Rough Low idle to no start | Ford Explorer Forums

  • Register Today It's free!

Rough Low idle to no start

ConcealedLegend

New Member
Joined
October 2, 2020
Messages
3
Reaction score
0
City, State
Jeanerette, Louisiana
Year, Model & Trim Level
1999, Explorer
So recently I replaced the ac compressor on my 99 Explorer with a bypass pulley, now I’m having an issue where the engine would run rough down below 500 rpm and stall if I didn’t have pressure on the gas. I pulled off the throttle body and sprayed it down with cleaner even though it didn’t seem dirty, and adjusted the idle bolt forward until I could see sunlight past the flap when closed. When I ran it like that it idled a lot higher, up passed 1k, and would bounce up and down. I further adjusted it and now it will not start.

Any suggestions are greatly appreciated.
 






TL;DR: Just replacing the compressor with a pulley shouldn't cause this unless something else went wrong.

It would be good to list your engine and drivetrain in your profile "trim level" info as well as your sig. I don't know the cause for certain so will just throw some ideas out there... but I would try to return the idle bolt to its original position for the time being.

Was it running fine before the A/C delete or running bad already and a bad compressor was suspected? IF it started surging at too low RPM at idle every time the A/C compressor kicked on, that was the primary symptom I observed when my IAC valve first started getting gunked up enough to need cleaning.

Was the pulley the exact same size, or is it possible it is out of the range of adjustment (or worn out) the belt tensioner can compensate for? Did it run okay initially, and now possibly the belt is loose and slipping on the alternator so it's a low voltage condition? I was under the impression that there are no further adjustments needed, so is it possible the pulley is bad, or misaligned badly enough to cause severe drag (so now probably bad anyway)?

Did it really need a bypass pulley? I may be thinking of a different vehicle but I thought you could just use a shorter belt if you wanted to bypass the compressor?

Did you do anything else under-hood at the same time, or possibly disturbed a vac line that is now off or cracked? Disturbed a wire that's now unpluggd or shorting out? I'd hook up a scan tool with live data, check for OBDII codes, temp sensor reading, and look at fuel trims if you can get it running again, though even without it running you might see if position sensors are working trying to start it, then you have air, fuel pressure, right mix ratio (no vac leaks), and spark remaining to check.

You could charge up the battery, verify it holds charge (voltage near 12.6V) once off the charger (is it cranking strong?) and try to start it with the belt off, run it just long enough to see how it runs without the belt and new pulley involved, then shut off before it drains the battery.
 






Featured Content

Back
Top