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P400 in the Burb install

spdgofast

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Was the pump pressure not high enough to atomize the fuel on # 2 ? What was going on with # 1 and 8?
 

spdgofast

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So what did you have done to this pump this time? And what was the reason for no warranty on the work? and did they ever tell you what they did and what amount of fuel they claim it would deliver?
As I stated previously the pump only had maybe 1000 miles on it just not enough fuel so I just sent it to them and said do what you can to get me more fuel but use my .350 head and rotor instead of the .310 plunger head and rotor that you usually use. Then after I paid the invoice it stated no warranty on the head & rotor since it I supplied it. I thought I posted the flow numbers that they gave me earlier but here they are again. Let me know if you can't see them.
 

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spdgofast

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Well, that could have been the issue with the 2 goofy cylinders huh?
Some bad injection pump karma at ya?
I don't recall me doing anything to deserve any bad IP karma! I have over $3200.00 in my last 3 injection pumps. I guess I'm not spending enough for them?
 

spdgofast

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Oh and I bought them all from so called reputable pump suppliers/builders (Peninsular Diesel, Conestoga), yet they all told me to go pound sand when they fail, I would probably had much better results with a Bosch P pump warranty, but I guess it would not have needed to be modified, So it looks like Fellow Traveler has mad the correct decision.
 

spdgofast

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Sorry, I guess I'm just hating on the 6.5s right now. Especially the fact that I can't find anyone that can build a pump for one. And it looks like I'm going to have to carry a spare if I plan on any cross country driving. Or maybe I should just drive my Dodge. LOL!
 

FellowTraveler

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I would probably had much better results with a Bosch P pump warranty, but I guess it would not have needed to be modified, So it looks like Fellow Traveler has made the correct decision.
The P pump can be built on the kitchen table there is no shortage of parts and exotic internals too.
 

JayTheCPA

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Sorry, I guess I'm just hating on the 6.5s right now.
I feel the pain . . .

My mechanic made a comment that pretty much went along the lines of: 'Hey, you do a lot of homework, make good decisions based on the research, and put a lot of money into the Burb, so why did you keep the 6.5 and not put in a Cummings?'

Actually, once I got the motor itself settled down, it was good. Just continually got bit by other ankle-biters (some not so inexpensive) which finally pushed me over the edge.
 

WarWagon

Well it hits on 7 of 8...
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I think it is just dumping fuel in the #1 and #8 cyl, most likely not enough pressure from the IP to atomize the fuel is my thinking. The pump builder will most likely tell me that I have the injector pop pressures set to high which they are set @ 2250 PSI the pump builder recommends the pop pressures to be 1700 but I think that is just too low.
Pump builder ought to simply insist you run the pop pressure they built the pump for. I had them build me an injector set with their recommended pop pressure. Even on the bent up valve (very low compression) engine of mine it started way easier than the PIA to start high pop pressure injectors I ran. What does easier starting tell you about how much harder the pump has to work with high pop injectors? It also needed more advance on three (3) separate pumps to run without smoking white. The other pumps appeared 'worn out' with hard hot start problems. All because of the FBomb high pop injectors I thought was a good idea to run. I learned the hard way: it's not a good idea anymore on the "ULSD" we have now.

The high pop pressure may be the cause of the pump locking up. I am also in the bad pump club, but, a failed pump governor ended the useful life of my engine at 4300+ RPM before other things could.
 

6.2 turbo

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2250 psi is not really that high. I will be building a set here soon at 3200 psi or higher. The only downside is no hot starts,if the head and rotor are worn.
 

WarWagon

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"I maybe missing something here as I suffer from "some-timers" but I transfer fuel from my aux tank exactly into the main tanks fuel fill as I drive for many years now and never ever had such an issue? So why would the small fuel return cause an issue? Lest we forget the fuel gets sloshed around the tank and surely air bubbles do form unless foam or bronze wool are incorporated into the tank like in a fuel cell.
Not talking about a Aux fuel tank feeding the main tank here: just the idea to use an adaptor in the fuel filler that an aux tank would use for a fuel "return".

Nope, you've got an apples and oranges thing here. Pushing fuel back to the tank from the LP vs the designed fuel return system post IP. I'm late to the thread, but he did say 'from the LP.'
If you have a dedicated regulator that has a return/bypass line off of it you don't have to worry about it siphoning off when it sits overnight. You can also have it feed into the filler neck with no issues. I have a system setup like that on my stepside. Can sit for months and have no issues.

The other nice thing about a full flow bypass is the pump can run flat our and the engine just pulls what it needs.
FWIW: School of hard knocks advice on air here.

What we are talking about is air getting into the fuel injection system. Is the bypass valve on the LP/bypass regulator going to have an air-tight seal every time? Little debris, say from pump wear, sticks in the valve once or hammered into the valve is all it takes. I suggest the answer is "no" and it will be a bastard to find the air leak if it quits sealing. Mainly because it's a combo of two problems: 1) a small return regulator valve leak won't affect the pressure as the pump has enough volume 'in reserve' to not notice. Aka the valve is open some in normal operation all the time anyway. So return regulator passes tests as it appears to work fine per the fuel pressure gauge. 2) An air source (return in fill neck) above the fuel in the tank needing just that one valve to leak to drain the fuel system.

The return style regulator being at the frame rail or engine height may make a difference in allowing air to "break a siphon" and drain the fuel system. If the return is submerged in fuel the return regulator valve can leak all it wants, but, it can't introduce air into the fuel system when the engine and LP are "off".

