Leaking Fuel - Injection Pump & Other Leaks

NussBus

NussBus

Member
Recently the van has been starting hard really hard or not at all. I noticed a leak from the top of my fuel filter housing. It seems to be leaking from under the priming plunger so I suppose that needs to be replaced. Is there an O-ring that I can just replace?

I was finally able to get underneath it today and noticed diesel leaking from what appears to be the bottom sides (both) of the injection pump. The image below is NOT mine but I found it on the UK forum and it clearly points out where my leak is coming from. Does anyone here have any experience replacing the O-Rings behind those plates? Is it a tough job? Can it be done with the pump still installed or does it need to be removed from the engine first?

Thanks for your input!
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crespi said:
Any success/progress?
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Kind of...
I found a fuel filter housing online from a Chinese Supplier called Kowze Auto Parts on the website AliExpress. (link is here) It was $30 with free shipping. Although the shipping will take a while, it's still much cheaper than a supplier I found in Canada who is asking $158CAD.

I also found the model number of the injection pump - there's a badge on the side of the pump that says MD171460 (the Mitsubishi number) and underneath that it says 104740-8230. I checked with a local diesel fuel injection service and they said that the pump was made by a company called Zexel and that 104740-8230 is the Zexel part number. The had both the reseal overhaul kit and the IP front seal in stock for $26. If anyone is in the Portland metro area looking for these parts, the shop was called Diesel Fuel Injection Service. They were super helpful and can overhaul the kit there if you don't want to mess with it yourself. I've found some good resources online for the overhaul process. The first is this website, which has a super detailed breakdown of the dis/reassembly of a Bosch VE pump, which is very similar to mine. And here's a schematic of the pump and it's parts. It looks pretty daunting, but I figured it's worth a shot vs the cost of a rebuild at the shop for $550-$850. As long as I'm meticulous about keeping things clean and organized I think it'll be OK.

So, I've got parts figured out, but now I just need to figure out how to remove the IP. I can't seem to find any clear walk throughs on any forums for how to do that job. And I don't know how it'll need to be adjusted after I take it apart, overhaul, and reinstall. Any suggestions or resources would be MUCH appreciated.
 
How much was DFIS going to charge for the overhaul if you don't mind me asking? I need to get mine fixed (their leakyness is pretty common from what I've heard) and was quoted $1,000 from a shop in Portland to pull it out and send it to DFIS and then re-install it.
 
Looks like you've done a good amount of legwork on the part/schematic front. I'm only having issues (I think) with the filter housing. Having trouble keeping the system primed, so I appreciate the cheap housing link...the OEM Coombs one was a little steep.

I'm interested to see how your rebuild goes, though. Good luck!
 
natematos said:
How much was DFIS going to charge for the overhaul if you don't mind me asking? I need to get mine fixed (their leakyness is pretty common from what I've heard) and was quoted $1,000 from a shop in Portland to pull it out and send it to DFIS and then re-install it.
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They quoted me $250-$275 to just put a seal kit on it OR $575-$875 to do a full overhaul and adjust it.
 
So I'm finally getting around to this job. We just had our first baby at the end of October (it's a boy!) and the time I have/want to devote to wrenching is more limited. I've got some time off for the holidays and thought I'd try to tackle the fuel pump problem.

I changed out the fuel filter housing - no more leaks there. Then my battery was dead. Put it on the charger for 24 hr and still nothing. So I replaced the battery after having it tested. After putting in the new battery it would crank and crank but still struggled more than it should. It started twice over a two day period of fiddling with it. I thought it may be an ignition switch problem so I took that apart and found nothing suspicious there. It struggles to start, and then when it's running it won't shut off when I turn the key. I think it's the fuel cutoff solenoid on the back of the pump. I think it's sticking closed when I try to start and then once it's running it's sticking open. When I turn the key to the on position, the solenoid is getting voltage so I know it's not a wiring issue. I found a replacement solenoid on ebay (https://www.ebay.com/itm/183512744076) but when I tried to get my wrench in there to turn it there isn't nearly enough space. So I'll just have to do it once I have the pump removed.

