Archived Truck down - need help! Injection pump?

[wilcoxeng]

I have a 99. I stopped at a rest stop and the truck was running fine. When it was restarted it started hard (cranked for several seconds) but then it idled normally. However, it chugged when the accelorator pedal was depressed and had no power. I was able to drive it around the parking lot at idle. I had it towed to the next largest city and replace the fuel filter. Now it starts right up but runs on about 2 cylinders and won't clear out. The truck has 150,000 miles. I put a FASS on at about 100,000. The fuel pressure gauge pegs at 15 psi. It also has an older Edge 50/100/150 and after market injectors. I'm not sure why it won't idle ok now unless their is still air in the system? I have never had this problem with the FASS. Any ideas?

 

[JLandry]

Have you checked for diagnostic trouble codes?



Were any of the lines to the fuel injectors cracked open to try and purge any trapped air?



Where is the truck located? Maybe a TDR member in the area might have a Cummins VP44 tester which could be used to rule it out as the problem.



Good luck,



John L.

 

[wilcoxeng]

Thanks for the response. I am in Davenport, Ia. I am working on getting wrenches right now so I can crack the lines to bleed the air. Is it enough to bleed the lines at the rear of the pump or do I need to bleed the lines at the injectors?

 

[JLandry]

Thanks for the response. I am in Davenport, Ia. I am working on getting wrenches right now so I can crack the lines to bleed the air. Is it enough to bleed the lines at the rear of the pump or do I need to bleed the lines at the injectors?

The correct procedure is to crack the #3, 4, and 5 injector lines at the cylinder head (not the pump) in order to push as much air out of the lines as possible. Crack the fitting a little, wrap a rag around each fitting to catch the diesel, crank the engine for 5 or 10 seconds (it may start), stop cranking, tighten fittings.



After tightening the lines and starting the engine, it may still run rough for a minute or two until all the air is purged from the injector lines.



Warning: Keep your fingers away from any loose injector lines when cranking or running the engine as the high pressure fuel being sprayed out can cut skin.



Best regards,



John L.

 

[wilcoxeng]

I am bearly getting fuel at 4 and 5 however I get fuel at all lines right after the pump. Is it possible that the FASS can push fuel all the way through the injection pump and the injection pump is not pumping? I assume that all I have to do to bleed the lines is to loosen the 19 mm nut at the head?

 

[JLandry]

I am bearly getting fuel at 4 and 5 however I get fuel at all lines right after the pump. Is it possible that the FASS can push fuel all the way through the injection pump and the injection pump is not pumping?

No... the lift pump shouldn't be able to push fuel through the VP44 injection pump unless something is terribly wrong internally with the VP44. If you're not getting a good flow of fuel out of the loosened fuel injection lines, then sadly, in all probability it's the VP44 injection pump that's failed.

I assume that all I have to do to bleed the lines is to loosen the 19 mm nut at the head?

That's correct.



I wish I had better news, but it doesn't sound good.



A rebuilt VP44 can be air shipped from any of the popular shops like Midwest Fuel Injection and installed by a competent mechanic in a few hours... or even yourself in 4 or 5 hours if you're mechanically inclined and have access to the proper tools.



Take care,



John L.

 

[wilcoxeng]

Thanks for your responses. In despiration I worked on bleeding the lines some more and was able to get good flow through 3, 4, and 5 at the same time and then the rest individually. Now I am back to the original problem where the truck idles but then stumbles terribly when the pedal is depressed. Should I be concentrating on the throttle position sensor? I am not sure if this situation qualifies as the "dead pedal" or not. Not sure what else it would be?

 

[JLandry]

Now I am back to the original problem where the truck idles but then stumbles terribly when the pedal is depressed. Should I be concentrating on the throttle position sensor?

Early on I thought about the APPS (Accelerator Pedal Position Sensor), but I don't see how it could make the engine stumble like you're experiencing. Typically if the APPS isn't working properly you'll either get a check engine light and diagnostic trouble codes, or sometimes the engine just won't accelerate at all (it just idles with no response from the accelerator pedal), or the engine will accelerate normally but seems to cut-out and/or briefly drop to idle in spots as the accelerator pedal is moved.



Lacking diagnostic equipment to rule more things out, it almost sounds like your VP44 has internal timing issues.



There's a Cummins service center right across the river in Rock Island, IL and I'll bet they have a VP44 tester which they can hook up and tell you in just a couple of minutes whether your fuel injection pump is the culprit or not. The tester is connected to the truck battery and also directly to the VP44 (after disconnecting the truck's wiring harness). The engine is then started with the tester running the VP44 completely bypassing anything on the truck. The tester causes the engine to run at a regular idle and also at a high idle. Assuming the engine starts and idles (like in your case), but the VP44 fails to respond properly to the high idle command, then you know it's bad and needs to be replaced. Simple as that.



Here's the contact info for Cummins:

CUMMINS CENTRAL POWER, LLC

7820 42ND STREET WEST

ROCK ISLAND, IL 61204



Phone: (309) 787-4300

Fax: (309) 787-4397



Operating Hours



EMERGENCY

24:00 - 07:00 MONDAY

24:00 - 07:00 TUESDAY

24:00 - 07:00 WEDNESDAY

24:00 - 07:00 THURSDAY

24:00 - 07:00 FRIDAY

00:00 - 24:00 SATURDAY

00:00 - 24:00 SUNDAY



PARTS

07:00 - 24:00 MONDAY

07:00 - 24:00 TUESDAY

07:00 - 24:00 WEDNESDAY

07:00 - 24:00 THURSDAY

07:00 - 24:00 FRIDAY

08:00 - 12:00 SATURDAY



SERVICE

07:00 - 24:00 MONDAY

07:00 - 24:00 TUESDAY

07:00 - 24:00 WEDNESDAY

07:00 - 24:00 THURSDAY

07:00 - 24:00 FRIDAY​

Rather than have your truck towed, they might even have a mobile repair truck which can come out to your location. But if the VP44 is bad, it's likely they'd want the truck in their shop anyway.



Best regards,



John L.

 

[JLandry]

One more suggestion...



Have you tried removing the EDGE programmer?



John L.

 

[wilcoxeng]

Ok, got a different reader this morning, and I am getting 2 different error codes. One is P1688 and the other is P0237. Any ideas on these codes?

 

[p-Bar]

P1688 is Internal Fuel Injection Pump Controller Failure

P0237Turbocharger Boost Sensor A Circuit Low

Got these off the internet, hope this helps

 

[JLandry]

Ok, got a different reader this morning, and I am getting 2 different error codes. One is P1688 and the other is P0237. Any ideas on these codes?

That P1688 pretty much tells you your VP44's computer has failed. The P0237 is likely nothing to worry about and occured only because of the engine stumbling.



Unfortunately, you need a new VP44 fuel injection pump!



Good luck,



John L.

 

[wilcoxeng]

Thanks for all the help and quick responses. Nobody had a pump in town so I ordered a new pump (Blue Chip Special X, I figured it would pay for its self in 50,000 miles) and rented a car to get home. The pump should be delivered tomorrow so I can put it in Saturday and get back on the road. 12 hrs at a rest stop and one day trying to figure it out. Should be one the downhill side now! Thanks again for the help.