Itaintez

I hate a thief!!! I'm on the interstate from Nashville,TN to 55 miles west of Nashville everyday. I'll keep my eyes open for it. I always notice clean 12 valves like yours. Good luck!

Well, injectors checked good, so I got a new vp44. While I was at it, I installed a set of RV275 injectors, replaced crossover tube orings, replaced the pushrod cover gasket , intake gaskets, return line fuel seals on the back of the head and adjusted the valves. I haven't gotten to drive it yet, but man that ole cummins sounds good! For future reference, I had no codes leading to a bad vp44. Thanks guys for all the suggestions.

Yep, They told me $6.50 each to test injectors.

Tonight I took the fuel supply hose off the steel line under the cab and put it in a 6 gal can of diesel. I started truck up and got the same stumbling/miss as before. Next I removed the supply hose from the lp inlet fitting and installed a new hose and clamped it to inlet fitting, this eliminated the quick connect fitting like you see on gasoline fuel hoses. also I stuck the new hose in the diesel can, started truck up, same results, stumbling/missing. I tried lowering fuel pressure and this didn't help either. Question: Would it benefit me to install a clear hose between the filter housing and the lift pump. I know that side should be pressure and not suction and I'm not leaking any fuel there or anywhere. My next step will probably be removing injectors for a pop test and if they're good ,on to the vp44, sound logical?

You are right @dripley I have not ruled out air in system. I've opened filter drain while running and cracked inj lines to look for air. I plan to do a bucket test from lp inlet and work forward with clear hose. I'm just pricing parts to get ideas if my pump is bad. The rebuilder I called is Dixie Diesel in Columbia,Tn. I called back to verify they have an 815 Bosch test stand and he verified they do and are one of few that do. Mike you can add Them to your list.

Just talked to a diesel shop here local. $1395 for rebuilt pump with new electronics and 2 yr warranty. Does that sound like a fair price? I asked and he said they do rebuild the vp44 pumps. I asked about upgraded injectors and he said $72 each. Would I see much power increase from bigger injectors with a stock pump?

Exhaust temps coming out of exh ports at manifold are within 40deg from the least to the greatest at idle. If i had an injector not contributing, wouldn't I see that in a substantial drop in temp on that cylinder? Yes, as far as I know the injectors are stock. Vp44 has a reman sticker on top of it. It was this way when I bought the truck 5 yr ago. As far as key being off, I doubt it, it ran fine for five yrs.

You can put the truck in gear and take off and as long as it's accelerating it runs normal. It will sound like the video on deceleration or at idle. If it was air in the system would it still run good under a load?

Video of my truck running with the vp44 hotwired.

Here is the youtube link to the video of my truck idling.

Yep I did the hot wire test, the idle is about 900 . I'm not as concerned with the idle speed as I am the engine missing like crazy. Engine is still stumbling/ missing like crazy even when hotwired. So this means vp44.is bad, correct? Also I've checked for air at inj lines and I've got good fuel pressure spraying out when running. I've got some videos of the truck running. Is it better to post YouTube then share the link?

Anybody got ideas on my vp44 being bad from the tests I've done?

I got the wires on the vp44 that go to the timing solenoid covered with heat shrink. Started up the truck and it ran normal with no missing for about 8-10 mins, then the miss came back. Today I hot wired the vp44 and started it up. I still have the miss and if anything maybe just a touch worse. Does this mean that my ecm is out of the equation as far as the missing goes and that the vp44 is the reason for my rough idle?

I don't think you can adjust a factory apps like this method. If you have the timbo aftermarket apps, then yes you can use that method.

Had a few hrs today to work on my truck. The ect was 60 deg and the Iat was reading 58.7 deg on cold startup. I recalibrated my timbo apps and started my truck. Same results, went to 1k rpm, idle ran smooth for about 20 sec then started missing and cutting out. I was watching rpm on scanner and it was fluctuating from around 920 to 990. I accelerated to about 1800 rpm and let off and it was still fluctuating. I printed off the troubleshoot guide from bluechip diesel and proceeded. I started with the vp44 connector. When I unplugged it I noticed 2 wires from the comp board on top were smashed in between the vp44 connector and the pump housing so I moved them up out of the way. I proceeded to check the pins in the pump connector, voltages were good except pin 5 had a very slight .107v while engine was running but when shutdown it went to 13v for a few seconds then voltage went away as it should. What I did notice is that the truck idled at 950 rpm and it was smooth!!! No missing!? I let I run for about a min and shut it off. I checked the two wires on the pump I had moved and noticed the outer covering on the wires deteriorated and cracked all over. When I touched the wires, the insulation fell off!!. Now I'm trying to figure out how to cover the wires. I"m thinking cut the wires, put on some heat shrink tubing and solder the wires back together? I believe these 2 wires are for timing fuel on the pump. They run towards the eng block not the 2 that go between the fuel lines. Anyone ever solder these before?? Sorry so long.

What did you find out on your truck? @Mose705

Thanks notlimah. Got it now.

I have a temp gun and will check temps for differing temps. I believe Iat and ect were the same on cold startup but will check again. According to scanner apps is picked up after pressing slightly on accelerator pedal ,but i will check voltage at the harness to verify calibration. Thanks for advice and I will post results as soon as I get them. Newbie question, how do I fill out my profile to show my truck specs?

My coolant temp is reaching 190 deg. Ect sensor is reading properly on scanner an I even swapped ect to see if it changed the condition and it didn't . I run fleetguard fuel filters. Filter has 1k since changed. I took filter off to check for water and contaminants and it looked good. Iat sensor is also showing good temps and I even swapped to see if I got a change and did not.?? Any thoughts, suggestions, tests? I'm willing to test whatever to fix my cummins!

Newbie here so please be gentle. I have a 99 24v, 4x4 auto 134k miles that started idling at 1000 rpm's and has a miss to it. Happened out of the blue while wife was driving. Idle stays at 1k and misses unless put in gear. when put in gear, it idles @ 900 rpm and smoothes out under load of trans while in gear. Truck runs out great as long as its accelerating but when you let off throttle you can hear it miss. Fuel psi is 19 at idle with a air dog 100 lift pump. Truck is stock besides lift pump. Only code its giving is p0234 and I found waste gate stuck. All exh temps from exh man are within 40 deg f of each other. Iat, ect , and map look good on scanner. Batteries are 6 months old and test good. I have checked and cleaned grounds. I have a timbo apps about 1 year old. Truck doesn't smoke any out exh pipe. I checked for ac voltage and got a high of .030vac. Any ideas? What will make a cummins idle high? ecm? I have auto enginuity on my laptop to scan with. Please help!