'86 M1008 cranks too slow to bleed

[leedraper]

Before I start, I'd like to say a huge thanks for this website and the people that post on it. It gives me hope for the country and the world in general that so many caring and knowledgeable people exist and are willing to take the time to share. And a big up to the admin staff for its creation and the thoughtful policing and policy enforcement.

The facts as I remember them:

1986 CUCV M1008 Diesel, 1 1/4 Ton, 45k miles
Had truck about 1 year and it had zero probs, highway, farm, loaded and empty.
<smacking forehead> Ran fuel too low and when it started stuttering, shut it down. <smacking forehead>
Drifted downhill about 100 yards, parked. Continued smacking forehead at this time.
Next day, poured diesel in tank. Read bleed instructions found here. Excited to fix it so easily. Turned key. Slow crank (like dying battery). Wrinkled brow. Had 30 days prior put commercial battery in and until just now was spinning like a top when starting. Walked 200 yds to house, looked at refrigerator (beer inside), paused, but continued to shop for multimeter. Both batts read 13.5v +/_.
Took all electrical connections apart, cleaned, scraped and threatened severe bodily harm for poor performance. Re-assembled all. Turned key. Still slow crank. Thought of beer, but 200 yds.........

Disconnected batteries, Hooked charger up for 12 hrs each. (Beer involved at this point) Read many posts here. Stared at TM until dry-eyed. Looked for second starter relay under dash (some disassemble required). Thought it was not there, but found it with pictorial assistance. Later.

Checked batts. 14.v in back, 14.1 up front. <smiling> Turned key. Starter barely turned over. <NOT smiling>

Walked past fridge to laptop. And so here I am.

Thanks in advance.

Lee

 

[85CUCVtom]

Disconnected batteries, Hooked charger up for 12 hrs each. (Beer involved at this point) Read many posts here. Stared at TM until dry-eyed. Looked for second starter relay under dash (some disassemble required). Not there!

The starter relay under the dash is missing? I'm not sure if the truck would even crank if that was missing.

 

[txmytx_catahoula]

Do you have access to a battery load tester? Looks like a ramped up volt meter, but tests the voltage under a load. There are times a battery will show 12-13V but then drop to nothing under load. Something I did while bleeding the system was to remove all the glow plugs. No compression equals a REALLY fast spin over. Check the batts then connections.

Good luck and let us know how it goes!!

 

[leedraper]

Oops. I did think it was missing until you made this comment. I got a pic of it from the doghead mad and, ahem, there it was. Thanks.

 

[wallew]

Do an advanced search on 'electric fuel pump' here in the CUCV forum.

If you ADD an electric fuel pump, when you turn on the key, you will get 5/6 psi AT the fuel filter and won't NEED to crank your truck to bleed it.

been there, done that. easiest fix I've found for bleeding your fuel system.

 

[K9Vic]

Yes, electric fuel pump is the way to go, let me explain why.

I found out today that the fuel gauge on my M1031 is not as accurate as I am used to with these trucks. I backed into my driveway that is on an angle of about 5 degrees and it died on me, fuel was on the first line next to empty. So I filled my portable diesel tanks and put more fuel in the tank.

Now these trucks are a PITA to prime with a mechanical fuel pump, but luckily I installed an electric one. So it was really easy to prime the system with the fuel pump running not cranking over the engine. Let all the air run out and after about 10 seconds of cranking it started right up (EDIT: it was only about 10 seconds, checked my security video footage).

So this is the advantage of the electric pump, easy to prime the system.

---

Clean and sand all your electrical contact on the entire truck, especially these. I had a M1010 that I worked on for a friend that cranked over real slow and did not start well. I cleaned all the contacts on the main power block and after that it cranked over fast. This is a 12v converted CUCV, but it should still turn over faster than it did.

24v Pos & Neg power block on firewall.
Alternators connections.
Small power block near glow plug relay

 

[MarcusOReallyus]

Well, first of all, welcome!

<smacking forehead> Ran fuel too low and when it started stuttering, shut it down. <smacking forehead>

Let me help you out here: We have a smiley for that. It looks like this:

When you need it, just click the "More" link. When you're composing a post, it will be over there on the right just under the other smilies. Gotta use the right tools for the job, y'know.

Took all electrical connections apart, cleaned, scraped and threatened severe bodily harm for poor performance.

Yep, you're one of us.


But back to your problem.... Cables okay? Or the starter might be going, mebbe? Coincidence does happen once in a while....

 

[rickf]

I am glad to see you read up before diving in. You covered all of the bases before asking questions, good job! An electric pump is the easiest way to prime the system but I think right now he wants to get it that 200 yards back to the house. I would second the glow plug removal, as long as they are not swollen they will come out easily and make it spin better. It sounds like your starter is going out. Did you also check the ground wire between the engine and the bus bar on the firewall? NOTE!!!! When you turn on the key the wires for the glow plugs will be live, put a bit of tape on each one.

Rick

 

[Keith_J]

Purging the fuel system is easy with a MityVac hand vacuum pump. Connect the reservoir to the pump, then connect to the top purge fitting. Unscrew the valve on the filter body fully, then plug the fitting boss with a suitable plug or even your finger. Draw a vacuum with the pump until you get fuel in the reservoir.

This will prime the mechanical pump and filter. The rest will purge with 30 seconds of cranking on the starter.

 

[unaffiliated]

Before I start, I'd like to say a huge thanks for this website and the people that post on it. It gives me hope for the country and the world in general that so many caring and knowledgeable people exist and are willing to take the time to share. And a big up to the admin staff for its creation and the thoughtful policing and policy enforcement.