Today I started removing all the hoses, cables, wiring from the injection pump. I still need to rent a pulley puller in order to actually pull the pump off. One of my leaks is coming from the back of the pump, in the center of where the four fuel lines run out to the injectors. Replacement of that o-ring requires an odd, triangle shaped socket. I was wondering if anyone in the Portland metro area has done this job and has that special socket. If so, could I borrow it? I found one on UK ebay but it wouldn't arrive until mid January. Here's an image of what I'm looking for (the one on the far left):
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Update:
Finally got the pump out. Decided to just replace the seals that were leaking: the two o-rings on sides behind the plates of the timing control cylinder, the o-ring for the center plug seal, and I did the front main seal while I had access. I ended up renting the 24mm triangular socket from dieselgeeks.com and had it in two days. I also replaced the fuel cutoff solenoid on the back of the pump. Turns out that was the starting (and not stopping) problem as suspected. The plunger was sticking even with voltage applied. Once it was all put back together and installed, I lined up my timing marks for the camshaft and injection pump sprockets...but failed to check the crankshaft timing mark :eek:. I assumed it was still in line with the camshaft sprocket but it definitely had moved. Didn’t know that until I tried starting it. I blead the air out for the fuel lines by cracking the fuel lines open at the injectors. Once fuel dribbled out I closed them up and started cranking the engine to start. It finally fired up but with some “excessive” Diesel engine clatter. And the sound was coming from under the valve cover. After shutting down the engine I peeked through oil filler opening to see a chunk of metal. Pulled the cover off and discovered 3 broken intake rocker arms.
Lesson learned on the importance of checking engine timing and a new problem to fix.
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Well, shit.

Before reassembly, install the rocker shaft on its own (no rockers) and check that you can torque the 5 retaining bolts to the correct torque, and that none of them feel "soft" as they approach the final torque. When the valves hit the pistons they can lift the rocker shaft and shear the threads in the cam caps, pulling the alloy threads right out. It's an easy and cheap fix with a heli-coil kit if any of them are damaged.

Also check the rocker shaft for bending, cracks, or other damage.
 
Growlerbearnz said:
Well, shit.

Before reassembly, install the rocker shaft on its own (no rockers) and check that you can torque the 5 retaining bolts to the correct torque, and that none of them feel "soft" as they approach the final torque. When the valves hit the pistons they can lift the rocker shaft and shear the threads in the cam caps, pulling the alloy threads right out. It's an easy and cheap fix with a heli-coil kit if any of them are damaged.

Also check the rocker shaft for bending, cracks, or other damage.
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Thanks for the tips. I'll look into the possible sheared threads in the cam caps when I have to time to work on the install. I didn't notice any other cracks on the other rocker arms and the rocker shaft didn't look bent.

For anyone in a similar situation, I was able to order the rocker arms from a dealer in Taiwan through Alibaba for only $3 apiece +$ 30 shipping and it was here in 4 days (there were no slower/cheaper shipping options available when I placed my order). The mitsubishi part number for the intake rocker arm is MD324966. If you need the exhaust rocker arm they have that too for the same price and that mitsubishi part number is MD324967. The dealer is called "Lu Chou Machine Co". Very quick/responsive to inquiry and shipping. Also, for any others needing the valve cover gasket I found it on Amazon, and all the major auto parts stores in the States cary it. It's made by Fel-Pro and the part number is VS50100R. It includes the gasket and half moon seal. The grommets are sold separately but also made by Fel-Pro and the part number is ES70342.

@Growlerbearnz - I found your post on the Canadian forum about rocker clearance. If I adjust it cold to 0.15mm, how do I warm up the engine in order to readjust to 0.25mm without splattering oil all over the place? Just temporarily place the valve cover over it until it's warm? I don't want to seat a new gasket just to pull it off and readjust the valves clearance, right?
 
DeezNuss said:
I found your post on the Canadian forum about rocker clearance. If I adjust it cold to 0.15mm, how do I warm up the engine in order to readjust to 0.25mm without splattering oil all over the place? Just temporarily place the valve cover over it until it's warm? I don't want to seat a new gasket just to pull it off and readjust the valves clearance, right?
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This post, right? The rocker cover gasket is fine if re-used, as long as you clean any oil off the gasket or mating surface and don't overtighten the cover bolts. If you're concerned though you could use the old gasket?
Set your clearances to 0.25 cold (0.15 is only for later engines), reinstall the cover, go for a drive until the temperature gauge is about normal, then check the clearances again.
For bonus points, once you've got the clearance set hot, let the engine cool down and measure the clearances when it's cold- then you'll know what to set them to in future when it's cold. (I bet the difference is minimal though).
 
