No fuel

[bchauvette]

I'm trying to get my MOG running. It is obvious it hasn't run for many many years. The fuel smells like burnt gear oil. The tank is badly varnished. I've cleaned the sediment bowl, replaced the two fuel filters and blew out the line from the tank end to the input side of the filter housing. The pick up sending is very very rusted. The pick up and return lines are in a full clean 5 gal fuel can. When it cranks there is no smoke. A burst of either results in a burst of engine life. I disconnected the #1 injector tube and cranked it. no fuel. I am sure the injector pump is varnished up and stuck.

Any ideas on how to bring the injector pump back to life. Suggestion on the best place to get a rebuilt pump and possibly injectors.

 

[bchauvette]

Having studied the Tm's I decided to bite the bullet and attack the injector pump. Taking it step by step with the final solution being replacing the pump. The second major step to this goal is tilting the cab. The TM gives great step by step instructions. I already did the first step, removing the bucket assembly. Before tilting the cab I have to remove the F.O.P.S. something I wanted to do anyway. After removing the I.P. I'm going to see if I can disassemble (to a point) and clean the parts. I read and understand the TM about taking off ,installing ,timing and adjusting the I.P.

 

[marchplumber]

Good luck with the adventure! As long as you have the TM's ya can't get too lost. Is "mog" one of the freightliner models? Something like small emplacement excavator? Remember, there isn't too much that time, willingness and a TON of cash can't fix! (teasing ya!) Best of luck, and keep us informed. There are several on here that own Unimogs. Maybe they'll chip in.

God bless,
Tony

 

[tennmogger]

Hi Butch,

First, I don't have a SEE or a manual for a SEE [edit, see below]. Some things have changed from the basic 406 model (with which I am familiar). Many Unimogs sat for decades with little use. Most will start and run without tearing down the IP even if the Diesel has turned to shellac. Clean the lines and tank, new filters, and purge the lift pump, prime the system all the way to the IP and it should start. I have never had to crack an injector line to get an OM-352 to start. Add a healthy dose of Power Service (white jug) to the fuel (or additive of your choice).

You didn't mention either the lift pump, or the priming pump. You didn't mention priming the system after you changed the filters.

After you changed the filters, did you prime both filters through the bleed screws at the top of the housings? Did you locate the priming pump, and is it working (getting fuel beyond)? There are two possible types of priming pumps, one that requires unscrewing the plunger before you can manually operate it, the other, newer type, does not require unscrewing the handle/knob.

The lift pump is in the bottom of the IP. Check your manual. Do you have the operators manual, the shop manual, or the parts manual? You need all to do work on the fuel system. The basics of a Diesel engine and it's accessories (IP, filters, lift pump, priming pump, etc) are basic, but MB and Unimog do it "their way". You need to know how they did it.

Your description sure sounds like fuel problem, as you said.

Personally, the last things I would do are disassemble the IP or lift the cab. Both are real PIAs. There's really good access to the IP and fuel system behind the top of the right front wheel. Take the wheel off if you need to.

The ROPS and FOPS system is one of the assets of this truck. I'd have to have a really good reason to defeat that system. If you are stripping down the SEE to make a lighter truck out of it, daily driver, trail buggy, whatever, the ROPS, at least, might save your butt. A Unimog is generally very stable with a low center of gravity, but the 406 series, SEE included, are short and tall. They will flit over.

You might want to sign up for the Moglist and Unimog forums on BenzWorld.

[here is a manual: http://www.rockymountainmoggers.com/pdf/TM5-2420-224-10.pdf
Ron DePugh's RockyMountainMoggers website is loaded with good information, mog adventures, etc]

Good luck.

Bob

 

[bchauvette]

I too off the lift pump dissembled, cleaned and reinstalled. Didn't see anything remarkable. There is defiantly fuel running through the IJ via the lift pump. Removed #1 feed tubed and cranked, nothing. The chances of what ever is wrong is times 6 is possible but not likely. The question is When you have fuel running thought the IP but no fuel coming out what common thing would cause this? I did check the throttle/shut off visually and is seems to be working. Can I access the fuel shut off components with out taking the IP off? Question 2 If the problem is individual circuits times six what in an individual circuit would cause no fuel flow?

Today.I am going to remove the feed tubes, remove the components on top of the IP and clean them, Fill the cavities with injector cleaner let it soak then reassemble, make a livsacrificefice to the MV gods. I think a fatted calf is in order. I am going to make sure the parts kepteped together to their individual station. I will not use a magnet to lift parts outsout of the IP per the TM. I'm also going to dig into the fuel shut off stuff. I imagine when you pussh the throttle/shut off lever all the way in all it does is move the IP reck gear all the way turning the plungers to stop fuel flow to the injectors. I think I just answered my own question. This is the one thing that pevents fuel flow in all 6 circuits.

