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VE pump timing?

1173 Views 30 Replies 4 Participants Last post by  Blackduck596
OK, I know there is alot of info I've read on this forum on this but need to pick a little deeper.
Found this old thread CPL VE timing specs with great info on CPL# and settings for plunger but still a little concerned about my setting.

I have a 1985 engine 94hp @ 2200rpm with CPL 592 and timing on data plate stating 2.0mm plunger timing which also lines up with the other data I found in the link above. Had the local 'tuner' work on it and apparently 'timed' the pump but bumped it a bit.... from what it was when I bought it(? unknown), to what he bumped it to was questionable until I measured with dial gauge. Was measuring at 1.7mm on the dial gauge that he'd bumped up to.
Seemed to run a more smokey (especially on start up/cold) with EGT's climbing rapidly under acceleration compared to where it was at 'pre-tune'. See pics below of piston tops when I removed the head. Note; cleaned up there was no signs of melting spots which was a good thing.

Having pulled the engine out to re-seal oil leaks and re-do leaking head gasket(needed the new DCEC head decked to get true flatness) and also have it O ringed, I don't want to risk getting this wrong.
Back story on the engine if it helps, VE pump with 3200 spring and fuel pin, std rebuilt bosch injectors, 60lb valve spring, ported exhaust ports and port matched exhaust manifold, stage 2 colt cam and going to be running a new HX30 Super.

So, with all that said and done, my concern is that if the pistons looked like this when pump was set at 1.7mm, thinking it will be worse again pushing it up to 2.0mm as per data plate. Thoughts and advice??

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Steve, that would be my question too. In fact, that burn pattern on the pistons looks like 155 deg injector spray pattern on 145 deg piston bowls. Of course timing could also be causing that. Also, that strange burn pattern on the piston top looks like a poor firing injector. The fact of the smoke and rising EGT makes me think the boost isn't matched to the fuel. Too much fuel and not enough air makes heat and smoke but not power.
Thanks guys,
Injectors were rebuilt less than 3000km ago by a 'reputable' diesel turbo/injector business in Sydney. I also had the turbo(HX30w) rebuilt also but have since had massive issues with oil being fed into the intercooler and intake. was only running 18psi also. Mate told me to check shaft play and has what I would describe as 'excessive' side to side play at around 2mm either way. End play is fine.
So, with the turbo no good(hence upgrade to the HX30 Super) I suspect the injectors could well be rebuilt with 155 degree nozzles, NOT the same as I had originally. Unfortunately with a move of house I can't find the receipt.... I was told they would only rebuild as per standard... so believe they are a 5 x 0.12?? do I check if 145 or 155??

Recommendations on injectors?? Would rather buy new, knowing what I get rather than go through this again..

To be honest, everything that can go wrong with this thing has .... I struggle to trust businesses with doing work for me or on my cars for this exact reason. I just want the thing running and driving. :mad:
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The 5x.012 injector is a popular upgrade. Those tips came in both spray patterns. If the company rebuilt your originals and changed just the tips they should be the same pop pressure. VE pump require 245 bar pop pressure. P7100 pumps where those 5x.012 injectors were used use 260 bar. Wrong pop pressure would cause retarded timing, poor power, and hotter EGT. On your original turbo, did you check the shaft diameter for wear? If the shaft was within tolerance, then the issue was bad bearings. Either issue could be corrected by replacing the turbine shaft or just new bearings. Minimum shaft bearing journal diameter is 10.97mm. Also, the 18 PSI boost is bone stock on an HX30W. It can easily do 30 PSI or a bit more. You have to adjust the waste gate control to allow for more boost. Too much fuel and restricted boost also makes high EGT. The fact that your turbo went bad in such a short time would concern me as to whether it was properly rebuilt.
Unfortunately I don't have any local workshops where I live that can check/test injectors.
Can I disassemble them to get nozzle numbers and reassemble without issue? Or will it affect pop pressure etc?
Ok guys.... a bit more info to help and work this shit show out.
I pulled one of my injectors apart... as in just the end cap and nozzle so I could read the part number on it., retorqued to 55ft lb once done.
So what I found was... part number on nozzle reads like this;
DSLA 145 P 311 85332
Brasil 685
Pretty sure it's a 6 hole nozzle(my eye sight is failing me lately.)

The injector kit/ I bought had 3 thickness washers there for installing(0.5mm/1.5mm/2.5mm), so I just matched up what was originally on it with the previous injectors with the 1.5mm ones. But now looking at those photos above and the spray pattern in the top of the piston, Im wondering do I go down to the 0.5mm ones to have it inject into the bowl more??

