My addiction

[TFaoro]

59 minutes ago, Mopar1973Man said:

 

The internal vane pump does increase pressure internally to the VP44 but at the same token you take the risk of blowing the front seal out of the VP44 dumping diesel fuel in the crankcase. Matter of fact I just talked to a guy yesterday about that and he admitted that had a partial blockage of the FASS return line and fuel pressure went to 32 PSI and at that point blew the front seal of the VP44 out. 

I'm curious how you get a blockage on the return.....

[Dieselfuture]

38 minutes ago, TFaoro said:

I'm curious how you get a blockage on the return.....

Maybe he modified his fuel basket and something happened to return line. That brings another question @Mopar1973Man or someone that can check on fuel temperature at vp. Since I'm returning fuel to the fuel basket,  I want to compare fuel temperature to someone that is returning to the filler neck.  I've seen my temperature as high as 160 f. But I'll double-check.

[Mopar1973Man]

High I remember seeing is 120-130*F realm for fuel temps. I might see 140*F after being parked awhile and just key on and hook up the Quadzilla. I'm not returning to the fuel basket for the AirDog 150 but I am returning to the sender basket for the VP44 and the return rail. I draw out of the center of the tank with an old school draw straw. 

[rogerash0]

I found the big CF thread with all the arguing about pressures, the 14psi fuel return, your youtube videos, and your page "Fuel Pressure Specification For Bosch VP44 Injection Pumps".

 

I didnt get all your replies until just now. I threw in the 30psi AD spring and it was running 35-36psi. I have driven on it by mistake at 40psi for hours previously, because it shipped /w a 40psi spring in it, and the guy that installed the motor never checked the pressure & I didnt go through the Edge to check pressure until I got home from his shop some 2 hours away. Point is, I test drove the truck at 35-36psi just now, figuring if it didnt blow prior @ 40psi, it probably would be ok now. Results: The truck no longer has a choppy surge/buck when I let out of WOT on lvl 7 Edge Jwa Comp. It was bad enough I never ran level 7 as a DD tune because of this. With the 50hp injectors in, and the trans working loads better, and smaller tires on, Im burning pretty clean now. I have been running at lvl 6 as my DD tune for a number of months.

 

I got the AD at 25psi at idle now. Im going to go see if I still have the surge on lvl 7. It did seem to run a tad bit better or smoother, but it was so minute it could have well been my imagination. I did drive teh truck for about an hour today, prior to doing any AD spring changes, to ensure I knew how the truck was driving exactly, today.

[Mopar1973Man]

That's the thing that is weird about fuel pressure I've had some report blown front seals at as low as 28 PSI and seen others get away with 40 PSI and more to the VP44. I still do not suggest anything above 20 PSI. Because you only going to get so much to flow out the return hole if you look its rather small. 

 

[rogerash0]

Agreed, I took a long firm look at that in your post. If its 25 at idle, it'll be 22-23 whilst I drive with a full tank (under moderate 10-25% throttle), another 1psi lower at half tank and below, and my Edge gauge reads 1 psi higher than one from the hydralic store that was $25. So, I'm going to call it close enough to 20. I have a spare II VP SO that I bought and its just sitting, because it didnt fix my hard start symptoms I was troubleshooting. It also didnt run a lick different than the VP on my truck right now. So if this one craps the bed, atleast I can use the other one I paid for. We should find out on this 2400mi journey I have coming up. I put the II VP on, and back off, so I've done it twice recently, should I have to do it on the side of the road. Dont want to, but I'll be prepared.

Edited October 9, 2017 by rogerash0

[Mopar1973Man]

Sometimes wonder about peoples fuel systems. Why am I the lucky one with only a 1-2 PSI drop from idle to WOT? This is verified with two different gauges too.

[rogerash0]

It drives me insane. On my old motor (53 block that cracked), with the AD100, Old school monochrome edge jwa, these same injectors im running now 8 hole "50hp" (dont rly know), --- all stuff that was on the truck when I purchased it --- The pressure never dropped until I went to Colorado Springs where it was 6k altitude. There it was 13-15psi. Otherwise it was rock steady 16-17psi no matter what. Thats the reason why I bought the AD165 4G rather than Fass, because the AD pressure never dropped. Not my new one, even utilizing the old base like I am. Even with a 200 motor on it. And a 10 micron filter, no difference (Im back to running a 2).

Edited October 9, 2017 by rogerash0

[rogerash0]

Sure enough, level 7 remains useable. Pressure drop from 24 idle to 15-16psi WOT on level 7. Also a big deal was with the lower VP pressure, I was "snuffing" out the truck with DDP 120's. I would go WOT then let out real fast, and the truck would die. I had to crack the lines. Did this enough to burn through a starter. If I was real easy getting out of the throttle it wouldn't die. I've been getting better at not snapping the throttle closed, I seldom do it anymore, to prevent turbo bark & its a smoother ride. But I even killed the truck in traffic one day from a corner stop to 40mph; let out of the pedal and she died right there just short of the intersection. Really sucked. I dont remember my VP pressures from then, but I recall they were sub-20 at idle. I have photos showing 10 and 12psi at WOT with those injectors on the mechanical gauge to pease AD.