The facts as I remember them:

1986 CUCV M1008 Diesel, 1 1/4 Ton, 45k miles
Had truck about 1 year and it had zero probs, highway, farm, loaded and empty.
<smacking forehead> Ran fuel too low and when it started stuttering, shut it down. <smacking forehead>
Drifted downhill about 100 yards, parked. Continued smacking forehead at this time.
Next day, poured diesel in tank. Read bleed instructions found here. Excited to fix it so easily. Turned key. Slow crank (like dying battery). Wrinkled brow. Had 30 days prior put commercial battery in and until just now was spinning like a top when starting. Walked 200 yds to house, looked at refrigerator (beer inside), paused, but continued to shop for multimeter. Both batts read 13.5v +/_.
Took all electrical connections apart, cleaned, scraped and threatened severe bodily harm for poor performance. Re-assembled all. Turned key. Still slow crank. Thought of beer, but 200 yds.........

Disconnected batteries, Hooked charger up for 12 hrs each. (Beer involved at this point) Read many posts here. Stared at TM until dry-eyed. Looked for second starter relay under dash (some disassemble required). Thought it was not there, but found it with pictorial assistance. Later.

Checked batts. 14.v in back, 14.1 up front. <smiling> Turned key. Starter barely turned over. <NOT smiling>

Walked past fridge to laptop. And so here I am.

Thanks in advance.

Lee

The exact same thing is happening to my M1008 after running it out of fuel. Mine is also about 200 yards from the house give or take. It seems like a mile after I walked back up to the tool box 50 times.

Anyway it spins over like gangbusters with the glow plugs removed but when I put them back in, a couple of revolutions and just like the batteries were dead. I even put the known good batteries from our 02 Dodge Ram Cummins Diesel and the same thing, a few revolutions and just like dead batteries. I am getting 26 or more volts together and 13.8 separately at the batteries. I did crack all the injectors loose while the glow plugs were out and I think I got the fuel system bled out, not 100% sure.

I cleaned terminals for what seemed like hours but that did not help. I finally gave up and went to look in the fridge, darn, no BEER. Crap-o-matic. I did not clean the ground cable from engine to terminal block or all the cables on the terminal block itself. I guess I will try that next.

I think my starter may have crapped out. I have access to a known good starter, I just have to talk my friend into bringing it with him from Mississippi. I really would like to get it to the house so I can fix the broken bolts that hold the trans to the engine and drive the darned thing. Let me know what you find, maybe the same thing is wrong with mine.

 

[Skinny]

I'm not sure how some people are having such a hard time bleeding the system. I have replaced the filter and IP which air locked the entire system and had no issues bleeding without killing the batteries.

A spin on filter helps because you can fill the filter up unlike a box filter. It took me no more than two sets of 15 second cranks to bleed the filter assembly and three sets of 15 second cranks to bleed the injector lines. I did allow for a lot of cool down time between.

I think you will have issues if you have weak batteries, a worn out starter, or you crank for too long overheating the components. I understand the added convenience of an electric fuel pump but making an overly simple diesel engine rely on an electric fuel pump makes no sense to me. It worked fine from the factory so why ruin a good thing...just my two cents.

 

[leedraper]

Thanks everyone for the on-point comments. I'll resume the story.......

the CUCV project has been on hold for a variety of work and farm priorities, but with the impending Frankenstorm, I wanted to get it done, so.....

• I cleaned every electrical connection that was suggested 'til they shone in the dull morning light (I even clipped our labs' toenails cuz I was on a roll)
• Had wife turn key while I watched multimeter drop to 9.2 volts
• I then replaced both batteries with known good ones (loaners) (new Bobcat battery and wife's diesel VW)
• Wife again turns key....it spins like a Russian ballerina! Opened bleed (jug under tube), disconnected pink wire on injector (oops, forgot this before), cranked it again until clear (2 ten second cranks).
• Take wife's place behind wheel, turn key.........................it runs! Give a little throttle until it idles, exit truck and whoop like we just won the Superbowl!
• Gather tools, joke with wife, hat blows off from big gust of wind. Why do I mention this detail, you might ask?

Same gust of wind (or perhaps one that immediately follows) yanks hood back and springs it. Yup, PERFECT timing! If I wasn't so happy that I could actually drive back to the house, I might have flipped out. The hood does close and latch but it only goes up about 36" and needs a brace to hold it up.

Thank the gods that I can laugh at all this. And I haven't yet mentioned the brake issues.

Again, thanks to everyone who was so thoughtful and informative. Now back to Storm Central.

And to unaffiliated: I'm clearly not qualified to advise you on CUCV mechanics, but IMHO your problem is obvious: You need BEER in the fridge prior to any complex, delicate or crucial mechanical endeavor! Best of luck with your own starting issues. I'll drink a beer for you!

 

[Skinny]

So maybe the admin's can make a sticky to three crucial items when trying to bleed the fuel system:

1) TM procedures
2) Two batteries in good condition
3) Beer

Glad you got it fixed!

 

[unaffiliated]

After talking to my friend in Mississippi, we have both come to the conclusion that the starter is the culprit. He is gonna bring a known good one with him when he returns to Atlanta later on in the week. It just can't be batteries because it does the same thing with the known good batts from the Dodge.

@leedraper. I agree with you on the beer issue. I work on Mercedes for a living, have for 34 years, and American cars are 'Foreign' to me. I have always said at the shop "If I am gonna work on an American vehicle, I'm gonna drink beer while doing it".

@Skinny. The last time I changed the fuel filter, I had no problem what so ever bleeding the system. I put a hose on the bleeder port and stuck it in the fuel jug, when fuel came out, I closed the bleeder and boom she was running. This time after running completely out of fuel, it just doesn't want to cooperate. But I am not a quitter and she will not kick my arse.

 

[leedraper]

Cheers!