Side note, previous injectors were;
12v 5x .014 145 606 3.20

Still concerned about the VE pump timing at 2.0mm and gut feel it it's too far advanced. Would the stage 2 colt cam be different profiles than the standard one for my engine that would warrant concern of timing advance?

Aside from this.... the only other thing I can check is to pull the front timing cover off to check cam gear hasnt been bumped a tooth.(pretty sure it hasn't from memory when installing the cam. I did take a photo of meshing marking but daughter deleted the bloody thing.)
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Righto, so I bought a pop pressure tester. Found same unit here in Oz that Steve posted up before but unfortunately was $185AUD :rolleyes: BUT..... after testing all injectors it did highlight a small issue.
I can't recall which injector was in which cylinder but pop pressure readings were as below. My pop tester unit measured in PSI, so had to convert to BAR.(Injectors are in no order just as I tested off the bench)
INJ 1 - 3550psi = 244.8 bar
INJ2 - 3300psi = 227.5 bar
INJ 3 - 3400psi = 234.4 bar
INJ 4 - 3450PSI = 237.9 bar

How much of a problem is this variation in pop? Would this have caused the issues seen on the top of the pistons?
Plus side is..... spray pattern looks really good with no leakage.
Issue now is to get this rectified somehow. Hoping possibly a diesel shop an hour away I might have to get to to set these correctly.
If you wish to have a go yourself I have bought shims in Aus but not from Bosch.
Rough ball park to start is 2 Bar per .01 mm of shim thickness.
Thanks mate. Where exactly would I start looking for these shims? Online(what to search for?) or diesel shops?
Google Precision Shims. In Victoria. I have sent you a PM.
I used the 3.1 ID x 6.8 ODx .6 and the rest are 3.% IDx6.8OD x (1.30 to 1.75)
Need to measure the current shims and see what you can shuffle around and work out what you need to order. Don't mix up any of the rest of the injector parts. Don't use anything abrashive on any of the mating surfaces. Check the springs are free in the bodies, if the holddown nuts were tight and the injectors turned a little the locating ball can distort the bore in the injector body causing the spring to bind. Have found it is better to go to about 247-249 BAR when setting up as they seem to settle a little very quick.
Cheers Steve
Thanks mate. How many shims did you need? How many would you recommend me buying?
You need to find out what you have currently then using a rough guess of 2 BAR for .01mm of shim thickness you can roughly work out the changes needed to the current shim pack. All I have pulled apart had 2 shims in them and around 2mm total. A case of measure each pack then each shim and see what you can shuffle around and what you would need to make a new pack using either all new or some old and new. Allowing for some extra if needed.
Cheers Steve
Righto Steve.... shims arrived from Precision Shims. Ordered the same as you've used 3.1 ID x 6.8 ODx .6
Last few questions for now;
** when disassembling the whole injector body internals is there anything that is likely to 'spring' out/away when pulling apart the internals of the injector or things I need to be wary of?
** reassembling the injector, do I put any lube on the thread on the body of the injector when needing to retorque to 55ft/lb?
Basically, anything else I should need to know or be concerned about before I crack into this tomorrow arv?
Ok guys... so Im moving along with this. After injectors were pop tested as below results, I disassembled each to find one had a shim in it and the other 3 had none.
INJ 1 - 3550psi = 244.8 bar - Nil shims
INJ2 - 3300psi = 227.5 bar - Nil shims
INJ 3 - 3400psi = 234.4 bar - Nil shims
INJ 4 - 3450PSI = 237.9 bar - 1.8mm shim

I bought the same shims as Steve used (3.1 ID x 6.8 OD x .6) and tried 1 shim in each of the injectors with lower pressure and reassembled(shim placed ontop of the spring between spring and main injector body, to 55ftlb however could not get it to pop/spray with a shim in. Disassembled and removed shim, reassembled and ended up having all 3 injectors re pop test between 244-248 bar. I can't work that out... but anyways will leave them for now and re test again in a few days.

Onto the next thing I'd like to confirm.... VE pump gear markings/timing. Trying to rule out everything I can... I pulled the front cover to check the IP gear is correctly located. Found the Cummins bulletin 3379133-20 which states '0' on cam gear marries to 'B' on IP gear... so... I assume my pump is at standard and not bumped(good!!)