 

[marchplumber]

Keep at it! "Slow but steady wins the race"

God bless,
Tony

 

[tennmogger]

Hi Butch,

You seem to have a really good handle on chasing the problem. The final goal is to get the air out, of course. I think you said you can circulate fuel all the way back to your jerry can by pumping the primer pump. You may be on the right track by looking at the fuel shutoff components, too.

Just in case the lift pump is not pumping or air locked, you might elevate the jerry can fuel source above the IP during your testing. I have had good luck using some sort of spray lubricant as a 'starting fluid' to sustain engine running during brief hard-to-start testing. That provides lubrication for a dry system and helps initial compression.

BTW, I was about 15 miles from Easley last week (exit 27 on I-85 at the big RV dealer there).

Bob

 

[bchauvette]

Made good progress yesterday in-spiteof having to give several army truck tours. Gota keep the neighborhappy. Was able to separate the governor assembly from the pump bodywith the pump still attached to the engine. It appears that the rackgear is locked up in the fuel off position. The next step is toremove the pump and slowly and carefully free it up.


Getting there is part of theAdventure or you can't get there from here.


Here are thesteps to get to opening the pump. First I didn't have to tilt the cabbut I did have to take some liberties. First I removed the front lefttire. Thanks for the tip it was the key to success. Then I had toremove the compressor intake tube. The tube is screwed into thecompressor head then snakes along side the engine in front of the oilfilter assembly that needs to be removed. They expect you to take thecompressor cylinder head of to get the tube off. I cut it instead.Will put a hose and hose clamp union when I reassemble. Next Iremoved the the oil filter bracket assembly. One of the bracket toengine block fasteners is a hex head cap screw. Under normalcircumstances it would have just cleared the top of the frame. Butthere is a 3/16 strip welded to the top of the rail the whole length.Possibly for additional strength. So the cap screw didn't clear by byless than a 1/16. I jacked the engine up against the mounts the 1/8”to clear. I'm going to cut the cap screw by 2 threads forreeassembly. I disconnected the IJ actuating shaft from the back ofblock crank arm. Six screws on the injection pump a sharp tap with asoft hammer and the back of the pump was off. You can only separateit a couple of inches because of the governor arm to rack gearconnection. Just enough to see what is going on.


Horrific engine oil


Ihave a bad feeling that the engine oil and filter are original. Theoil is horrific. I was getting over 80 PSI oil pressure by justcranking. I doubt they re-paint the drain, bleed and fill plugs onthe oil filter housing assembly. It had a Mann oil filter withEnglish and German writing on it. There is less that 85 hours on themeter. I hope there is not too much damage. I'm anal about changingoil.


There is a approx 2 gal tank hangingdown from the oil pan where the drain plug should be to increase theengine oil capacity. It looks like a tumor. I hope I can remove itand go back to original oil capacity when I drop the pan to clean thepan . I've seen a lot of Oil pan modifications this is the most MickyMouse ever.


Today I'm going take out the InjectionPump. The M944A1 is across the driveway from the MOG. While I'mworking on the MOG I hear whispers in the breeze from across thedrive way..... “Drive me.....Drive me...” I hear that if youdon't heed the voices you will go insane or in my case more insane.


Picture in my Da MOG album

 

[expeditionimports]

I believe you are talking about the ORIGINAL Factory oil pan. Tumor yes, Factory yes, Needed absolutely. Remember the Unimog is designed to run well at extreme angles, the deep sump helps to allow that to happen. You are quite likely to destroy the truck if you try to remove the tumor. A quick photo posted and people should be able to tell you whether you have a stock pan, or someones modification.

We have resurrected 6-8 SEE's that were in horrific shape. We've never had to pull an IJ pump to get it to start. We've definitely had to rebuild them to get proper performance, but 99% of the time the issue with startup is an air lock. Stanadyne is your friend on these to get rid of the varnish. Good luck with the project, if the pump does turn out to be completely bad you may find it cheaper to find a replacement then to rebuild. Last OM352 pump that we sent out for Bosch rebuild was about $2200 with injectors. A good used pump is fetching in the $400-500 range.

