M813 Power issues...

[rmgill]

My M813 continues to have some random power problems on acceleration. The characteristics are that it looses power and becomes gutless for about 5-20 seconds and then gains power again. This is about the time that I hit the 3rd to 4th gear acceleration. Sometimes the RPMs stay up and float for a bit then drop back as normal. I was comparing vehicles with two friends yesterday and one suggested that the governor could be sticky.

Looking through the parts -34 and -34p TMs, the governor on the Cummins seems to be sealed under a sealing wire and accessing it seems to imply that if you make changes a re-calibration of the fuel pump is required. Does a simple servicing of this area require a re-calibration? ie If I change none of the shims and just check the operation of the governor weights and such should there be any requirement for a re-calibration on the bench test gear?

Fuel does not appear to have problems. I'm not showing any water any more on pre-driving service. When I was seeing water it was showing about 3-4 table spoons of water. It has a new fuel filter which did have some sludge in/on it. The previous drains of the fuel system showed some of that sludge in with the water. I have not drained the full fuel system. This could be done however.

Could it be as simple as the fuel filter at the fuel pump being partially blocked by some of that gunk. Looking through the -34p that did appear to be an item to check though I don't recall seeing that in the -10 TM.

Thanks!

 

[73m819]

i had the same prob with my 819, i finally steamcleaned the tank, then got 99.9% of the fine rust out, the fine rust was pluging up the filter, i was getting about 50 miles a filter, after doing the tank i havent had to change the filter yet and i have about 600 on it , when i drain the filter i now get clear clean fuel,

 

[Jones]

Here's another thing to consider. Paper element filters will absorb water and once saturated, the paper won't allow fuel to pass through it. Just found out the hard way (after pulling, draining and treating tank interior) that "runs fine at idle and low speed but not at higher RPMs" was nothing more that a partially clogged filter.

 

[rmgill]

I'll do another fuel filter swap then. I'm also going to dig into the fuel pump and swap that small filter.

 

[rmgill]

I think I've solved my power problem issue. I swapped the fuel filter and tried getting at the filter on the fuel pump. Couldn't get into it. The slotted cover just doesn't want to budge so I left that filter there (figure it'll get pulled when the pump is rebuilt).

So, trying to prime the fuel system didn't really seem to want to happen. I'd think I had it primed, run it for a bit and it'd die. So, I dropped that for a bit, drained the filter again and figured I'd need to get the gunk and water in the bottom of the tank that seems to get trapped in the filter. Long brass tube, a bit of water and my vacuum pump to get the fuel going and I started draining water. The truck was at a slight angle so most of the beads of water were at the front left corner. I managed to drain about 3 pints of water and sediment. Clearly that should help some.

Next I pulled the fuel intake at the top of the tank and lo in the pickup tube there were 2 bits of plastic off of coke bottles! That would cause a problem with power no doubt!. I siphoned that area of the tank as well and picked up more gunk and a bit of water. That fuel got time to settle, get filtered to another container and then get filtered again to another before being dumped back in the tank san's water.

Putting it all back together, priming the fuel pump and then starting it up seems to have done the trick. I"ll road test it tomorrow to see for sure. But I'm confident it'll be good.

 

[73m819]

i did all that two, still had filter problems, as i said i finially said screw it , pulled the tank and a friend steamed cleaned it, you would be amased at the gonk and crap that still was in the tank, he stuck the nozzle way up in the conners, i bet crap came out for 15 minutes, since then nothing but clean fuel draines from the filiter when i check it

 

[rmgill]

I might end up doing that. But I really needed to solve this power problem if I'm going to swap it for David's Deuce. I got a good bit of gunk out of there. There might be some left, but it's a much smaller amount. I'll see what the fuel filter shows after I take it out and run around fora bit.

Seems like a nice high volume flow pump hooked up to a filter and two hoses might be a way to make a vacuum for "washing" the fuel. Stick the hose on the end of a bit of 1" tubing an you'd be able to vacuum the tank and clean the fuel with out having to pull it all out. Plus it'd pull out all the extra sediment.

I'll need the kit anyhow since I want to set up a Bio Diesel Reactor.

 

[rmgill]

Took the 813 out today. Lots more power now. And reliably too. Much better. Looks like I'll feel better trading it to David S. too. We've got Tuesday slated for the swap of trucks and some gear.

 

[DrFoster]

Reading this almost makes me wonder if I shouldn't go ahead and install a petcock drain in the bottom of my tank (like the aircraft type that are under the wings) to get rid of all of the water that might show up.

 

[red devils dude]

there is a plug I think, my deuce has one.

 

[DrFoster]

Yes, but the aircraft plug is a push-in type to drain fuel... nothing to remove and have messes