Question about a fuel pump slipping a tooth?

[dieselcruiserhead]

Just wondering if its possible my injection pump skipped a tooth. Some months back it rattled loose in the middle of a 12 hour road trip and did it probably two or three times on the way home because I could only reach one nut with the tools I had at the time. Truck seems to run great but when first start misfires and I "seem" to recall times when I could get a lot more power out of it which I am not able to now. Top end is pretty good and honestly it does pretty well. Wondering if its possible I skipped a tooth, I also have some stumbling when the truck is super cold, for about 20 seconds but then its fine, no misfiring or stumbling. I assume this is normal but read somewhere that if it misfires when cold that it might have a skipped tooth. Or is it possible the pumps's cold start system maybe is malfunctioning or something like that? I don't notice any issues, justa big cloud of smoke when I fire it up...

 

[bgilbert]

I'd say no. Even if your mounting nuts came loose on the timing cover the pump gear is 'pressed' onto the pump shaft. So I don't think it would go anywhere. You just might have automatic timing adjustments from the pump vibrating one way or the other within the pumps mounting slots. BTW all sounds normal.

 

[dieselcruiserhead]

what is weird is that I don't have the power I used to though, even with the pump turned way up. Also I did, this latest round, have the engine putting out some decent power (still not a ton or as much as I've had in the past) but then I turned it down and then back up and can't repeat the power, it's almost non-responsive...



My pump has not been very easy to adjust powerwise at all when I am thinking I should be able to easily get over 200 hp especially with the setup I have but I guess not... Maybe time to take it to the dyno and do some real world adjustments for power and smoke... Anyone recommend a good salt lake city area dyno that isn't super expensive? thanks, Andre

 

[dieselcruiserhead]

Also you think it might be my lift pump? It is a carter/parts plus aftermarket for a 6BT model. I do have it sucking through a racor filter though but the filter is high flow... And unfortunately necessary... I can alway pump another pump (electric) into the setup I suppose?

 

[Greenleaf]

The hi-flow banjo bolts make testing the lift pump a snap as well as testing for fuel line/tank restriction.



Get a set of the 1/8th inch tapped variety and perform some troubleshooting with gauges. Best performed while the truck is on the road and loaded, such as floorboarding the thing up a hill. Temparary installed gauges will do.



-S

 

[dieselcruiserhead]

is there a spec that the pump should be at, a certain PSI? or something? I was thinking I would t the line and see what PSI it's putting out. . Or a volume gauge? I will start searching, I'm sure it's here somewhere...

 

[mechanic]

is there a spec that the pump should be at, a certain PSI? or something? I was thinking I would t the line and see what PSI it's putting out. . Or a volume gauge? I will start searching, I'm sure it's here somewhere...

This related to your first question.

Did you reset the timing after you got home? If not it could well be slow, and that will cause low power, smoke, rough running when cold, and more fuel consmption.

Also, you could have a damaged shaft seal because of the pump running in a loose condition, but that would usually cause a hard cold start situation. The VE type pump is not a tough as the P7100 is and will not get even close to the power output. The VE is limited because it is a single plunger pump with a 6 cam cam plate in it to fire/inject all 6 cylinders. At 2500 rpm the plunger is stroking 7500 times a minute. Put another way that is 125 strokes a second. If you try to go to a higher capacity plunger and cam plate, they tend to break the cam plate, and that is not pretty. That said, the VE is a remarkable little pump in stock condition and will give a lot of miles without problems.

 

[bgilbert]

:Yawn:. .



4BT man, the spec is 5-7psi after filter for a healthy lift pump. Minimum 3psi under load. Sounds more like the fuel pin that rides on the eccentric cone or pin is sticking on you at times. Thus giving low power or not as much power as in the past. Seems like you discussed this before. Greenleaf can fill ya in on troubleshooting a sticky pin.

 

[Greenleaf]

"Greenleaf can fill you in... ... ... "



Why is it always me... . LOL :-laf I'm going to change my name.



GL

 

[dieselcruiserhead]

:Yawn:. .



4BT man, the spec is 5-7psi after filter for a healthy lift pump. Minimum 3psi under load. Sounds more like the fuel pin that rides on the eccentric cone or pin is sticking on you at times. Thus giving low power or not as much power as in the past. Seems like you discussed this before. Greenleaf can fill ya in on troubleshooting a sticky pin.

hey ***... I wouldn't be so quick to diagnose the problem because I am not able to get the power off idle that I used to have before, even with stock injectors. Therefore I highly doubt it is a stuck pin issue. I will read through and see if there are directions on seeing what I can do about an unstuck pin but it is well lubed and appears to be working well... I have also not replaced my current AFC boost controller hose with something more rigid, yet...



The only reason I think it might be my lift pump is because this is the only real thing that has changed from then until now. I used to use an electric lift pump with a small inline racor under pressure. I now use the mechanical lift pump with a big-*** racor under vaccuum... The problem with the electric lift pump was it cycled fuel through the pump too quickly and would cut out around corners, etc, when less than a 1/2 tank of fuel...



