Looking for second opinion on low power

[SGT Estum]

After much thread searching, I think I've devised a sequence to troubleshoot my issue but I'd love a second opinion on my methods. I'd like to make sure I'm not doing extra stuff that doesn't matter or doesn't make sense.

So a while back I had an abnormally large puddle under my M1009. I saw fluid dripping from the frame cross member under the engine. It was black but it smelled of diesel, which made sense since I had been mixing filtered waste motor oil (WMO) in with my diesel for a while. I tried to trace the leak and decided it was likely coming from the lift pump and/or the rubber hose connected to the lift pump. So, I replaced the lift pump and hose.

I couldn't find the preformed fuel hose, so I used about 12 inches of 3/8" I.D. fuel line and wound it in there like the OEM hose. I installed everything, bled the fuel lines at valve on top of the fuel filter base (per the TM) and started it up.

Shortly thereafter I noticed a significant lack of power. Unfortunately, I couldn't remember if it drove like that before I changed the lift pump and fuel line or not. But I definitely notice it now.

I searched threads and inspected my engine. I noticed the first injector on the driver's side was quite wet and suspected that I may have a bad/stuck injector. I was about to take it off and have it pop tested but then I noticed a slight kink in the fuel line out of the lift pump.

So my plan is this (here's where the feedback comes in):
1. Install a fuel gage on one or both of the lines coming out of the right hand side of the fuel filter. Check to make sure good pressure is coming out of the lift pump -- if there isn't, then I know the fuel line is too kinked and I'll need to come up with something else for that line.

2. If there IS good pressure, then pull all the injectors and have them pop tested. This will get me new return lines and seals.

3. If the injectors all pop well, pull off the intake manifold and proceed to remove the injection pump. IP will need rebuilding.


Am I on the right track here?

 

[91W350]

I had the same problem when I used the 3/8ths hose on my first M1008 and it was sucking the hose flat, effectively shutting down the fuel in one of the bends. I finally cured it by sliding the hose into a section of heat shrink, then shrinking the heat shrink on the hose with a heat gun. It would not curl as tightly as before and I placed it inside some of that split flex tube they use for wiring harness. Glen

Editing to say I would suspect that flat curve you show in photo six. It looks collapsed right there by the engine mount.

 

[SGT Estum]

I had the same problem when I used the 3/8ths hose on my first M1008 and it was sucking the hose flat, effectively shutting down the fuel in one of the bends. I finally cured it by sliding the hose into a section of heat shrink, then shrinking the heat shrink on the hose with a heat gun. It would not curl as tightly as before and I placed it inside some of that split flex tube they use for wiring harness. Glen

Editing to say I would suspect that flat curve you show in photo six. It looks collapsed right there by the engine mount.

Hmmm.. I hadn't thought of heat shrink tubing. I was going to try to jerry-rig something similar with garden hose but it didn't work out so hot.

I'm still considering the pressure gage, because I'd like to know for sure that the hose by the lift pump is the problem before I start tinkering with it. Working down by that lift pump is a real pain.

My main concern is getting all the air out when I break open the line coming out of the fuel filter base.... or maybe I don't fully understand how the bleeding works.

 

[ohfisherman]

you are gonna have to bite the bullet and try to find the preformed hose. any 73-87 c-k series truck with a v8 should work...

 

[TCUCV]

I agree with fisherman . . . have you tried shortning the line so it won't get kinked?
good luck on your fix!

 

[SGT Estum]

I've eliminated the kink in the fuel line by the lift pump. I know the OEM part would have perhaps been better, but I needed some immediate gratification.

I used two right angle brass fittings with pipe thread on one end and a barb for 3/8" I.D. fuel line on the other. I coupled them with a female-female connector and some teflon tape. A few hose clamps and a short run of fuel hose and I've eliminated the kink. Cost for the parts was around $20 which is less than I would have spent to get that fuel pressure gage installed. Not sure why I was infatuated with a fuel pressure gage, but whatever...

I bled at the knob on top of the fuel filter base then started it up. I took it out for a test drive and it performed exactly the same. So, I can eliminate the fuel hose on the lift pump as the issue.

 

[SGT Estum]

After my test drive, popped the hood to check everything out. Again, the first injector on the driver's side appeared wet. It seems to have fuel pooling up by the steel line. It looked like there were tiny bubbling going on in the fuel puddle.

I wonder if that #1 injector is stuck closed and the pressurized fuel is seeping out or something. I see a 30mm deep well socket purchase in my near future.

 

[Disciple]

I'm having very similar issues with my M1008. Running WMO, low on power, etc. Now it won't start. Cranks and white smoke. Replaced fuel filter and lift pump (looked like it was leaking). Same issues. Siphoned tank and replaced with fresh diesel, bled system, no go. Really hoping I didn't burn up something expensive (injector pump). Any tips guys? Should I pull each injector and bleed there?

Sorry to hijack, but Estum, I live in Burnsville and known two others in the area with CUCV's. We could have our own rally! Assuming of course that we can get these things to run right.

 

[Barrman]

Estrum,
That line is loose at the injector. Use a 3/4 open end to just snug it a little bit tighter. Have you pulled the return line fitting from the top of the IP and checked to see if it is clogged? Clean that out if it is plugged and it should run great again. Of course, that being clogged means your IP is killing itself and will need to be replaced soon. If it isn't plugged, run the return line to another source and see if the truck runs better. I am thinking a kinked return line as another option.

