Grayson's HDJ81 Build Thread (1 Viewer)

[Delta VS]

Unfortunatly none of them ever posted what did resolve their incline stall issue if they ever fixed it.

Well don’t be like them, please. Interested to know what solves it for you.

 

[kendgray]

Alright, after tinkering and testing for the last few hours I'm optomistic I may have got it sorted.

TLDR; I think the IP's on these 1HD-FTs are sensitive to being driven at RPMs outside of spec. If RPMs dip too low d/t load on the drivetrail or accessories at some point the IP cannot create the suction needed to draw fuel, especially when the pump's head is simultaneously increased d/t being on a steep incline.

I hadn't noticed this before but tonight while driving around looking for the steepest pile of dirt I could find in some nearby construction sites I realized that my idle RPM is terribly inconsistent and that its often lower than I had given it credit for. It normally would idle around 700-750 RPM but it was occasionally dropping all the way down to just below 600 RPM in drive and would only pick up to maybe 625 in neutral (spec for the A/T is 800 +/-50 with all accessories off and the truck in neutral). Once I got the truck up on an incline, with the drivetrain loaded up mid climb and the wheel turned to load the PS pump RPMs would drop all the way down around 400 if I let off the throttle. If I shifted into neutral and backed off the wheel the RPMs would pop right back up to around 600.

The idle adjustment screw wasn't even making contact with the IP linkage so I cranked it to give me dead on 800 RPM at op. temp on level ground in neutral and readjusted the kickdown cable to accomodate this change. Now (at least on my construction site dirt mound) on incline with the drivetrain and PS loaded RPMs only drop to ~725. Obviously it's far too early to call this fixed but I'm hoping to get back out to the Owyhee's next weekend for more rigorous testing.

 

[Delta VS]

Alright, after tinkering and testing for the last few hours I'm optomistic I may have got it sorted.

TLDR; I think the IP's on these 1HD-FTs are sensitive to being driven at RPMs outside of spec. If RPMs dip too low d/t load on the drivetrail or accessories at some point the IP cannot create the suction needed to draw fuel, especially when the pump's head is simultaneously increased d/t being on a steep incline.

I hadn't noticed this before but tonight while driving around looking for the steepest pile of dirt I could find in some nearby construction sites I realized that my idle RPM is terribly inconsistent and that its often lower than I had given it credit for. It normally would idle around 700-750 RPM but it was occasionally dropping all the way down to just below 600 RPM in drive and would only pick up to maybe 625 in neutral (spec for the A/T is 800 +/-50 with all accessories off and the truck in neutral). Once I got the truck up on an incline, with the drivetrain loaded up mid climb and the wheel turned to load the PS pump RPMs would drop all the way down around 400 if I let off the throttle. If I shifted into neutral and backed off the wheel the RPMs would pop right back up to around 600.

The idle adjustment screw wasn't even making contact with the IP linkage so I cranked it to give me dead on 800 RPM at op. temp on level ground in neutral and readjusted the kickdown cable to accomodate this change. Now (at least on my construction site dirt mound) on incline with the drivetrain and PS loaded RPMs only drop to ~725. Obviously it's far too early to call this fixed but I'm hoping to get back out to the Owyhee's next weekend for more rigorous testing.

Very nice!