intermittent idle

[loki]

Sounds like you've used two different-sized fuel lines along the supply side of the pump - bad idea, for it changes the flow rate

nope, the flow stays the same but pressure changes...

basic hydraulics

isn't that assuming the pump can push that pressure? if the fluid goes through a small enough opening the pump will at some point not be able to keep it up and the flow rate will come down no?

[after oil]

I'm almost having the same issue.
Just had IP fully rebuilt.
Idle set at 750 in D, comes slighting in P or N - maybe 800.
But occasionally I'll go to park and it comes up to 1000. Back to drive, and she's at 750. Doesn't do it every time - and appears to be only after driving for a while. But once it starts doing this - nothing will change till I shut the engine off. Fire it up right away - and it idles normally (ie, 750 in D / 800 or slightly less in P or N).
Funny behaviour!

BTW - didn't do this prior to IP rebuild - solid at 750, ever slightly higher in P or N.

I believe its related to the throttle position sensor (black unit with wire sticking out on top of IP - two flat head screws holding it in place)....but just guessing.
Mardy has 6 mo warranty so may have to go back to check it out, but will tamper with the TPS first and see if that changes things at all.

i think its not uncommon for idle to change between N or P and D. mine surely does that. what is uncommon, and what my van was doing (but seems okay now) was intermittent while in the same gear, rpms going up for second and then back down and steady for a few seconds and then up again...

Sounds like you've used two different-sized fuel lines along the supply side of the pump - bad idea, for it changes the flow rate

nope, the flow stays the same but pressure changes...

basic hydraulics

isn't that assuming the pump can push that pressure? if the fluid goes through a small enough opening the pump will at some point not be able to keep it up and the flow rate will come down no?

the IP is pulling mostly, not pushing. but the assist pump steadies that. there is still one more line, from the wvo filter to the heat exchanger,thats 5/16", and from the heat exhanger to the IP.. but the nipples are for 5/16" and i worry a bit that a 3/8" wont snug up on the nipples, thus allowing air in..