Now, with this said and done, my main concern now is.... given the injector spray pattern marks on top of the pistons previously and pump timing was 1.7mm on dial gauge.... Not sure I should be advancing it to 2.0mm as per data plate without causing more issues.
I want to get the dial gauge on the back of the pump and get this right so I'm not worrying to drive it once it goes back in this weekend(hopefully)


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If you get them all within a 5 bar zone that is pretty good. The engine will run better the closer you match them. Since your injectors have been used the internal spring has relaxed some. Not uncommon. After you get them back to specs they won't change much. Those little shims come in 30 different thicknesses so you could spend hours getting them right on the 245 bar mark. Your #1 was dead on the mark. #2 was pretty bad off the mark. The other 2 were sort of in the middle.
Thanks mate. Im still stumped how the shim I put in would not allow it to pop/spray at all then when I disassembled and removed, reassembled back to the way they were originally and retested they were pretty much at spec. (??)

What about the pump timing and concerns with that given the markings on top of the pistons?
No shims certianly makes it hard to set without a lot of messing around.
The 1.8 would most likely come up fine with 2.0 in it.
Char may have handle on the thinest sizes Cummins supply but Precision do not have thin shims.
Are you 100% sure there were no shims stuck in the bodies?
Thanks Steve. I'm sure there were no shims in those other 3 which I found quite odd given the other had a 1.8mm shim.
I'm tempted to pull them apart again.
Still got me stumped why it wouldn't pop/spray with one single shim added the same size as you used. Just didnt make sense.

The other thing.... should I be concerned with the 2.0mm timing on the pump given the spray pattern on top of the pistons at the start of the thread? Can't afford for this to go wrong anymore or risk damage.
Ok guys, rig is up and running.... finally, YAY!!
Have timed the pump at 2.0mm as per data plate BUT.... even with the new HX30 Super on seems to be running extremely lean. Tiny puff of smoke at take off but other than that... nothing, no smoke even with WOT for the short bursts I could around town. EGT don't go over 300 degree celcius(570f)
Checked power screw and from bottomed out, was turned out one turn and locked off.
Smoke screw is all the way out.
Star wheel was level with top, basically all the way out. I screwed in 3 turns and didn't see much change... maybe just a little more poke but not worth stating it made a difference.
Does not have the standard mechanical lift pump, different setup in the conversion I have so, .... it HAS an elec lift pump which I don't believe is delivering anything over about 2-3psi post filter before IP(it is a new filter). Shitty fuel pressure gauge I put in didn't even move before I started engine(should show some movement as is should be priming with engine not running). So in saying this, will be looking to replace with another elec lift pump. (What psi/volume elec pump should I be aiming for?) Budget cant do FASS, but was looking at a Carter or Holley

I don't have any tuners nearby(nearest reputable cummins one is about 5hrs away) to look at the truck so I'm trying to tune myself so I melt a piston of the like.
Was thinking of adjusting back to 1.8mm timing and see what difference this makes. Thoughts?

To go back over the truck setup....
  • CPL 592 with VE pump
  • Timed to mark 'B' in IP gear
  • ARP head studs
  • 60lb valve springs
  • O' ringed head(new head)
  • Stage 2 colt cam
  • 3200rpm spring and fuel pin
  • HX30 Super(brand new) running about 18psi
  • Injectors are Bosch 6x.010"
  • FMIC, 2.5" pipework
  • Ported & port matched exhaust manifold to head.
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What fuel pin is in the pump?
No smoke and low boost does suggest lacking fuel.
Where is your EGT gauge plumbed in?
Fuel pin as below photo(unknown source as previous owner installed)
EGT gauge is about 80mm post turbo in exhaust pipe.


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OK, close to full travel. How much of a mark on the straight section of the pin? looks like it could do with some lube in there as well.
With the EGT post turbo the readings will be a lot lower than pre turbo which is what most use.
Thanks mate. No marks on the flat part of the pin as there was 3 x copper washers in there which would have replaced the original plastic ones.... I've now removed those and getting full travel into the depth of the groove.
I've found some more issues.... gov spring in the IP does not look anything like a 3200 spring(glad I bought a new one just in case.) and the slide pin was stuck and not moving in/out. Im unsure if the the O ring in there is the correct size or if the top cap that gets held in by the allen key nut squashes it to much, putting too much pressure on it thus not allowing it to slide.
Hopefully the photos below can give a better idea of what's doing with the slide pin, but need to fix this and I think I should be right.
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