Think my Injector Pump is shot

[tbearatkin]

I will start looking for an air leak. It starts great in the morning. Just no power. GP light comes I depress the pedal half way light goes out 10-15 seconds later turn the key to engage the starter and it fires off.

 

[tbearatkin]

I have not been able to find any sign of air leak. No fuel around any of the injectors so no apparent leak there. Traced my lines along the frame back to the tank and did not see any area where air might be sucking in. Took off my air filter and reattached it just to make sure I had a good seal. Re bled the system of air. Clean diesel no off color bled into my container.


I went to start it. Glow plug light (check), depress pedal halfway (check). LIght out and turned key to start. Started right up. idled fine. GP relay cycled a couple times. Took it around the block for a drive. Low power still.

I got it back home let it sit running a couple minutes. Then depressed the pedal all the way to the floor. Nothing at all then a slow build up of RPM's to high RPMS but there is white smoke out of both exhaust (not antifreeze). Let up on pedal and returns to idle and no white smoke. Cannot reive the engine just the slow buildup of RPM's if I hold the pedal to the floor until it has full RPM's with white smoke.

Will keep checking on airleak (might have to go with a round fuel filter housing swap), but do bad injectors have this symptom? While it says 60K miles it might be 160K.

 

[tstone]

I really believe that your issue is a weak IP, your symptoms are identical to what happened when my pump started to fail. If you want to confirm this you can turn up the IP fuel injection volume (1/3 to1/2 turn) until it is convenient to install another one. I could try to describe the procedure to you but it would be easier if you could locate the thread that describes the procedure with pictures. Ive been running my turned up pump for about 2 years as Ive been too busy to change out my old pump but I need to do it before it permanently fails. Hope this helps.

Tom

 

[NCBloodhound]

Any updates on this? I am now having a very similar problem. My CUCV doesn't stall, but has NO power uphill and randomly while driving.

 

[tbearatkin]

No update to a solution at this time. Mechanic at a Military rebuild center near here says it sounds more like the fuel pump. Life is getting in the way of me replacing that and the lines going to it to see if this solves the issue. At least that is a cheaper trial and error item to replace instead of the IP. But will post an update what the outcome is when I replace it.

 

[appalacious]

seems like the advice hasn't been to replace the IP, but to turn up the fuel...why not try that? Your LP test was good you said...

 

[Bob USNR]

If I remember correctly that is the Roosa-master/Stanadyne injection pump. They are prone to several types of internal failures.
One of the most common is a plastic ring attached to the fly weights in the governor assy. It serves as a shock absorber. Typically tiny pieces of it get stuck in the glass ball of fuel outlet connection. Causing low pressure in the injection pump.
These are not "user serviceable" items. They are rebuild issues.

I don't use just "volume over time" tests to check fuel supply to the pump. I also test pressure at the same time.
I want 10 psi at >tested at the pump inlet fitting< while driving at full throttle.
e

 

[AceHigh]

Just came in from replacing mine. Its symptom was started great, ran great but would not start if you tried to start it up to 2 hours after shutdown.

 

[MakersTeleMark]

Just came in from replacing mine. Its symptom was started great, ran great but would not start if you tried to start it up to 2 hours after shutdown.

Care to post your process? I'm in the same boat and am heading down that path.

Thanks.

 

[keefer]

replaced the injection pump. no joy. it still shuts down after a few minuets of driving. i have replaced everything in the fuel system so far. i replaced the filter sock, fuel filter, all rubber lines, fuel pump and the fuel. im at a loss for words.

 

[MakersTeleMark]

Clogged injectors?

 

[Bob USNR]

replaced the injection pump. no joy. it still shuts down after a few minuets of driving. i have replaced everything in the fuel system so far. i replaced the filter sock, fuel filter, all rubber lines, fuel pump and the fuel. im at a loss for words.

When I had a similar problem it was loss of fuel pressure to the IP.
You must test the pressure at the pump. I would not be happy with pressure below 3 psi. I like at least 5 psi. If pressure is adequate, at the pump, the rest of the fuel system, upstream, is working correctly.

e

 

[tbearatkin]

Okay the cause of the issue was the Injector Pump. Oh well I have a spare mech fuel pump now and the knowledge on how to change it out. Also the vacuum lines were hooked up that way because the vacuum regulator (PN 14057219) was bad so that was replaced as well.

Injector Pump 1 yr warranty- $325
Gasket and installation kit-$27.95
Vacuum Regulator-$100
Labor- $80 hr 6.25hr=$500
Government cut of the pie- $78.90
Total 1031.85

Runs like a champ now.

 

[tbearatkin]

and the final addition is $80 for new glowplugs.

I had disconnected my glowplugs while I was changing it all out to keep battery discharge down while bleeding air out of the system and with the horror stories I had read on here about mechanics blowing engines up because they used Starting fluid I decided to leave it disabled when I sent it to the shop. I did show the guy I dropped it of with how I had it disconneted. All he had to do was hook it back up to the 12volt battery. Well he must not have passed that on to the mechanic who worked on it. When I went to pick it up the mechanic said it was hard to start but ran great when started and he could not figure out how I had the GP system wired. I showed him but I have a sneaking suspicion that he hooked it up to the 24 volt side of the system. I know the GP were all good when I took it in because that was one of the things I checked when it still would not start after replacing the the mechanical fuel pump. But can not prove they did anything as the wire was just like I left it, disconnected when I picked it up. It was warm so started right up. Next morning nothing so checked the plugs and all were bad. Had a spare set replaced them and checked the relay to make sure it was not damaged by the 24 volts should not have been but you never know. All works as it should now.

Guess I would not have had this issue if I had used the firewall connection instead of the battery connection

 

[mr.travo]

I am glad you got it figured out and fixed! Sorry about the price and frustration. I DREAD the day I have to replace my IP. I can foresee a pair of hurting knees and cut knuckles! LOL!

 

[tbearatkin]

Glad it is working as well. Drive it now a few times a week and on the weekends all the time.

 

[usmcpatriot]

Consider a dirty fuel sender, had the same problems. Dropped the tank, fuel sender sock clogged. Washed out tank, replaced sending unit. Problem solved.

 

[keefer]

ya i tried that. i went through everything. replaced all the lines, filters, injector pump, fuel pump. nothing works