There was a time when, even with my dinky little stock H1C, the engine was so loud and powerful off idle that it sounded like the loudest most cranked up 24 valve you have heard and the truck was a rocketship, I recall getting pulled over going up a one of the 20 mile grades at 83 mph with a lot more power and room to go and the engine was a just torque monster... Today I can't even keep it in 5th, even with tons of fuel dumping it seems. The power was throughout the whole curve, with very little smoke at the time, including even at idle... The only reason I turned it down was for noise and because the mileage was poorer... Since then, I have not been able to mimic this power with the same settings. I have reasonable EGTs and decent power but am smoking like crazy, especially when cold... I also occationally use this truck for some of the biodiesel coop's events as a promotional truck for "clean renewable biodiesel" so in theory it is important that it isn't smoking like crazy, which it is now...



GL, I did reset the pump timing slightly advanced but did not use any tools. I advanced mostly because of what is said here but assumed because it didn't slip a tooth or anything that I wouldn't need to reset back to normal before advancing. I am probably about 1/4 in clockwise advanced as the pump sits, but not all the way...



Also this problem has been for a long time and before the pump rattled loose so I don't think its timing related either... It started when I started using ether to get the truck to start on really cold mornings (less than 15*F). I started gradually losing power and getting higher EGTs and slight loss of coolant (though its possible I was leaking some as well) and determined I had a blown head gasket (for months actually). So I replaced it and the truck is actually doing very well now but there appears to be some sort of power loss isssue somewhere that I can't/havn't been able diagnose yet...



So that is basically what is going on so far...

 

[dieselcruiserhead]

Mechanic, also FWIW it was quite cold this morning and the truck started right up. I also have no glow or preheat mechanisms so I don't think its the shaft seal from what you mentioned. Honestly I am considering just yanking the injection pump and taking it in because I think the problem is there somewhere. Because it seems to run "pretty well" I am sure I can get something for it at the injection shop. But I don't have the money to do this and would rather correctly diagnose the problem...



Also the big reason I am asking you guys is there is very difference between the 4BTs and the gen 1 6BT's, same pump, injectors, turbo etc. In theory everything else should be the same...

 

[bgilbert]

Ah ha biodiesel, there in lies your problem. Good ole #2 works for me :-laf Oo. . There's your ahole comment. I missed the part where I was in my last comment. I was just giving specs.



Changed your fuel filter lately? Check your fuel pressure. Get yourself a tapped banjo from www.genosgarage.com, a boost tubing kit and you can use an old boost gauge 0-30psi or any pressure gauge as long as you can read it at 0-5psi to check fuel pressure.



Btw, with it not having cold weather emission items (grid heater, ksb timing advance solenoid) you're gonna get smoke during cold weather until the engine is at operating temp, more so I bet with your biodiesel.



Edit: Alan is right, I somehow forgot to include mechanic's quote...

 

[Paychk]

hey ahole...

Do you think that disguising & using profanity is really going to help with the problem you are experiencing?



I think you may have misunderstood the "yawn" comment of Bgilbert's that was directed at the, "The VE type pump is not a tough as the P7100 is and will not get even close to the power output. " comment of mechanic.



There is a certain level of decorum that we 1st. genners use and that comment is really way over the line.



dieselcruiserhead you may owe an apology after things calm down, and you think things over.

 

[JLEONARD]

Hey let's play nice again...



I've read that biodiesel can clog up the filter initially after the first few tanks full... . have you checked the filter lately? (you probably did and I may have missed you saying that)

Also regarding your Racor vacuum type set up... thousands of that set up in marine applications and they don't have problems..... normally. My experiance with a clogged filter in that type of set up is that the high power will drop off and mid range power will be fine. What size (micron) element are you using?

Are you absolutely positive that the top of the Racor is sealing properly? Might be worth removing the cover, wiping the o ring and re-installing... I've seen this many times in the marine world, on mine and others.

Hope this helps.

Jay

 

[dieselcruiserhead]

I do owe him an appology because I was slightly out of line but also because he was right... Bgilbert sorry and I do appreciate your input on this and the last thread about this as well and you have been nothing but helpful. I did not like being addressed as "4BT man" because I am not some idiot or an amateur mechanic and I don't like being talked to like I'm sort idiot, because of my post count or because I am not a Bosch VE pump expert.



... In fact the pin is sticking... I ran without the diaghram/pin in and the pin will not slide out... It also appears to possibly have been an issue for a PO because there is definetely some wear/markings on the allen nut that appears to house the pin mechanism... What adds pressure to the backside of the pin to push it out? - a spring, fuel?



The only reason I have been able to get reasonable power out of is because I have the full power screw almost all the way in. I have been able to get the pin to come out somewhat (and can feel it under the pedal) usually after several miles of highway driving.



