Sounds like a misfire please help!

[Keith_J]

DB 2829-4521 is a CUCV IP. Specifically, a 1.2 centi Stoke JP8 rated pump for 1986 calibration. It is a 12 volt unit.

It is a replacement unit as 1986 came with a 4520, the only difference being the low viscosity wear parts.



Since the vehicle is a 1984, the original pump used the flex ring, all military replacements were 4521 calibration as this model doesn't use the flex ring.

 

[Keith_J]

From the second video, I hear diesel clatter and a lot of it. Timing may be stuck, this happens with wear in the aluminum case. Does the engine smooth out at idle when the light load advance button is pushed in? Use a long screwdriver as this is on this bottom passenger side of the IP.

 

[Domterry12]

From the second video, I hear diesel clatter and a lot of it. Timing may be stuck, this happens with wear in the aluminum case. Does the engine smooth out at idle when the light load advance button is pushed in? Use a long screwdriver as this is on this bottom passenger side of the IP.

I will test once I get home. But I believe it does. When jnfirst got truck I tried the advance and it was sticking, but I worked it with some penetrating oil and it’s free Now….

u saying timing may be stuck could be because yesterday I changed IP timing on a big swing; and absolutely no change in the way it ran . How doyou “unstick” timing?

 

[Keith_J]

If the timing is stuck, it is because of wear in the aluminum housing. Some rebuilders machine and sleeve the bore.
Because you have a 4521 pump, it was probably a government shop rebuild and the TM doesn't cover sleeving the cylinder when worn.

The photo on the first page looks like timing is way off.

 

[Domterry12]

If the timing is stuck, it is because of wear in the aluminum housing. Some rebuilders machine and sleeve the bore.
Because you have a 4521 pump, it was probably a government shop rebuild and the TM doesn't cover sleeving the cylinder when worn.

The photo on the first page looks like timing is way off.

@Keith_J so a new IP would solve that. I’m gonna go test the advance right now and I’ll take video….I know the timing looks way off in the pic but yesterday I tried to advance the timing and the pump maxed out in the slots, physically couldn’t turn the pump any more and the lines weren’t matched up yet.
I think my pump is a rebuild and somehow the timing mark on pump is way off. Also I have red paint on IP bolts to show a seal wasn’t broken, and I don’t think that was factory.

 

[Keith_J]

I sense this was a depot rebuild of the injection pump. There are 3 levels of maintenance, unit level like company or battery which is covered in the -20 TM, direct support which is battalion or brigade covered in the -30 and depot which is covered in the -40. Most TMs are multiple level, the -34 covers direct support and depot.

So, this pump was removed at the DS level and the SMR code is PAFHH. The P and A mean it is a regular part. F means direct support is the level which can replace it. H H means general support overhaul and dispose at GS if not rebuildable.

There is a line item for 0.002" over size piston bore case but no sleeves.

You can call me CPL Bowers, Army Librarian.

SMR is source, maintenance and recoverability.

 

[Domterry12]

well all this knowledge is most appreciated. So as u can see in video, when I push advance in it stumbles down and idles rougher and lower and I get grey smoke from exhaust….but the button that the lever pushes in sticks in the IP upon release, so I WD40’d It and worked it in and out but it still seems if I push the advance all the way in, and release, it’s only releasing half way if I’m lucky. What ya think?

 

[Keith_J]

Try some Diesel Mechanic in a Bottle. The button seals can be replaced without IP removal. If the button sticks, it messes the timing and this is probably the issue.

Timing sounds correct at idle. If it still stumbles with the pin free, you need an overhaul IP. Some rebuilders do the sleeve so shop around.

 

[Domterry12]

Try some Diesel Mechanic in a Bottle. The button seals can be replaced without IP removal. If the button sticks, it messes the timing and this is probably the issue.

Timing sounds correct at idle. If it still stumbles with the pin free, you need an overhaul IP. Some rebuilders do the sleeve so shop around.

It does not stumble at idle with the pin free. I guess when the pin is sticking it’s causing my issue. I’ll try and look up replacing those pin seals but probably just gonna change the IP

 

[Domterry12]

Injection pump ordered. Will update when new one is installed. My fingers are crossed

 

[Domterry12]

@cucvrus @Keith_J ok here’s an update guys. Don’t think it’s too good. So over the past week I swapped the IP. Finished this morn, cranked it over with loose lines on the injector till I got fuel, tightened the lines up. Timing mark a hair to the driver side. Started it up and held the RPMs up to purge any air. Now truck is warm and here’s what it does.
Runs crappy. If I shut it off it’s a hard start and have to give it some pedal. Once it’s running, it idles pretty well. If I give it throttle, it bogs a little then picks up. If I keep it steady at let’s say 2k rpm, then I take my foot off it it stalls.
Please say it’s timing. Please don’t say it’s a bad IP. IP is a rebuild 4544 and the plate on the side is dated 8/22 so fresh rebuild . What’s the best way to time it I don’t have a timing light. How do I do it by pushing the cold advance in?

