leathermaneod

Thanks to all for the helpful replies :-) I will mostly likely leave it alone then.

Hi all, So I recently upgraded my ancient FASS lift pump to a Fuel Boss mechanical lift pump from Glacier Diesel Power. It has a bypass valve that allows fuel to return to the tank at a certain psi. I bought a "Tuning Kit" for that valve so that I could set the pressure exactly where I want it. I have been trying to get it just right but I keep ending up with it either a little lower, or a little higher than I want. I need help figuring out if I am looking for the wrong number or what, and where I should set it. I have in my head that anything over 20 is too high but at the same time I don't want it to get too close to 15 either lol. After messing with it for a few hours today I decided to er on the low side. I tried all kinds of combinations of the spacers and 2 different springs the come with the valve and tuning kit and can't find a happy medium. Everything is either too high or too low. I ended up with idle at about 17-17.5. And IIRC that puts it at about 18 at 65mph. Those numbers are the approximate average between my two gauges. I have an autometer mechanical gauge with isolator on the pillar and a Vulcan test gauge from Geno's. The test gauge always reads about 1.5 psi higher than the autometer. Since the pump is mechanical, the pressure generally goes up from idle, but it does dip very slightly at first (about 1-1.5 psi) If i stomp on it or when letting the clutch out without throttle. Basically until the rpms catch up with the fuel demand. I wanted it just a touch higher but I just can't get it there. Next step up puts it at 18 or 19 idle and then it gets over 20 up to about 22-23 at 2400 rpms. That just seems too high to me. What do you guys think? Knowing that it will dip about 1 psi or so, would you go on the high side of 19 idle and 22-23 at 2400rpms, or would you go lower with 17 at idle and around 19 at that rpm? I just get concerned when it goes over 20 psi, especially since I know it rises with rpms and Im not sure how high it will go...I mean, what if it hits 25 or more? But I also don't like it anywhere close to 15 either. Anyway like I said, what would you guys do? I know Im worrying about this too much, but I'm really OCD and I need the opinion of someone with more experience. Oh by the way, these numbers are all with my Smarty on SW5 so they might go up slightly with it on a lower setting. Its not much though. Thanks! Nate

Wow that's crazy how complicated that all is. Pretty cool how Timbo figured out how to do it mechanically. Thank you both for taking the time to explain all this! Greatly appreciate it!! Can't wait to get the switch and get installed!

I'm confused, what is the IVS? And I have a stock APPS as well does that mean it won't work for me? How did he resolve the issue? I was going to replace my APPS with one from Geno's a while ago because I got a momentary dead peadal and a P0121 code while on a long trip from NY to PA. I cleared the code and have had no issues since so I sent the new APPS back to save the money.

Thanks for the info ME78569, and for letting me know about that switch! I just bought it :-)

Sweet! Thanks for explaining all that! I assume from what you said that if your are in 6 cyl high idle and want to check the temp you could just switch to mpg to look at the temp gauge, then switch back? Also though of another question. Do you have any idea how a smarty with timing adjustments acts with the advanced timing at startup? And also do you have any idea how it would act with the mpg mode? What I mean is how does the ecm know which to follow? Or does it still advance even further when cold?

I have a few questions about the switch. I am already sold and will order one as soon as they are in stock again by the way. Isn't there a danger of overheating in 6 cyl high idle mode since the temp gauge is disabled? Also, how hard is it to change modes with the truck running? That seems like something you would want to do pretty often if I am understanding things right. For example, you go to a job site in 0° weather and want high idle when you get there, but the instructions page says you don't recommend it. What happens if you do it too slow and the code is trigger? Can you turn the MPG fooler on and off with the truck running? Also, what happens to the other three cylinders in 3 cyl mode? Do they not receive fuel?

sounds great thank you very much!

There was, but it seems I hesitated about an hour too long :-(

ok thanks!

I saw that. Any idea when will there be more available? Thanks BBHD!

nvm I found it

Where can I get one of these kits? I've seen high idle kits online but never the actual Mopar1973man one for sale anywhere?