Even if one uses what I suggest is a 'bad idea' IMO it can help troubleshooting to simply keep in mind the weaknesses should hard cold starts start happening. Simply ask 'is what I am doing a possible source of air if mechanical valve starts leaking a little?' And then start throwing parts at it there...

@KrisML I agree with the Full flow bypass allowing the pump to run flat out and cooler. The inertia of the fuel in the fuel line is a factor small or not.
 
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WarWagon

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2250 psi is not really that high. I will be building a set here soon at 3200 psi or higher. The only downside is no hot starts,if the head and rotor are worn.
It's 550 PSI over what Conestoga Diesel is recommending for whatever magic they do. Just to get the flow numbers maybe? Stock 6.2 pumps sure don't like the high-pops I ran. I forget what popular high-pop number I was running offhand.

I would be interested in what you are doing to the pumps, if anything, for the higher pop pressures?
 

Twisted Steel Performance

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2250 psi is not really that high. I will be building a set here soon at 3200 psi or higher. The only downside is no hot starts,if the head and rotor are worn.
I haven't played with high pop injectors at all, my pump builder is dead set against it for the pumps I have built. My injectors are set @ 2100 for the high output DB pumps.. maybe because it causes stress inside the pumps, I haven't investigated it, he says more volume @ 2100 than higher pop..
 

Will L.

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Having them match the intended build is important.

When running higher pop pressure you loose some fuel volume, but increase the atomization of the fuel, so what goes in burns cleaner and faster.

What nozzles you are running makes a big difference also. Larger nozzles like 303 vs 311. If you run the same pump with same nozzle size and just increase the pressure, you might not like the results. If you have a tired, stock pump and do it, you will not like it.

The injection pump ramps the pressure up well above the level of injectors. I wanna say something like 4500 on a good condition pump. The higher the pop pressure, the more resistance to fuel flow there is, but it is like building more boost from a turbo. Yes more restriction to the exhaust gasses exiting, but the net gain is larger.

Getting the timing right is key. And every little bit more the injectors resist, delays timing. So you have to advance the pump more to get the same net timing.

The pressure levels of old are no good, as the fuel viscosity is different, so my old numbers are junk now. What makes that even worse is how bad the fuel viscosity fluctuates through out the year in some areas. An expected problem for folks in real winter areas, but even non frozen parts can get movement. This is because in many areas they run higher content of methonal/ ethonal to fight emissions more —well thats the story- profit is the real reason. They pay way more for crude than corn.

If you are just buying a set, without a doubt go with what your pump builder says.

Pop pressure is something that a person can play with at home if you invest a bit of cash to do so. You need 2 sets of injectors to make it easier. And both should be same nozzles and age. Get a set if bodies from junkyard, and buy 2 new sets of nozzles.
Finding the shims is harder than it used to be. @ak diesel driver how did your diy shims turn out?

Fleabay sells testers for $75, but the gauge is not the most desirable one. A liquid filled tigher range gauge is better. Making your own is an option too.

Build the 2 sets and drive one recording results. Mpg, 0-60, etc. keep in mind the timing thing. Once you dial in what works best for your uses, set up the other set of injectors. Then instead of diesel, run some non detergent 5wt oil through them before storing. This is crazy important for injectors, injector pumps, and even the tester. The corn juice in the fuel is not good with what it leaves behind.
Then you are set for the next 200,000 miles. Keep a copy of your results with the tester for years down the road when you swap injectors. Having a fresh set on hand is not a bad thing. Keep in mind, a new ip at the beginning vs @300,000 miles on engine compression, and ip wear, you won’t get same results.

Pop pressure and it’s related timing is tuning the engine. Change your boost levels alot and that alters it as well.

There is a ton of different opinions, but people use their rigs different. Better fuel in certain areas, altitude, flat land vs mountains- have different affects, let alone turbo,etc. How far down and how long you hold the skinny pedal plays in too.

I used to love experimenting and an excuse to turn a wrench with buddies. So doing this was fun. If this is all work and no play for you- just call your ip guy and read off some credit card numbers...
 

spdgofast

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Before I pulled the pump and sent it to Conestoga I was running new 311 nozzles popped @ 2750 and it ran great but didn't like to start when hot and I believe I had a bit of a "lean" fuel condition contributing to the low EGT's I believe.
 

Rockabillyrat

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Higher pop pressure is pointless in an IDI if you are after more power. Greater atomization creates smaller fuel droplets. Which have a greater surface area of fuel exposed to the air in the pre combustion chamber. While this is great for combustion in the cup. You will end up with less unburbed fuel reaching the main chamber. Not to mention the velocity of incoming air tends to take the smaller droplets out of suspension.

Lower pop pressure creates bigger droplets. With less surface area exposed to the air in the cup. So less fuel is consumed in the cup and more can reach the main chamber. The more fuel you can burn over the piston the bigger the "push" you will have on it.

Alot of people forget that the pressure differential at the cup throat is responsible for the atomization of fuel droplets left over in the cup when it reverses flow. It's a mechanical version of pilot injection found in a common rail. The right fuel rate curve, pop pressure, and cup style are all key parts to the injection process. All 3 are important to one another and you shouldn't focus all you attention on just pop pressures.
 

93detroit

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So I guess my marine tipped injectors popped at 2300 (with Optimizer n/a precups) and a 90k mile injection pump shouldn't start or run well- but it does. Not being smart, just wondering why I'm lucky!
 
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