 

[ezgn]

@cucvrus @Keith_J ok here’s an update guys. Don’t think it’s too good. So over the past week I swapped the IP. Finished this morn, cranked it over with loose lines on the injector till I got fuel, tightened the lines up. Timing mark a hair to the driver side. Started it up and held the RPMs up to purge any air. Now truck is warm and here’s what it does.
Runs shitty. If I shut it off it’s a hard start and have to give it some pedal. Once it’s running, it idles pretty well. If I give it throttle, it bogs a little then picks up. If I keep it steady at let’s say 2k rpm, then I take my foot off it it stalls.
Please say it’s timing. Please don’t say it’s a bad IP. IP is a rebuild 4544 and the plate on the side is dated 8/22 so fresh rebuild . What’s the best way to time it I don’t have a timing light. How do I do it by pushing the cold advance in?

It does not sound like timing to me. If your timing mark is close to both timing marks lining up it should start and idle fairly well. I just set the marks on top of each other and test drive. You should end up with the timing marks some what close together. There is a tool you can make to set it up by the book, but it isn't necessary in my opinion. Re-set the timing again in a new position and retest. If you can't get any improvement then your problem is else where. The tool I am refering to actually sets your vcv valve for your vacuum. The timing is set by moving your injection pump.

 

[cucvrus]

1986 CUCV M1009 Decade after being wrecked. | Page 35 | SteelSoldiers
I looked back at my previous notes, and I noted that I moved the injection pump timing line 2-line thicknesses to the driver's side of the line-to-line timing of the injection pump. I see yours is to the passenger's side. I used a strap wrench to move the pump over and it ran perfect. Could you try that and report back?

Did you try to move the injection pump to the driver's side 2-line thicknesses? You have nothing to lose. I thought it was crazy and I done it on my M1009. It ran perfect.

 

[Domterry12]

Did you try to move the injection pump to the driver's side 2-line thicknesses? You have nothing to lose. I thought it was crazy and I done it on my M1009. It ran perfect.

Yes that’s were I set it initially when I installed the pump. And it runs like crap. Stalls if i goose the pedal. Hard starting. Running worse than the original pump lol

 

[cucvrus]

OK. That worked for me. May not work for you. Experiment with it. See where it runs the best. Move it a small bit at a time.

 

[Keith_J]

If pushing the light load advance button causes stumbling, timing is correct. Keep advancing timing until pushing the button causes stumbling.

Indirect injection is more tolerant of timing. But you could have a loose timing chain.

 

[ezgn]

If pushing the light load advance button causes stumbling, timing is correct. Keep advancing timing until pushing the button causes stumbling.

Indirect injection is more tolerant of timing. But you could have a loose timing chain.

Your already well past the timing mark. With a new pump you should be able to line up the marks. Start there and see what you get. You can advance the timing more than is necessary, but the engine will run louder and result in higher RPM's. No need to try and push more power out then necessary. Save your motor and your ears.

 

[Domterry12]

If pushing the light load advance button causes stumbling, timing is correct. Keep advancing timing until pushing the button causes stumbling.

Indirect injection is more tolerant of timing. But you could have a loose timing chain.

I’ve just adjusted the timing on the new injection pump to where it stumbles with the light load advance pushed in and now it seems to start with ease, idles good. But if Its idling, i push that pedal and let it go. It stalls. Every time. Same if I drive. I take off, let go of gas to hit brake. It stalls. This didn’t happen until I changed pump

 

[royalflush55]

Are you still using known clean fuel in your can or did you hook it back up to the stock tank that could have bad fuel?

 

[Keith_J]

I’ve just adjusted the timing on the new injection pump to where it stumbles with the light load advance pushed in and now it seems to start with ease, idles good. But if Its idling, i push that pedal and let it go. It stalls. Every time. Same if I drive. I take off, let go of gas to hit brake. It stalls. This didn’t happen until I changed pump

Sounds like a sticking metering valve.

In the far past. I used Berryman B12 spray cleaner to remove the varnish on metering valves. It works BUT it must never be used through the pump or into the engine. Now I use Diesel Mechanic in a Bottle, just as aggressive as the acetone-methanol-toluene of B12 yet can be used through all parts of the injection system. For DB2 metering valve, take the 3 screws off the governor cover, remove as much fuel and replace with Diesel Mechanic in a Bottle. Flip the metering valve a few times and let it sit overnight.