[464]

Last year, before I changed the AIS motor

the Bronco used to idle as low as 650-800 rpms. It also got mileage so good that it had some board members doubting my truthfulness. Ever since I changed the AIS motor the idle barely goes under 1000 rpms hot, and takes forever to idle down after start up.

When I tossed the new throttle cable in today (also put the new Jacobs dist cap on too) I put my old AIS motor on and lo and behold the idle came down to 850, maybe even a little lower. I lubed all the cables; kickdown, throttle and cruise with silicone spray and checked for binding. There didn't seem to be any.

The Bronco's fast idle is down from 1800 to a more reasonable 1200-1300 and it comes off real quickly without having to blip the throttle. Drive away real smoothly, less clunking on the drivetrain and accelerates at least as well (maybe even better than) as before with the new AIS motor.

Is 850 or 1000 the warmed up idle on an EFI 86 5.0 litre ? Am I nuts going back to my old AIS motor from the brand new Ford one. I aims to try this out for a couple of days and see if the mileage goes up, stays the same or goes down.

Thanks for any advice you may want to give me

Sixlitre

 

[Steve83]

800 sounds right - is your emissions sticker still on the core support? On EFIs, it might not specify the idle speed since it can't be adjusted. I'd stick with the old one - why'd you buy a new one anyway?

 

[464]

Bought it because we were trouble shooting with my wallet(instead of logic) last Winter during the fuel pump problems. Want to buy it at full dealer cost ?

Sixlitre

 

[547]

I had the same problem when I changed mine. But the other one was defective.( wires were all burnt?) Don't know how that happened. Then I did my engine swap all better. I idle in park at 800ish. and in gear 675ish.

 

[464]

Yeah the in gear rpms sound like mine (now, with the old AIS motor in). Mileage seems to be up in a big way and there's less clunking and strain on the drivetrain with the lower idle and fast idles.

First tank was up 2 1/2mpg, but got corrupted when I burned off my air pump hose from near the converter and developed a leak. Capped off and clamped the bung on the pipe yesterday and I'm back ready to do another mileage test.

Took the rubbing and polishing compounds to the yellowed plastic centers of the rear wheel center caps and it became clear again. They look great.

Sixlitre