenger side of the firewall the base may be leaking a bit. fuel leaking allows air into the system and somtimes that will cause the "rpm surge" you describe often times it will just air lock your injection system and stall your motor. without hearing/seeing it i cant be of to much help but i can tell you from expierience that theinlet fuel line on the lift pump is a sore spot in my books cause if the engine mount is weak/collapsed it will pinch the fuel line and rupture it and you end up spending 3 days changeing a perfectly good $50 lift pump leak diesel all over the place and still end up with a stalled 5500lb truck in the middle of the road lol

 

[marine0311]

Thankyou for all the responses all the information is quite helpful. I just need to know if parking it at an incline would have caused it to start leaking? It just seems like a coincidence that it started dripping fuel when i parked it on the incline.

 

[nf6x]

Parking it on an incline should not cause fuel leakage unless something in the fuel system is already broken. The fuel system should normally be airtight from the fuel pickup in the tank all the way to the injectors. There's nothing that should be open to the air like a carburetor fuel bowl.

 

[mangus580]

Real simple... you have a leak in your fuel system. The air getting in the system is causing the high revving. I have (as well as others) have noticed, there is a particular leak (have never found it) that will allow air into the system anytime its parked nose UP hill.... so who knows, you might have some sort of leak letting fuel out depending on how you are parked.

The good news is.... There is a CUCV EXPERT in Olathe (well last I knew) Brian from BRtruckparts lives there. Although I dont know how to get in touch with him anymore. I might still have an email address for him, if you need me to look, PM me.

 

[maxim]

Yup, check for leaks. I was at a swap meet and guy had this CUCCV for a long time. Drove it 1,000's miles. Got in it at the meet and it would not start. A quick check found a split and leaky line from the filter. After checking all the lines they too were rotted and with minor bending would break so the system was sucking air. New lines put on and it started right up. Put on your patience thinking cap though, as some are ...shall I say..challenging to get on and route.

 

[marine0311]

Re: RE: my first CUCV m1009 has some problems need some help

from what you describe you want to have a look at the mechanical lift pump located on the passenger side of the engine block right down below the front of the exhaust manifold check the ruber lines going into it for a leak, obviously your losing diesel somewhere if its not there then check the fuel filter on the passenger side of the firewall the base may be leaking a bit. fuel leaking allows air into the system and somtimes that will cause the "rpm surge" you describe often times it will just air lock your injection system and stall your motor. without hearing/seeing it i cant be of to much help but i can tell you from expierience that theinlet fuel line on the lift pump is a sore spot in my books cause if the engine mount is weak/collapsed it will pinch the fuel line and rupture it and you end up spending 3 days changeing a perfectly good $50 lift pump leak diesel all over the place and still end up with a stalled 5500lb truck in the middle of the road lol

we found the problem to be what you described which was the inlet rubber hose. You said the mounts pinch the line i haven't seen that yet, but i do know that it's going to be a pain to replace as i cant find the screw to unloosen the hose on top of that they put it in the most difficult spot to work in with big hands. Luckily my dad as small enough to hlep me.

 

[maritimer]

RE: Re: RE: my first CUCV m1009 has some problems need some

when you take the rubber hose off the inlet nipple look about 1/4-1/2 inch from the end of the hose you will likely see a couple little holes looks kinda like a staple was put through it, in mine thats what it looked like. everytime the engine torques or bounces from speed bumps that little nipple is pinched between the pump and the crossmember directly below it. eventully i will get around to fixing the motor mounts LOL

 

[Camolad]

RE: Re: RE: my first CUCV m1009 has some problems need some

Hi all

I have had both the filter leaking and the colapsed RH engine mount cuting the fuel line at the pump. For filter parts try a Stanadine dealer I was able to get parts a couple of years ago for mine. They had a parts breakdown for the Military unit. I was also told that John Dear was also using this type of filter on some of the tractors. I ended up removing the vaccum sensor on mine and drilled it out to accept a 1/4" plug. Leakk solved... As for the engine mount it was quite easy to replace by jacking the engine block on that side. The replacement mount had different mounting hole locations and i had to tack weld the bottom. The passenger mount seems to be the only side that needs replacement due to engine torque.(and in my case diesel leaks)

 

[Somemedic]

RE: Re: RE: my first CUCV m1009 has some problems need some

Lets not go buying injector pumps just yet kids...