Edited October 9, 2017 by rogerash0

[Dieselfuture]

3 hours ago, Mopar1973Man said:

Sometimes wonder about peoples fuel systems. Why am I the lucky one with only a 1-2 PSI drop from idle to WOT? This is verified with two different gauges too.

Same here. You can't cut corners on fuel system.

3 hours ago, Mopar1973Man said:

High I remember seeing is 120-130*F realm for fuel temps. I might see 140*F after being parked awhile and just key on and hook up the Quadzilla. I'm not returning to the fuel basket for the AirDog 150 but I am returning to the sender basket for the VP44 and the return rail. I draw out of the center of the tank with an old school draw straw. 

That's kinda what I'm wondering about someone like me sucking and returning fuel from basket vs you or anyone that sucking cooler fuel, and how it may effect vp. 

[Mopar1973Man]

On the Quadzilla it would of trip the warning light for fuel temp. The 160*F temperature is the factory setting for the Quadzilla but the actual fuel temp error doesn't happen much higher...

 

 

Edited October 10, 2017 by Mopar1973Man

[rogerash0]

I was using the drawstraw that came on the truck when it had the AD100 on it. Went to sump to see if it would fix, but to no avail.

[jlbayes]

17 hours ago, Me78569 said:

must be a tps issue then.

 

I will cut you......

 

16 hours ago, Mopar1973Man said:

 

The internal vane pump does increase pressure internally to the VP44 but at the same token you take the risk of blowing the front seal out of the VP44 dumping diesel fuel in the crankcase. Matter of fact I just talked to a guy yesterday about that and he admitted that had a partial blockage of the FASS return line and fuel pressure went to 32 PSI and at that point blew the front seal of the VP44 out. 

 

My point was the increased inlet pressure was a wasted effort. I had 30psi inlet when I first put my AD II on straight out of the box......

 

14 hours ago, Mopar1973Man said:

Sometimes wonder about peoples fuel systems. Why am I the lucky one with only a 1-2 PSI drop from idle to WOT? This is verified with two different gauges too.

 

My ADII 165 only had a 1-2psi pressure drop with my strung out vp setup. About 200hp over yours. I have no idea why it worked so well.

 

@rogerash0 the "snuffing" you are referring to is actually cavitation when the pump is attempting to slow down and the fuel is cut off. You are the first I have seen state they have remedied it with high inlet pressure. Be very careful dumping off the throttle like that (I know it is not always as simple as it sound). It can shear the cam ring pin. Dead vp afterwards.

[rogerash0]

Interesting. Thanks for the good tip. How do others solve the cavitation problem? 

[jlbayes]

Not dropping off the throttle fast. Or if you have to...burp the throttle a few times while rpms are coming down.

[TFaoro]

On ‎10‎/‎10‎/‎2017 at 6:55 AM, jlbayes said:

@rogerash0 the "snuffing" you are referring to is actually cavitation when the pump is attempting to slow down and the fuel is cut off. You are the first I have seen state they have remedied it with high inlet pressure. Be very careful dumping off the throttle like that (I know it is not always as simple as it sound). It can shear the cam ring pin. Dead vp afterwards.

I noticed higher inlet pressure kept mine somewhat happier going from 15 to 22psi on the inlet. It wouldn't die quite as easily.

[jlbayes]

I killed mine with 25psi inlet pressure. With 7x.010s and a tst pm3. Never had it happen with the tst comp and 6x.013s. Tell me how that works......

[Mopar1973Man]

What the problem is that the cylinder pressures are high from the boost pressure so when you dump off the throttle rapidly the pressure is forced passed the injectors pintle and air/gases get into the injection lines. So as @jlbayes mentions blipping the throttle a few times this raises the line pressure up again to possibly blow the air back out of the injection lines before landing at idle RPM. This is normal for high boost engines. 

 

[rogerash0]

I don't quite buy that theory moparman, no offence. Not that I'm ignorant or unwilling to change my mind.... and it makes sense, but the truck not dying with high vp inlet pressure told me it qas more of a pump problem.

 

I was only pushing 43 or 48psi, I'd have to check my logs at home.

[Mopar1973Man]

Hmmm... Typically that is what the big boost guys are fighting with stalling. There was a member here ISX that did the calculations for cylinder pressures and found that around 60 PSI of boost you could exceed the pop pressure of the injector causing compression gases to push back. But that what I had to give for info...