Fordbragg

My rpms run around 1700-1800 in park or neutral and about 600 in gear. Obviously, if I try and raise the in-gear rpms, the park/neutral will go up as well, and vice-versa. My timing is fine and I'm running out of ideas. It's a '91 5.0 Lariat with EFI.


Anyone have any help they can give?

wde3477

Not knowing your level of expertise - did you check the timing with the SPOUT connector out?


Have you cleaned the Idle Air Control (IAC) solenoid to ensure it's not stuck?


Checked for vacuum leaks? Carb cleaner carefully spritzed around can flush these out.


The idle screw stop in the butterfly should not need adjusting...


Good luck, and keep us posted.

fltdriver

Pull your codes, x2 on cleaning the IAC but do the throttle body as well. I don't take it off to do the inside unless it's really caked in there as it gums back up right away, just make sure you get both sides of the butterfly valve as well as the edges (most important is the edges). Use TB cleaner on the TB and IAC, hold the IAC plunger down so it doesn't fill with fluid, use a toothbrush to get most of it and a pipe cleaner to get the plunger rod and the hard to get parts of the BV edges. Also grab a can of QD Electronic Clean and do the connectors, spray the male end and wipe the prongs, then respray and insert into the female end a number of times, this will clean the contact points off.