FWIW all the filters were actually changed just yesterday and I am currently running 100% dino diesel. But for what its worth the rig seems to run much better on biodiesel blends, it is a killer lubrication additive (2 % bio = same lubrication of high sulfur fuel, so imagine 20%), and it is pretty neat to be able to brew your own diesel fuel, that comes from farmers, that is $. 80 a gallon...



paycheck, TDR is what disguises the 'profanity' not me...

Thank you guys though, I really do appreciate it all...

 

[dieselcruiserhead]

Leonard the racor definetely is not leaking, the big thing is I would be getting air in my system if it were and I definetely am not. I figure the lift pump should be fine with the Racor but you never know.



A neat thing about the Racor (325 series) is I have some idiot lights that came with it that tell me when there's water in the seperator and when to change the element. It also has a built in heater as well... I figured the lift pump could handle it because its mechanical and generally mechanical pumps have no long term problems "sucking" or with a load on the vaccuum side, unlike most electric pumps, but you never know and I am just starting to learn in depth about Cummins engines...



Here is also the fuel system I run, I run dual pumps with an electric that keeps this tank full all the time so I have fuel at extreme angles. I also run a cheapo inline Fram filter before this mini tank and that seems to catch 90% of the junk from even biodiesel and makes the expensive factory & racor filters last a lot longer...

Hey let's play nice again...



I've read that biodiesel can clog up the filter initially after the first few tanks full... . have you checked the filter lately? (you probably did and I may have missed you saying that)

Also regarding your Racor vacuum type set up... thousands of that set up in marine applications and they don't have problems..... normally. My experiance with a clogged filter in that type of set up is that the high power will drop off and mid range power will be fine. What size (micron) element are you using?

Are you absolutely positive that the top of the Racor is sealing properly? Might be worth removing the cover, wiping the o ring and re-installing... I've seen this many times in the marine world, on mine and others.

Hope this helps.

Jay

 

[Paychk]

dieselcruiserhead No problem!



here is a diagram that may help in freeing the fuel pin:



#ad

 

[dieselcruiserhead]

and thank you paychk...

I really do wonder what pushes that pin out... (#5 above) Honestly my best guess is that its fuel pressure which is why it gets stuck so easily, versus a pin. I also can't see any springs on the back side of it. So I'm wondering if I am able to remove that backside but (on the throttle side) if I can stick something in there to push it out and clean up...



Thanks for the diagram...

 

[mechanic]

Do you think that disguising & using profanity is really going to help with the problem you are experiencing?



I think you may have misunderstood the "yawn" comment of Bgilbert's that was directed at the, "The VE type pump is not a tough as the P7100 is and will not get even close to the power output. " comment of mechanic.



There is a certain level of decorum that we 1st. genners use and that comment is really way over the line.



dieselcruiserhead you may owe an apology after things calm down, and you think things over.

Sorry to offend you guys. But with 25 years of expience on diesels and most of it on VW's with the VE type pump and rebuilding some of them in part or in total. I wrongly thought that I might be able to help. The diesel shop that supplies me with parts is a Bosch authorized repair center. They have rebuilt thousands of pumps over the last 5 or 6 decades. I was passing on what I was told when I asked them what they could do for customer's truck (a 91 350 with a cabover box and pulls an 18' trailer with 8 to 10,000#) that would make more power. They didn't say and I didn't mean to imply that the VE will not make power, but he did say that the reliability goes down, and that they have had problems with the camplates breaking when they pushed they up very much.

Really though, if you know of a reliable way to get the fuel delivery up with a VE pump, you should tell the Bosch pump repair network about it and how to do it, because the two of them in this area do not know about it.

I will back out of this part of the forum and leave it with you guys. Again sorry for offending, I was tring to help.

 

[Paychk]

Sorry to offend you guys. But with 25 years of expience on diesels and most of it on VW's with the VE type pump and rebuilding some of them in part or in total. I wrongly thought that I might be able to help. The diesel shop that supplies me with parts is a Bosch authorized repair center. They have rebuilt thousands of pumps over the last 5 or 6 decades. I was passing on what I was told when I asked them what they could do for customer's truck (a 91 350 with a cabover box and pulls an 18' trailer with 8 to 10,000#) that would make more power. They didn't say and I didn't mean to imply that the VE will not make power, but he did say that the reliability goes down, and that they have had problems with the camplates breaking when they pushed they up very much.

Really though, if you know of a reliable way to get the fuel delivery up with a VE pump, you should tell the Bosch pump repair network about it and how to do it, because the two of them in this area do not know about it.

I will back out of this part of the forum and leave it with you guys. Again sorry for offending, I was tring to help.

You may want to read this :



https://www.turbodieselregister.com/forums/showthread.php?t=141923



I don't think you really offended anyone, it just gets old hearing about the VE pump and it's lack of potential. Everyone here would most likely agree that the VE won't keep up with the P7100, but that doesn't mean it can't make reliable big power.



As far as the Bosch repair centers they don't care & will very likely do what ever they can to discourage this type of development. Why? because the Bosch cert. is at stake and they won't take a chance on destroying their livelihood over a couple tuners doing backyard tweaks. The cost benefit analysis doesn't make it worth their while.