 

[bchauvette]

View attachment 414933View attachment 414934

Here is the picture of the crank case tumor. The other picture is pointing to the IJ rack gear. I assume you should ba able to gently push it back and forth. Crorrect me if I am wrong. Please correct me on this, You should get fuel out of the port on top where the pump to injector tube goes when you turn it over. On one hand I'm nervious I am going in the wrong direction with this with you telling me you never had to remove an Injection pump.

 

[expeditionimports]

That is the standard Oil Pan, nothing non-stock there and I would not even think about modifying it.

I can't tell you if you are going down the wrong path, but I can tell you what we do on a normal dead truck start up.

1. - Check Engine Oil
2. - Check Coolant
3. - Replace all Fuel, and Fuel Filters, and clean the pre-filter
4. - Replace lift pump hand primer
5. - Open front fuel filter bleed screw. - Pump hand primer until clear fuel is coming out the bleed, with no air. Close front fuel filter bleed screw.
6. - Open Rear Fuel Filter Bleed Screw - Pump hand primer until clear fuel is coming out the bleed, with no air. Close Rear fuel filter bleed screw.
Model Variation, you may or may not have an additional bleed on the pump.
7. Follow output filter line to IP, if there is a bleed screw at the incoming line banjo, crack and pump until clear.
8. - Depress the accelerator fully and crank the engine. Keep the accelerator fully depressed until all cylinders catch, then release. Engine will buck and sputter and act like it has no power until all the air clears out and then it will come alive.
9. I am not a fan of ether unless you are very well versed in regards to how much to introduce into the intake. I've seen catastrophic damage from incorrect usage. As a rule of thumb we don't use it in our CA temps. Below zero and it may be needed.

Sometimes it may take 2-3 try's with bleeding the system before we get it to take off......but they always take off.

As an aside, if you are running ULSD in your tractor you MUST run a lubricity agent to ensure long lasting life. I can forward the Bosch service bulletin on this, but it is clear that the ULSD has a MAJOR negative impact on the Bosch mechanical pumps. We use the stanadyne products and have been pleased. (I buy it by the 5 gallon....)

 

[bchauvette]

I very much appreciate the time yourspending to help me, Thank you.


Our start up lists are exactly thesame. But I didn't replace manual prime pump. I took it apart andcleaned it. I didn't notice any bleed screw on the fuel input area ofthe IP. I did crack the fuel line at the pump and bleed it.Additionally I disconnected the feed fuel line at the pump and blewinto the tank pick up end . First it was clogged. At the tank wherethe feed fuel line transitions from plastic line to thepickup/sending unit there is a rubber hose clamp union. There is ametal fitting pressed into the plastic line so the hose clamp doesn'tcrush the plastic line. It was completely plugged with rust. Icleaned it and was able to pass gas after that.


I am only 5 bolts and 6 injector tubesaway from removing the Injection Pump so I will proceed. I lovedupping out how things work.


I assumed the crank case tumor was anarmy thing and not a MOG thing. I will definatly leave it.


In your opinion should I be able toeasily move the rack gear back and forth. I imagine a governor aswhat I call “Spring Nirvana” (An ideal condition of rest, harmony, stability, or joy).The throttle mechanism ends up at aspring opposing an other spring pulled by the governor weights. Thebalance point is where the rack gear is set for that particularsetting. The spring above the pointing pencil in the picture is thethrottle lever spring part of the equation. To me the size of thespring gives me an idea on how much force it should take to move therack gear.


You have no idea how important yourLSDF additive comments are. No doubt you save the lives of my M944A1(M.O.M. Mother of mom), Da Mogster and Yanny Yanmar (John Deeretractor). Which specific additive do you use?

 

[bchauvette]

I apologize for the jumbled and run together text. I noticed on an earlier post that after I spell check It scrambles everything. I have to go back and fix it. I composed my last reply on my word processor then spelled checked. Re-read the post then cut and past to the site. Now I see I still have words running together.

 

[bchauvette]

Well I got the injection pump out. The rack gear wont go back and forth and I can't figure out why. The rack isn't totally jammed you can twist it back an forth ever so slightly . I can wiggle The little pinion gears that engage the rack(Feel the back lash) . All six piston springs are in a compressed state. The tappets actuated by the cam just kisses the piston with no appreciable movement to the piston. I've taken the pump apart as far as I dare to go. I'm looking for recommendation on where I can send the pump to be repaired or buy a good used. The MOG has ony 84 hours on the meter.

 

[bchauvette]

I went as far as I could go. I dropped the IP off at a diesel shop. The guy says he has experience with Bosch pump locked up rack gears. He said it is actually froze up pistons. Me thinks it is a case of bad oil and sitting for so long.