We can start trackinig down some problem areas though. Areas known to be hard on rubber fuel lines. One such area is the frame rail, just behind the rear wheel well. You will notice there are 2 steel fuel lines that cross over the rail via rubber lines. Change them now. If they arent the problem now they will be shortly.

There are 2 pumps on a cucv that deal with fuel. Upon start up your starter rotates the crank which in turn operates the mechanical (or lift) pump, moving fuel to the injector pump. Mytruck had 1 steel intake and 1 steel output line on the mechanical pump, you shouldnt hav had any rubber lines. If you did, check them out. You should have all steel lines going into and out of the injector pump (looks like an octopus, front of motor). If you dont, check them out as well. Make sure the connections are tight too.

Could also change the fuel filter if you havent ever changed it yet, making sure the mating surfaces are clean. On top of the filter housing (rectangular lookinig can on the passenger side of the firewall) should be a black plastic screw with a "+" on the top. That is the drain screw and unless youve read the TM on how to bleed the fuel system it needs to be tight.

Your truck is an '84? Its probably time for an IP rebuild. To confirm, clean the IP and motor valley with some spary solvent (carb cleaner). Fire that mutha up and get a brigggghhhhtt flashlight and shine on the driverside of the IP and look for leaks. What usually happens is that some gasaket inside dies, and it leaks fuel inito the motor valley where it drips down and out through a weep hole near the bell housinig. If thats the case start saving your pennies and figuring out who your local diesel guru is. Find a certed Stanadyne repair joint in ur area to do the repair. but youo have to report back and let us cucv gurus know if we were right or just full of it. Good luck

 

[marine0311]

Re: RE: Re: RE: my first CUCV m1009 has some problems need s

let us cucv gurus know if we were right or just full of it. Good luck

Well today my dad fixed the problem i did however find the fuel leak and even before that i looked at everything else just to make sure. You guys weren't full of it at all and i really appreciate everyone's help. I've yet to become a CUCV let alone a diesel expert. I am however alarmed by the amount of factors that contibute to why the line starts to leak or go bad. I cant believe the torque or engine shaking would rin the hose. I seriously thought they would have made a fail safe fuel system. either way i bled the system, it runs fine, and i can drive it. However you said the two steel lines would end up going bad i'm afraid to deal with that let alone anything else that may catch on fire or blow up! Any reason why they would go bad if they hadn't yet?

 

[mangus580]

RE: Re: RE: Re: RE: my first CUCV m1009 has some problems ne

Keep in mind... it is over 20 some years old!

 

[ssgtwright-usmc]

RE: Re: RE: Re: RE: my first CUCV m1009 has some problems ne

So where can one go if they had to replace the steel fuel lines on a M1008/M1009?
I see some sites have them for 1/2 3/4 ton trucks but I never see anything for 1 ton trucks.

 

[mangus580]

Re: RE: Re: RE: Re: RE: my first CUCV m1009 has some problem

So where can one go if they had to replace the steel fuel lines on a M1008/M1009?
I see some sites have them for 1/2 3/4 ton trucks but I never see anything for 1 ton trucks.

The problem you will have with 'store bought' lines, is I am not sure any of them are for the diesel... and they are different.

Your best bet, is to buy a coil of line, and a bunch of fitting nuts from someplace like NAPA. Get a flare kit (mine is a cheapie from harbor freight)

And Happy bending!

I replaced all the brake lines in a Jeep Wrangler this way. It wasnt too bad, having the old lines to copy.

 

[marine0311]

RE: Re: RE: Re: RE: Re: RE: my first CUCV m1009 has some pro

So now that the porblem has been fixed can someone help me out with something else? I now know the motor mounts bad. First off. Why did the right side go bad rather than the left side since it seems to be so common? second. How do i replace the motormount without making it a long term repair(more than one day). Someone mentioned jacking up the right side to replace the mount. Is that ok?

 

[beaubeau]

RE: Re: RE: Re: RE: Re: RE: my first CUCV m1009 has some pro

I haven;t done it in a long tome. These motor mounts should be the same as regular gas job!??? Not totally sure. I have converted several Diesel to gas and all matched up. U must lift one side at a time just to release the weight on the mount. Just be patient and study your job before Attacking it!! Good luck, Phil Ps check your metal lines. Some locations are not as bod as others for Rotting lones.

 

[marine0311]

RE: Re: RE: Re: RE: Re: RE: my first CUCV m1009 has some pro

I've never really changed the motor mounts before on a car or truck. If somone could tell me how to get the engine suspended to change the mount that would be cool thanks.