Losing prime

[Mark P]

Yep… kinda leaning in that direction myself. I’ve talked to several that made the switch to VE pump and used the injectors for the VP, with no issues, but that doesn’t mean they will all work like that. I’ll try to call the shop tomorrow and see what they think. THANKS!!

 

[Ozymandias]

Yep… kinda leaning in that direction myself. I’ve talked to several that made the switch to VE pump and used the injectors for the VP, with no issues, but that doesn’t mean they will all work like that. I’ll try to call the shop tomorrow and see what they think. THANKS!!

Just did some reading and it is a can of worms... everybody has a different opinion about what pop pressure is appropriate for a 24V with a VE pump, which it wasn't designed for.

 

[Mark P]

Just did some reading and it is a can of worms... everybody has a different opinion about what pop pressure is appropriate for a 24V with a VE pump, which it wasn't designed for.

I was just reading on it as well. It seems that high pop pressure (24v) on a ve pump actually retards the timing, since it takes longer to get the desired pressure. It makes sense now. Could be the reason it’s starting hard. The KSB helps, but can’t advance enough to make up the difference of the retard from high pop pressure.

 

[Ozymandias]

And with lowered pop, matching the VE pump, it smokes.

 

[Mark P]

Yea.... I'm not a big fan of a trail of black smoke behind my truck. Living in WV, we have 80% hills and 20% level ground. It only gets worse on a pull. I sure don't wan to wear out a new pump prematurely with too high pop pressure.

 

[Mark P]

I'm not having any luck at finding a shop local to set pop pressure. I've used a local shop to rebuild a few pumps before, but they didn't really want to set pressure on injectors with unknown mileage. They said I could drop them off, and they'd take them apart and inspect them, and then let me know if they were willing to do it, but they prefer that I buy a new set to start with. Has anyone here set the pop pressure themselves? I normally buy any tool that I might need, and the tools to check the pressure are only a couple hundred dollars. Is it worthwhile??

 

[petersonj]

Diesel Auto Power does a lot of custom injector work. I think it would be worth a call to talk to them about your situation.

- John

 

[Ozymandias]

It's not so easy to set the pressure correct with this basic cheap pop-off Tools.
How many miles on your injectors? Might be time to get new ones anyway.

 

[Mark P]

I’m not sure how many miles are on them. 370,000 on the truck and about 45,000 on the motor. I tried to get in touch with the previous owner, but haven’t gotten in touch with him yet.

 

[Ozymandias]

At 370 they sure would be ready for replacement...

 

[Mark P]

I really can’t believe these would have 370k. This truck runs too good to even think that, although a fresh set may be the way to go. I need my truck!!

 

[NIsaacs]

Any chance the pump was timed retarded and not advanced? I think I would try it timed where specs calls for. Did you use one of these VE timing tools?

https://r.search.yahoo.com/cbclk2/d...DMgRydAMw?IG=0acd6654e02442549d00000000a5fef0

 

[petersonj]

I really can’t believe these would have 370k. This truck runs too good to even think that

I could believe it. I changed my OEM injectors at 303,000 miles just because I thought it was time. They were performing fine - no smoke, quick starts, lots of power, and good fuel economy.

Any chance the pump was timed retarded and not advanced?

I thought about that, too. But, he said the truck drove well with lots of power, so I kind of discarded that thought.

- John

 

[Mark P]

Any chance the pump was timed retarded and not advanced? I think I would try it timed where specs calls for. Did you use one of these VE timing tools?

https://r.search.yahoo.com/cbclk2/dWU9RjdBRDA3QzQ3QjAxNDM4RSZ1dD0xNjk5NjYxMzI0MTA5JnVvPTgwMTk1NjgxMjA1NzcyMSZsdD0yJnM9MSZlcz0zTkczbE93R1BTX0ZOcGpTLllqZ2lLN19NSVRiM2NYeDZUN2M3NjZvbWRPcEd3dzg-/RV=2/RE=1702253324/RO=14/RU=https://www.bing.com/aclick?ld=e8j4fN6JQVX2v6Or0oTJRZKDVUCUxFPaPLgZzCLToYV6cFIy1OElLTVwXH86qIgjJX3RgCieJXy4MmfkuyD14FSbisjnmYRvyZslsKsGbwydI5F75j_vc4PVZJexnRVid4BUrFu4hIA3jKxR67SUubXuh4Z0VnmEA0iEREE87H2SOVSF0V8W0k92qK3FBL7DSbUQLH3g&u=aHR0cHMlM2ElMmYlMmZ3d3cuYW1hem9uLmNvbSUyZkVXSy1EaWVzZWwtSW5qZWN0aW9uLVRpbWluZy1JbmRpY2F0b3IlMmZkcCUyZkIwMEg5N0oxTVUlMmZyZWYlM2Rhc2NfZGZfQjAwSDk3SjFNVSUzZnRhZyUzZGJpbmdzaG9wcGluZ2EtMjAlMjZsaW5rQ29kZSUzZGRmMCUyNmh2YWRpZCUzZDgwMTk1NjgxMjA1NzcyJTI2aHZuZXR3JTNkbyUyNmh2cW10JTNkZSUyNmh2Ym10JTNkYmUlMjZodmRldiUzZGMlMjZodmxvY2ludCUzZCUyNmh2bG9jcGh5JTNkJTI2aHZ0YXJnaWQlM2RwbGEtNDU4Mzc5NTI2OTU1NDEzMyUyNnBzYyUzZDE&rlid=0b5a7a8f90ab1e99a1821fc156a74d23/RK=2/RS=chbMnDLG14dg9gQoZayS2eCFem0-;_ylt=AwrNZlQMxk5lndoMe1JXNyoA;_ylu=Y29sbwNiZjEEcG9zAy0yBHZ0aWQDBHNlYwNvdi10b3AtcGxh;_ylc=X3IDMgRydAMw?IG=0acd6654e02442549d00000000a5fef0

No chance at all. I used a grease pencil to highlight the timing marks, and set the pump gear on "C", instead of "E", which is a common. The VE pump uses a key on the tapered shaft to line it up. It can only go in the gear one way.