B.T.W. I have never seen so many mud dobber nests in my life.

 

[marchplumber]

Well, keep us informed! Always like learning w/and from others!
God bless,
Tony

 

[bchauvette]

Well we have the worst case scenariosfar as a locked up IP goes. It's gonna cost $1,100.00 to fix. Thetech. Told me that if the pump is that bad the injectors are morethan likely shot. I got one injector out but I really need to have apuller to get the others out. I'm going to see if I can get the Powergenerator and lathe going on M.O.M. (M944A1) and fabricate a puller,I was a machinist in an earlier life, and/or bring the one injector Ihave out to Lowe's and gin something up. If the generator and latheworks I will be very surprised.


One thing this adventure proved is that you can do all this work with out tilting the cab. Easier saidthan done. I did have to cut the compressor metal intake tube so notto have to take the air compressor head off. The tube can easily beput together with a rubber hose and clamp union. The cap screw forthe oil filter bracket hits the frame rail welded reinforcement platewhen unscrewing. The engine has to be jacked up 1/8 inch to clear.Will shorten the bolt by 2 treads. The right side windshield wiperstud need to be removed along with the wiper connecting rods. Theassembly needs to be pushed upwards so the valve cover can to comeoff. The injector fuel supply lines do not have to be completelyremoved. The Fuel filter bracket need to come off. The engine liftingbracket neat the fuel filter bracket need to com off. You need tofind the throttle arm tension spring that goes flying when you takeit off. .
The fuel that drained out of the supplylines when I unhooked them looked and smelled like dog urine.


There are a bunch of MOGs currently onGL. Most are not running. This seized IP thing might be systemic forMOGs that have been sitting for a long time. WE might want toconsider this when we are bidding for these.


The hour meter show less than 80 hours.There is thick paint on all the fasteners showing no work done onthem. But the MOG shows all the signs of being run hard and put awaywet. I have a lot of mechanical experience. This machine has receivedvery poor maintenance and has signs of abuse. Yet the M944 istotally “Combat Ready”, pristine condition. Why do suppose thedifference? Is there a post on what the life sequence is of a MV?What stages do they go through up to end of Military life?


I have this nightmare I keep replayingin my head. When I get it running I find out it has a knock. I musthave gotten this MOG confused with an other. I though it was runningrecently and quit. I paid the higher end for it thinking it had runrecently. When I went t Pineville to check it out there was air inthe air tanks. Imagine holding compressed air for all that time!

 

[bchauvette]

Pressure washing the fuel tank worked beautifully. Put two street elbows at the end of the pressure washing wand to reach the nooks and crannies and the inside top of the tank. Much to my surprise M.O.M.'s generator, lathe and compressor work perfectly. It took a couple of minutes to figer out you throw the PTO lever back not forward and how the engine speed control works. If anybody needs an injector puller let me know. I made an extra. Not pretty but woks well. 1 ea 3/4-10 X 1-1/2 bolt, 3/4-10 nut, 3 ea 3/4 washers, 3 ea 3/4 galvanized pipe coupler, The bolt head is turned dound to just under the injector OD, The head side of the bolt is drilled and tapped to 9/16-18 Just deep enough to encompass all the injector threads. The pipe couplers are drilled out to just a little bigger than the injector OD. After removing the the feed lines Injector clamping rings with a 30MM deep socket(Northern Tool) the 3/4 stud is screwed onto the injector, The three drilled out couplers are piled up around the bolt and injector, washers over the bolt, nut turn and Ta-DA injector in hand. You may want to blow out the injector well before pulling the injector to clear out the oil from poring into the cylinder.

 

[marchplumber]

Best of luck with your machine! Hard to believe so few hours and so much headache.
God bless,
Tony

 

[bchauvette]

Actually not a headache at all, but the adventure. I'm sure we all realize that this government surplus is a crap shoot (not dice). I love working out these kind of challenges. It is a big reason I went down the MV path. I love being in the Lowe's plumbing department looking for parts to make a Mercedes truck engine injector puller. The biggest problem is that I am on a fixed income. The money spent will cause a delay in insuring and registering the MOGster. It will also seriously reduce my M.O.M. (M944A1) therapeutic drives. I got a brain fart for some reason I thought the MOGster was recently running. I paid what I calculated was a running price. I would be very reluctant to buy a non running vehicle unless the price was low enough to cover serious engine work. B.T.W. All of a sudden I can't do new paragraph returns and I'm getting "while typing" spell Checking.