 

[SGT Estum]

Estrum,
That line is loose at the injector. Use a 3/4 open end to just snug it a little bit tighter. Have you pulled the return line fitting from the top of the IP and checked to see if it is clogged? Clean that out if it is plugged and it should run great again. Of course, that being clogged means your IP is killing itself and will need to be replaced soon. If it isn't plugged, run the return line to another source and see if the truck runs better. I am thinking a kinked return line as another option.

I forgot to mention I tightened the steel line at the injector about a week ago with a 3/4" wrench. It felt pretty darn tight.

I have not looked into the return line at the top of the IP yet. Is that where the infamous glass ball check valve is? I've read several posts mentioning this check valve but I have yet to locate it.

I'll check out the IP return line stuff this afternoon.

 

[Barrman]

Put a 7/8 on the injector and then give it just a hair more with the 3/4. If the injector moves, undo the line, tighten the injector and start over on the line.

Yes, that is the glass ball fitting. Any trash or gunk in there means the IP needs rebuilt. It is on top, has a rubber hose going toward the radiator and probably has a red squeeze clamp holding the hose on. 9/16 socket removes it.

 

[fox3344]

I also had a low power issue on the M1009, but have finally fixed it. My truck had the white smoke, low power, etc.

I had two problems I believe.

The first issue was the filter in the fuel tank. It's a small "sock" type filter connected to the fuel pick up line. Mine felt almost like a plastic type filter, but was completely plugged with gunk and a wax type substance.

Second, and the main problem, was my fuel injectors. I removed one for inspection and found the tip packed with carbon build up. Needless to say I replaced all eight injectors with rebuilt units. After replacing the injectors it was like driving a new truck!

Hopefully this will give you a couple more ideas to look into. As a side note, I had already replaced the IP in the search for more power.

Good luck and keep up posted.

 

[SGT Estum]

Per Barrman's advice, I gave just a little bit more wrench to the wet injector. Sure enough, that seems to have cleared up the pooling fuel at that point.

I also took off the check valve on the Injection Pump. I used this thread to make heads and tails of where this infamous glass ball is:
http://www.steelsoldiers.com/cucv/47346-so-i-cleaned-ip-valve-fuel-return-line-4.html

I poked around in there with the straw off a can of WD-40 (or similar) and it moved freely and had a nice spring-return feel to it. So far as I can tell, it was quite clean in there as well as in the injection pump. Actually, there was no residue, crud, or super small shreds of gasket/seal/rubber material to be found. I wiped the stuff down then reinstalled it.

While I was in the area, I traced the return line and discovered it leads to a rubber hose that heads back to the fuel tank. Makes sense; but I had never connected the dots before so it was a bit enlightening for me. Just for good measure, I removed the fuel cap, pulled that hose, and blew some compressed air in there to ensure no blockages on the return side. Everything was nice and clear.

I took it out for a test drive and it is still lacking power. I'm back to suspecting injectors now.

I ordered a injector removal socket today -- should get here later this week.


Thanks to all who have posted in response. Gotta love this site.

 

[SGT Estum]

Received my injector removal socket yesterday. A few things came up so I didn't get around to removing anything until today.

The plan was to get these things pressure tested to see if they needed a rebuild/replacement. However, all the injector tips look pretty well destroyed so I think they're getting rebuilt regardless. That said, I've never seen the business end of a 6.2 injector before so...

I've actually only removed six of eight so far because it was getting dark out. So far 5 say "MADE IN USA" and one says "GERMANY". The number in the circle for the German one says 060 while the others say 927 -- any ideas what that means?

Maybe it was in my head, but the ones on the passenger's side seemed much harder to turn than the ones on the driver's side. Any insights are welcome

 

[SGT Estum]

Replaced the injectors with rebuilds. Looks like my power is back!

 

[kentuckycucv]

Glad i found this thread. I too have had a loss of power....I removed one injector and have a little carbon. I cleaned it and put it back in. I am wondering if i could remove all my injectors and clean them if they have the carbon deposits???

 

[SGT Estum]

Glad i found this thread. I too have had a loss of power....I removed one injector and have a little carbon. I cleaned it and put it back in. I am wondering if i could remove all my injectors and clean them if they have the carbon deposits???

I never tried "cleaning" mine. I went straight for rebuilt. It's kind of a pain to take out the injectors and bleed the steel lines so I decided that if I was taking them out, then I was going to put rebuilt in. Also the rebuilt ones were only around $150 or so.

Note that apart from carbon filth, my injectors may not have been popping at the correct pressures. Rebuild injectors are balanced and pop at the same pressures.

If you do try the cleaning method, I'd be interested to know how it works and what you use to clean them.

 

[mr.travo]

SGT E-

Where did you order your rebuilt injectors from?

 

[SGT Estum]

I ordered rebuilt injectors (bosch) from a guy on eBay. The company is called Badger Diesel and they're out of Wisconsin. I suspect you could probably just call directly and order them if you didn't want to go through eBay.

I also purchased new injector return lines from them. The return lines are the type that do not require the little metal clips, but it's a quality rubber with braided cloth over it. Says made in Germany right on it -- way better than that Chinese crap Dorman distributes. It came as one big long line then I cut it to lenghts, which was nice.

 

[mr.travo]

I have been emailing Fred down there and he tells me that I should need the short body injectors with 054 stamped on them. My eyes aren't as great as they used to be, so I can't see what's on mine. Does this sound right? I just wanted to order the right ones the first time.

Thanks!

Oh ya, he said they are reman Bosch's.