 

[Mark P]

I plugged the truck in last night, and we had 41 degrees in the night. This morning it started with one or two turns of the engine, and had almost no white smoke from the tailpipe. BUT.... without plugging it in, even on a 74 degree day, it takes a lot of cranking to get it to fire up, and you can't see the truck for the white smoke.

 

[Ozymandias]

Bad compression? Weak starter?

 

[NIsaacs]

No chance at all. I used a grease pencil to highlight the timing marks, and set the pump gear on "C", instead of "E", which is a common. The VE pump uses a key on the tapered shaft to line it up. It can only go in the gear one way.

I guess I am not familiar with "c" or "e". Are those letters on the cam gear or the pump gear? I am also not familiar with a VE on a VP engine, so I am kinda lost.

On a VE engine and a VE pump, if the engine is locked on TDC and the pump is locked on TDC, the key is automatically lined up and all you have for timing adjustment is the pump mounting bolt slots.

White smoke indicates retarded timing. It runs fine because of the KSB and the VE pump has mechanical advance and maybe overcomes the retarded "start" timing?

Where is the pump in relation to the adjustment slots, full advance, full retard or somewhere in the middle? Have you changed that setting at all in your "start" trouble shooting?

 

[Mark P]

I guess I am not familiar with "c" or "e". Are those letters on the cam gear or the pump gear? I am also not familiar with a VE on a VP engine, so I am kinda lost.

On a VE engine and a VE pump, if the engine is locked on TDC and the pump is locked on TDC, the key is automatically lined up and all you have for timing adjustment is the pump mounting bolt slots.

White smoke indicates retarded timing. It runs fine because of the KSB and the VE pump has mechanical advance and maybe overcomes the retarded "start" timing?

Where is the pump in relation to the adjustment slots, full advance, full retard or somewhere in the middle? Have you changed that setting at all in your "start" trouble shooting?[/QUO

This is a bit long, but bear with me.............

Before I set the timing on the pump gear, I wanted to find out the difference between the E and the C stamped on the pump gear. These are the only 2 letters I have ever heard mentioned in the timing of the VE pump. The crank has a single O on it, and it goes between two Os on the cam gear. This was marked with paint on the crank, cam, and pump gear by someone else, prior to me starting the swap. Also, I took pictures of each step of the process, including the timing marks. Easy enough, but the single O on the cam gear goes where on the VE pump gear?? The pump gear has several letters on it.... G,D,E, and C, on the side that I needed to time from, and F, B, H, and A, on the side that is about 180 degrees out. From what I read, the 12 valve would typically time with the single O on the cam gear, to the E on the pump gear. The C was used more for use on industrial or power plant engines. It gave a 10 degree advance, which would normally give a bit more power. The guys running the 12 valve pulling trucks with a VE pump, which I know several, are running 2 teeth advance with no issues, but.......... they aren't running 24 valve injectors.

With the issues I've had this past week, I thought it was losing it's prime, but Big Papa hit on something I hadn't thought about. POP PRESSURE I know guys that have installed the VE on 24 valve and run the original injectors with no problem. Older injectors can lose a small amount of pop pressure of the years. Maybe that's how they are getting by with it?? My engine has about 45,000 miles on it, but I have no idea the age of the injectors. I've been reading up on pop pressure and the effects it can have with higher or lower pressure. The injectors used for a VE pump have a pop pressure of 248 bar (3550 psi) and the injectors for a 24 valve are set to 305 bar (4500 psi), As I understand it, as the VE pump "struggles" to produce enough pressure to open the 24 valve injectors, the engine has passed the exact time for the fuel, and gives the appearance of a retarded time. It would actually be more of a duration issue, but the injector is firing off late, causing the hard start and white smoke. As for the KSB, on my last truck, a F350 with a 1990 12 valve, I didn't even hook the KSB up. It started/ran fine winter and summer. On this truck, when it's running perfectly and I unplug the KSB, it almost quits. Now......... why does it start easily plugged in? Maybe with the heat, it's thinning the fuel enough that it pumps a bit easier?? No definite answer there.....

As for the "locked" position of the pump, they don't need to be locked since they have a keyway. You set the pump gear/cam gear relation, and turn the pump until the keyways line up. The pump is set to the retarded position, and I haven't tried to adjust it more to advance. I may try that today. The reason I haven't, is that a VE on a 24 valve is a bit tighter than a VE on a 12 valve. Instead of having 6 1/2 degrees of total movement on the slots of the pump, there is only about 3 degrees movement max, because the pump hits the head. I should have ground a relief in the intake part of the head before I installed the pump. If I have a reason to remove the pump, I'll do some grinding. This is my first (and last) 24 valve/VE combination.

The pop pressure seems to be the most logical explanation so far. Even as good as the truck runs once it starts, I'm hesitant to drive it much with the risk of damaging a new VE pump. I think that a new set of injectors with the correct pop pressure may be the best thing. Find out soon. THANKS!!!

 

[BigPapa]

@Mark P , your reply is inside the quote. Edit it and cut the “[\quote]” at the end and put it in front of your reply.

 

[Mark P]

@Mark P , your reply is inside the quote. Edit it and cut the “[\quote]” at the end and put it in front of your reply.

Thanks... I hadn't even noticed that. I think I got it now...