VE Pump tweaks, still looking for more power.

[RCCUMMINS89]

I didn't mean it can be turned in more than hang. I am surprised that it is hanging.......you sure the throttle isn't sticking by chance?

By all means, if it is hanging...... it is hanging, and runaway is near.


However.......I'm sure some will say differently. I have never seen a truck that (properly indexed, and the 3800 and 4200 springs are longer in stock form) one couldn't completely remove the idle screw......and then turn in the power screw til idle was right. AND NOT RUNAWAY.

I have also personally tweaked dozens of trucks that folks said were hanging........that I tested and were not hanging, cranked in the screw with the above method and the truck didn't runaway.



NOW...... please do not go out and do my above method and hope for the best. if it is hanging, it is hanging. But are you sure it is actually hanging, or is it coming down ever so slightly slower than before? Or maybe the throttle is sticking?

[oldestof11]

I am wondering if you have a boost leak in the intercooler or your turbo is going out...

[Turbo67]

I didn't mean it can be turned in more than hang. I am surprised that it is hanging.......you sure the throttle isn't sticking by chance?

By all means, if it is hanging...... it is hanging, and runaway is near.


However.......I'm sure some will say differently. I have never seen a truck that (properly indexed, and the 3800 and 4200 springs are longer in stock form) one couldn't completely remove the idle screw......and then turn in the power screw til idle was right. AND NOT RUNAWAY.

I have also personally tweaked dozens of trucks that folks said were hanging........that I tested and were not hanging, cranked in the screw with the above method and the truck didn't runaway.



NOW...... please do not go out and do my above method and hope for the best. if it is hanging, it is hanging. But are you sure it is actually hanging, or is it coming down ever so slightly slower than before? Or maybe the throttle is sticking?

Perhaps what I was experiencing was an overly concerned reaction to my perception of a slow returning idle.

Per your suggestion, I re-indexed the throttle shaft back to how it was when I bought the truck, one spline back from where I had been running it the last couple of weeks.

Then experimented with the main fuel screw. It had 5/8 of a turn left in it. The screw went from a little resistance to turning it, to feeling as if it were bottoming out against something. I locked it down there since I don't know enough about the inside of the pump to force it any further.

When I previously had the shaft indexed one spline, I backed the idle screw all the way out and it still idled high at 1100 rpm, today with the fuel screw now bottomed out and the throttle shaft back to "original", I had to turn the idle screw out to maintain idle or it would die. The fuel screw would not maintain an idle by itself without some input from the idle screw.

So, it has some more torque now and is back up to 23 psi at WOT in 4th gear. The boost raises quicker in 5th also, going up to just under 20 psi, whereas yesterday it would only achieve 16 psi in 5th at the same speeds. It definitely produces more smoke when rolling into the throttle, not really any smoke under higher rpm and WOT after the boost has risen.

I do have some wetting around the injectors. Note sure yet if it is the injection lines or the return lines. I did snug everything, but until I know what to tighten further, I don't just want to keep tightening. I will have to dry everything up and try to find the culprit(s). I mention this to ask the question: Can wetting / non-spraying leaks at the injectors cause great power losses?

[RCCUMMINS89]

You should be able to gain some more fuel screw with an aftermarket screw (hot screw) or welding a terd on the end of the fuel screw (inside part). The 205 pumps bottom out early, as they had a shorter fuel screw.


Have you ground on your stock fuel pin yet?

[Turbo67]

You should be able to gain some more fuel screw with an aftermarket screw (hot screw) or welding a terd on the end of the fuel screw (inside part). The 205 pumps bottom out early, as they had a shorter fuel screw.


Have you ground on your stock fuel pin yet?

Thank you for the pointer! Just looked up the power screw, and now realize that what I felt was the threads bottoming out where the o-ring goes. (I am a newbie to this stuff, but trying to learn as much as I can). I really appreciate the shared knowledge.

Have not ground the fuel pin. I am not scared of metal working or welding...just hate to practice on the only one I have.

[RCCUMMINS89]

We carry a longer power screw. They are more than long enough, if you feel it bottom out (with a "hot screw") stop, as the fulcrum lever is hitting the afc top.

[Turbo67]

I am wondering if you have a boost leak in the intercooler or your turbo is going out...

I certainly cannot yet rule any of that out. The turbo is pretty responsive, just seems to not make as much boost as some have said it should. I do feel like it has too much axial play and will probably rebuild it with a new thrust washer and seals. Assuming I can find a kit. My local Diesel shop carries AiResearch, not sure if they have Holset stuff.

Thanks for the input!

[Turbo67]

You should be able to gain some more fuel screw with an aftermarket screw (hot screw) or welding a terd on the end of the fuel screw (inside part). The 205 pumps bottom out early, as they had a shorter fuel screw.


Have you ground on your stock fuel pin yet?

Thank you for the pointer! Just looked up the power screw, and now realize that what I felt was the threads bottoming out where the o-ring goes. (I am a newbie to this stuff, but trying to learn as much as I can). I really appreciate the shared knowledge.

Have not ground the fuel pin. I am not scared of metal working or welding...just hate to practice on the only one I have.

Ok, looks like the next two things to try are a longer main power screw (Hot Screw) and an aftermarket fuel pin.
Both have been ordered.

If there is anything for me to try in the meantime, please let me know.
Thanks!

[Remps]

I'd bump the timing an 1/8" after you get the hot screw and fuel pin in. Once you get it (hopefully) cranking out the fuel, beware of letting off the throttle too quickly from wot, as these ve pumps like to 'backwash' the tip off the fss plunger with the small intercooled factory 6x.009 injectors. The more they are turned up, the more likely this is to happen.

[Turbo67]

The longer main fuel screw came in today.
Installed it just as RCCUMMINS89 recommended. Backed off the low idle screw, installed the longer fuel screw until the idle rose. For me this was also the point where the pin bottomed out. Backed it off about an 1/8 turn and locked it down. That gave me about a 1000 rpm idle. A little high, but worth the power increase. No tendency to run away or hang.

Wow! What an improvement! Large torque increase along with boost. Boost went from 23 psi with the previous tweaks to 27. It will also make the 27 in high gear, where as before, max boost was in 4th at the same speed. I am impressed with the power from this easy to install item.

Thanks for the help with this!

The fuel pin came in also, but I want to drive the truck some with just the longer main fuel screw and later install the fuel pin for comparison.

[RCCUMMINS89]

For clarification..........the hot screw bottomed out? If so, then that is max fuel you can get with the fuel screw.... as the fulcrum lever is touching the afc top inside the pump.

[Turbo67]

For clarification..........the hot screw bottomed out? If so, then that is max fuel you can get with the fuel screw.... as the fulcrum lever is touching the afc top inside the pump.

I turned it until I felt resistance with the truck idling. Tried turning it in a little more and cycled the throttle slightly to bring it off idle to see if things were binding. It would return to idle each time. Did not seem to be locking up anything...but did not want to force it. Truck was idling, backed it off about a 1/16 to 1/8 of a turn and it gained a few rpm on idle so I locked it down there thinking if it actually gained a few rpm backing it off, that was a better place for it rather than being jammed into something inside.

Is there a way to ensure it is bottomed and not just a tight thread?

Is there a way to relieve the fulcrum lever touching the AFC top to gain more fuel?

[RCCUMMINS89]

Ya, you're way in there then. BC847 notched his fulcrum lever... but I dont believe he gained anything. My truck will runaway if it is any more than it barely touching.