Growlerbearnz said:
This post, right? The rocker cover gasket is fine if re-used, as long as you clean any oil off the gasket or mating surface and don't overtighten the cover bolts. If you're concerned though you could use the old gasket?
Set your clearances to 0.25 cold (0.15 is only for later engines), reinstall the cover, go for a drive until the temperature gauge is about normal, then check the clearances again.
For bonus points, once you've got the clearance set hot, let the engine cool down and measure the clearances when it's cold- then you'll know what to set them to in future when it's cold. (I bet the difference is minimal though).
Click to expand...
Yep, that’s the post I was referencing. So I got the new intake rockers on, snugged down the bolts to secure the rocker shaft to the cam caps - the threads were in good shape. Got the valve clearance adjusted, cover installed, TRIPLE CHECKED THE TIMING MARKS and it fired right up! However, as I let it idle in order to warm up to readjust the valve clearance, the RPM slowly began to drop. I assumed it was just cold and needed some encouragement so I feathered the accelerator to keep it idling. Even when I held the throttle in the same place the RPM continued to decrease. Eventually it stalled out. Here’s a video of the symptoms
I’m wondering if it’s a fuel filter problem? It was changed about 5500 miles ago. Clogged injectors? I was thinking of replacing the fuel filter and running a can of Liquimoly Diesle Purge through it.
 
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That's a new one to me.

My first suspicion would be all the things you've worked on/changed- it's possible an O-ring is pinched, or the new filter is allowing air into the pump.

I would first check the IP inlet and outlet banjo screens for debris, just in case you've released a bunch of crud into the IP.

Then I would try running it from a jug of diesel directly to the IP's inlet. That'll eliminate the filter as a source of trouble. If you also replace the rubber hoses on the IP's outlet and injector spill rail with clear PVC you'll be able to see if there are any air bubbles, and where they're coming from.
 
I think it is sucking air in somewhere.... the typical symptom is it starts fine and then stalls out after a bit/short drive. It's not really the air that's the problem, but rather the vacuum leak that prevents the pump from supplying enough fuel.
Best scenario is the system wasn't bled well enough... I would probably start with an external tank (jug) to IP.
 
I was able to try the jug method, bypassing the fuel filter. I ran a partial can of Diesel Purge through it (maybe 3-4oz of what I had) with some diesel in my jug. It ran much better - idled at the appropriate RPMs seemingly indefinitely. However it would periodically drip maybe 100 -200 RPM and then restablize. Then when I slowly increased the throttle it peaked around 2100 RPM and slowly began to drop RPM on its own, even as I had the throttle wide open. If I let off and let it struggle a bit the engine speed would eventually stabilize to the more appropriate idle speed. Any chance the governor got outta whack? Would that be a symptom?
 
I'm guessing it's the IP and has to do with one of the seals you replaced...
 
In case anyone was wondering, I finally got this issue resolved. I pulled the pump again and had it rebuilt and timed. Installed and it's running like a champ again. Maybe I was playing whack-a-mole with leaky seals and a full rebuild did the trick. Anyway, glad that this saga is complete. Here's a quick recap:

-New battery (old one was toast)
-New fuel filter housing (it was leaking from the priming plunger)
-Three new intake rocker arms after shattering them from not setting timing properly
-New fuel cutoff solenoid
-Rebuilt fuel injection pump
-Replaced rocker cover. Mine cracked when tightening the original. I had the convex washer for the bolt flipped the wrong way, causing it to crush down instead of the torque wrench to sensing the proper 4-5 ft.lb.

Thanks to all who chimed in to help diagnose, troubleshoot, and give tips. I'm so glad this community and forum exist. It's great to be on the road again!
 
Thanks for the follow-up and letting us know how it went. I'm having the same issues with really rough starts and looking to replace the filter housing, injectors, and hoses first before looking into seals/rebuild on the IP. Where did you end up getting it rebuild? All the diesel mechanics near me won't touch it.
 
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