blueberry

wannadiesel,

Pickup assembly & tank were inspected yesterday afternoon and everything looked good. The past 2-3 fillups did not make the problem go away. The truck just didn't have much in the way of power. I pulled the pump and will take it to the diesel shop tomorrow so they can test it... I'll let ya'll know what they find.

Brian

flashgordon

I'm with G1625S on this one. Some how i don't think it's the inj pump ether!
if it's run for a hour with out problem it should run for a long time,......evan with pour filter changing habits!


air is more likely the the problem!


get a long piece of clear plastic line and tap it in between the lift pump and were it connect at the frame rail. Bleed all the air out of every thing and start it! if you get a lot of bubbles going thru the clear plastic hose, you have found the area that need attention, to fix the problem!

If not just make sure the connections or tight and drive it till it act's up again. Raise the hood and see if it's air.
when the hood is shut, i like to coil the clear plastic line around the master cylinder, tends to stay out of the way there.
If you only have a problem at say....half a tank or lower then i would suspect the tank module, that Dave suggested above!

blueberry

I considered air in the line as a possibility but it does not explain all the fuel dumping out of the #2 injector line. That is what convinced me to pull the pump. I will let ya'll know what the shop says. I will keep the advice for testing for air in the line handy in case I need it in the future.

Thanks,
Brian

blueberry

Hey all,

The local diesel shop said the pump is in very bad shape and wants $1704 to rebuild it. They were not sure why it may have failed. They made varying suggestions that it could be anything from the fact that Cummins remans their pumps south of the border to the fuel I use. I asked them about the fact that the pump timing was off one tooth for a few weeks and they said that could be it too. Their suggestion was to get a core in better shape that they could rebuild.

Anybody have a good core they want to part with? I can travel within a few hundred miles of Nashville or Bristol if someone has one but doesn't want to ship it.

Brian

G1625S

Wow...that really sucks! The timing being off causing problems is total BS---the pump doesn't care when it fires the injectors. The only thing that affects the pump is an injector that is set at too high a pop pressure. I hope you can find an affordable solution...and have those injectors pop-tested, just to be safe...
greg

blueberry

I just want to set it straight that the shop did not suggest timing problems as a cause of failure, I asked them. They didn't seem to think it was a big deal. The reason I asked was because I have read on here when the timing is too high that the pump can make metallic noises. Here is the complete history:

October, 2005 - Diagnosed AFC problem. Purchased reman pump and injectors from Cummins. Installed with help of TDR member. Injectors pop tested at 3900 psi at shop in SEMO.

March, 2006 - Got tire of turbo lag. Started adjusting timing. Had shop in TN bench test pump and set it 10% hot. Knowing how to do it, I R/R the pump myself.

April, 2006 - Questioned blue haze in cooler weather. Injectors pop tested at 3300 psi shop says they're not the problem. Buy dial indicator, says timing is nearly 2.5 mm. Reset timing to 1.65 mm.

May, 2006 - Use dial indicator to set timing to 1.4 mm. Seems to get a little better fuel economy.

~ Drive 10-15K miles ~

October, 2006 - With the onset of cooler weather, experience low power and engine surging 2nd weekend of October. Seemed to go away with truck stop tank top off and additives, unsure if diesel was starting to gel. Problem comes up again after I fill up local gas station diesel and goes away after truck stop tank top off and additives. Drove about 750 miles since first experienced low power. Next 300 miles seems fine so maybe just some junk diesel or smaller non-truck stop stations have summer fuel. Third week of October, low power cold Friday morning. Change fuel filter, was dirty. Drive 300 miles OK. Saturday morning have low power on one hill at 60 MPH but otherwise fine. Sunday low power and does not ever get better. Pump failed Tuesday, and removed. Dismantled Friday.

G1625S

Oh, ok. The extra noise from advanced timing is actually the bang in the combustion chamber happening earlier which makes the noise louder. AFAIK, the only thing that will make the IP itself louder is the injector pop pressure, which you already have covered. I imagine your lift pump is either new or is putting out good pressure? Again, I'm very sorry for your troubles--I hope you find a solution shortly
greg

blueberry

The lift pump was replaced before the AFC problem was diagnosed so it should be working just fine. I don't have a regular fuel psi gauge.

Brian

Field_boss_cb

I see one that was doing something close to what you are experiencing. We had a time trying figuring it out. It was the front bearing wearing out in the transmission. Finally locked up and spun in the case.

DJ

What kind of warranty did you get with the year old rebuilt IP??

blueberry

The Cummins reman reubild was 6 months unlimited hours. The local shop said $1704 for a rebuild because the advance piston was stuck in the housing. I saw the worn rollers and cam plate, they definitely needed to be replaced. I didn't think their price was reasonable so I called two other shops who confirmed they've never changed a housing for a stuck piston. I sent it to one of the latter shops and it cost $600.11 to rebuild including cam plate, rollers, some nuts and bolts I forgot to send. They said the advance piston came right out.

I am still having problems with low power. The truck should do better than 60 MPH with no trailer on the country road to my house in 4th which is all it does... sometimes. Max boost is 14 psi and the timing is 1.6 mm with a dial indicator. It generally does OK on the freeway. I am wondering if I am sucking air, I am going to splice in a clear line to see and/or replace the in-tank pickup and fuel line if for nothing else just to eliminate the possibility in the future.

dpuckett

Do you have your pyrometer set up yet? If so, what is your peak EGT? 14 sounds a little low for 10% over stock (about 80-83mm/stroke). You could have a boost leak and be running 1400deg at cruise. I wonder if your AFC line isnt broken, cracked, or pinched off? Are there any witness marks on the AFC pin? Hope you get it figured out. I'd hate for you to have to bring it to me for a week, as I'd most likely void any warranty you had.

Daniel

blueberry

I've taken the AFC housing apart and as I recall it looked good. They adjusted it to a different position than originally and its making a new mark. I dont' think they care much about tweaking in terms of warranty, but I doubt its a pump problem. I bought some fuel hose and am going to do away with that factory suction line. I also ordered a new in-tank pickup but part of me just wants to do away with the hole mess and get a 100 gal tank for the bed/flatbed.

blueberry

This afternoon in the cold, wet gravel I changed the fuel suction line between the in-tank sending unit and the lift pump. It was not much fun trying to get those quick disconnects apart with the limited room between the tank and the bed. I used transmission oil cooler line as this seemed to be better chancing regular fuel hose. So far, so good. I'll see how this runs, hopefully it will make a difference.

Brian

blueberry

Well the truck is still not running that great. I am going to try double check with the clear plastic fuel line just before the lift pump to see if I see any bubbles.

I am just confused as to the boost pressure. When the truck is running poorly on the freeway it will say 5 psi of boost on level ground or downhill at 72 MPH. When its running better that number is lower, maybe 2-4 psi.

I am not sure that bubbly fuel would do this? I am wondering if the previous note about a warn front bearing in the transmission is causing a drag on the engine.

I really don't want to pull the Getrag, because that also means pulling the NP205 but maybe I should??? Can I inspect the bearings in the trans without removing the transmission?.