Problems with dead pedal between 25mph and 45 mph

[JAG1]

On 8/17/2018 at 6:01 AM, Mopar1973Man said:

I wish we would of knew that we have vendors with better prices than that. Also, I've been known to teach people how to change injection pumps over the phone. Ask @JAG1 he finally changed his first injection pump this summer. Typically I get a pump for about $1,200 then I charge about $120 to change out the pump being it takes me an average of 2 hours to change them. 

Yep Mopar1973man is a real wrench slinger does a dang good job on those VP's, but If I'm any where near the job and a bolts missing, get a flashlight and look down the intake tube. He beatin me to death over that even tho my own truck 

[015point9]

6 minutes ago, trreed said:

Return from where? Your airdog should already have a 1/2" return.  The return from the injectors/head won't return enough fuel to warrant a need for a 1/2" line.

Thanks... I was thinking return line from where fuel exits the head.  I stuck a camera down there via the filler tube.  Quite a drizzle of fuel.

[trreed]

I wouldn't worry.  The return from my regulator is only 3/8" and handles way more fuel than the head/injector return with no issue.

[AH64ID]

2 minutes ago, 015point9 said:

Thanks... I was thinking return line from where fuel exits the head.  I stuck a camera down there via the filler tube.  Quite a drizzle of fuel.

 

Yes at idle it will be the most fuel being returned to the filler tube, and the return off the head. 

 

5/16" is plenty. 

 

Honestly 1/2" hose is more than is needed for the AD 150 GPH pumps, but it doesn't hurt anything. 3/8" hose is more than capable of flowing the required fuel. 

[015point9]

2 minutes ago, JAG1 said:

Yep Mopar1973man is a real wrench slinger does a dang good job on those VP's, but If I'm any where near the job and a bolts missing, get a flashlight and look down the intake tube. He beatin me to death over that even tho my own truck 

All in gest...  I had to replace fass on the road.  @MOPARMAN1973 should look into private consulting for some mechanics,  up front cash on retainer.

[Haggar]

015,

 

The head return is "pushed" by the residual pressure of the closing injectors.  A bit of restriction there is not of a huge concern to the primary lift pump. 

 

In an engineering sense though, I have wondered what effect that pressure has when it tees into the return from the VP.....  could we run into a funny pressure at certain operating conditions with total flow to the tank.....

 

AH  that is a great point.  spill over is greatest at idle and goes down as throttle opens! 

 

Hag

Edited August 21, 2018 by Haggar
noticed AH's

[AH64ID]

1 minute ago, Haggar said:

In an engineering sense though, I have wondered what effect that pressure has when it tees into the return from the VP.....  could we run into a funny pressure at certain operating conditions with total flow to the tank.....

 

I've thought the same thing before. It would be interesting to see what's going on with some clear tubing in terms of flow into the T at different loads. 

[015point9]

When I put a camera down mine, I noticed lots of bubbles (air in fuel).  As my old return line used to exit real close to supply line.  Tank was about 1/4 full at the time.  When I replaced fuel module, new return line spits into module at a different angle now. Return fuel now "slides" down the module making less of a splash.    Also convinced me to fill up quicker, so I'm not sucking up as many bubbles.  I know airdog is supposed to remove bubbles, but have no idea how much or how bad they are.  Made me feel better anyways.  

(Can also report harbor freight camera doesn't like diesel)?

[AH64ID]

Yes the AD will remove any air that it can, but air bubbles will be generated at many points past the AD. 

Edited August 21, 2018 by AH64ID

[digidoggie18]

How do you guys feel about a sump instead of a draw straw? I was researching some options this morning and I love the sump idea but I'm still not 100% sold on it... I was looking specifically at the Beans diesel performance sump kit... I was wondering if anyone had issues with sumps and possible sloshing when fuel was really low causing issues.

[Mopar1973Man]

12 minutes ago, digidoggie18 said:

How do you guys feel about a sump instead of a draw straw?

 

I say don't. There is a legal issue with sumps (not DOT legal for bottom draw tanks). Then the risk of hitting the sump and ruining the tank. Once you cut that hole you commited to tank replacement if anything should go wrong. Replacement fuel tanks are very hard to find. 

 

@015point9 the point out of the VP44 is tiny. There is no need to increase that line. Left is the return.

Edited August 22, 2018 by Mopar1973Man

[digidoggie18]

Ahh ok, mine is pretty much road driven and gravel occasionally, nothing too big.. That's what the samurai is for lol. But, I will not be going sump then... I did not realize that and I appreciate the insight

[AH64ID]

Aside from any DOT issues a sump only has a few distinct applications. A modified basket is the best option IMO. 

[JAG1]

On 8/21/2018 at 8:06 AM, 015point9 said:

All in gest...  I had to replace fass on the road.  @MOPARMAN1973 should look into private consulting for some mechanics,  up front cash on retainer.

Yep Mopar1973Man is a real cell phone slinger too.... so many call needing advice he should get paid for each minute on the phone. He has helped me tons.

[dripley]

I have a modified basket and it will suck the tank dry.

[Mopar1973Man]

 

Even a properly cut straw will such the tank dry. 13 years and still no issues. Just plain old draw straw no basket or anything. 

Edited August 23, 2018 by Mopar1973Man

[digidoggie18]

Ok, so I put in a new lift pump from Napa and it sure as **** doesn't keep up whatsoever... Just at idle revving it and watching the fuel pressure to the VP it drops down to like 10 psi ish so I'm confident 55gph can't keep up. One question though, how does the return open in the VP?  It is a valve correct? Does it open based on pressure or flow? Or is the return just wide open pushing all excess that isn't picked up by the injection pump? I'm trying to rule out a possible VP problem as well if that's the case prior to dropping 400-600 doing an air dog... I want to be 100 percent sure that it will fix the not having enough flow  and low pressure issue. I'm not feeling too confident with this industrial injection vp44 personally... Are you guys confident that the lift is for sure my issue with still hitting that low of pressure? Could there be another issue that could cause that that I could check I.e. Possible air?  I really appreciate your guys help... I dunno why the **** the stock lift is rated for 55 gph when it can't even handle it.. It's it possible when I bought the new injection pump that it flows more than the oem pump? I'd like to have some more in depth conversing on the void possible. Anyone have resources on that to do i can learn more about it? On top of everything? 

[Mopar1973Man]

Just need a better fuel system. The overflow valve typically opens at 14 PSI. So any fuel pressure below 14 PSI the overflow is closing. It's completely closed by 10 PSI. As for the overflow valve typically they don't wear out. This still brings you back to getting a AirDog or FASS. Not going to change til you upgrade.

[digidoggie18]

Perfect, that's exactly what I was looking for... Just making sure I didn't have a relief stuck in the even if possibly another issue... Thanks for the help, you're the man haha

[dripley]

Dodge even quit putting them on years ago. My oe lift pump went at 150k and they gave me an in tank pump for $900 plus the tow bill. It was failing in just over a year.

Edited August 25, 2018 by dripley