damage31

1991 with 3.1, I just replaced the injectors after 100,000 miles because I was having a bit of a starting issue. Minor, but annoying. For all I care the car ran ok other than startup cold. It seemed like the old injectors were leaking down after shutting off the car, flooding it out somewhat.

So I picked up a set of injectors from South Bay and put them in today. Stock replacements but they are ford injectors which, I guess... work?

What happened after the install surprised me:
idle speed at cold startup was 2500 rpm in the tach.

After a few restarts and warming up a bit, was down to 1500 which is still high. Recheck for vacuum leak or missing vacuum connector was ok. Took it for a 45 minute drive average speed was 45-50 mph. Coming to a stop in gear tach was at what I would say is 1050rpm, which is still a little high.

What I am mainly wondering is, I would think this would settle down to the 850 area by now but it’s still idling at 1500 when warm out of gear.

Is there something I missed or didn’t do? Battery was disconnected during install, so I expected some learning but it still seems high, as I’m used to like 1200 rpm when cold, and 750-800 rpm when warm.

drdave88

iTrader: (3)

My guess is you're missing a vacuum leak, unless a sensor on the throttle body was damaged during removal/installation, that would be where I'd check again. Take some carb cleaner and start spraying around any intake gaskets or vacuum hoses. They're all likely old and brittle and may have cracked

RBob

iTrader: (1)

Should do an idle learn as the battery was disconnected. See (at least) the first three posts in this thread:

https://www.thirdgen.org/forums/v6/1...dle-learn.html

RBob.

damage31

When I got home I thought, ok let go over this again. So I rechecked everything, and look for vacuum leaks and figured I would clean the IAC just for kicks and do a relearn.

Long story short I broke the IAC, but I’m of the impression that it was not working properly, and was stuck open for whatever reason because before I broke it it wouldn’t seat fully closed even after cleaning it.

Its getting hard hard to get parts for this- I happened to get lucky and AutoZone warehouse store near me happened to have 1 in stock. Napa, O’Reilly and Pep boys had nothing- would have been special order.

So with a new IAC installed, and doing an ALDL relearn things are slightly better but still not 100% as before, idle is still a smidge high at 1000 on the tach in gear but manageable for now. At least now I know it’s not the IAC. When the iac is closed and unplugged it’s idling at 500. I don’t hear/feel any sucking from the closed IAC port when it’s unplugged.

Not to compound things but I’m going to do a new coil and distributer and plug wires next week - that is, if the idle can be brought down to get it to time properly- if not I’ll just do wires and coil until this can be worked out

damage31

Fun fact: its back to normal. I think. At least for now it is.
Interesting how I got here though. I drove the car in to work, and idle was ~1100 in drive all the way in.
I went to lunch, and sat in the car while eating. Left it in drive while I ate. Not sure why, but I did.
After something like 5-10 minutes, the service engine soon light came on.
Uh-oh. didn't expect that. But I guess, ok, what now?
Put it in park, shut the car off, and restarted it.
Idle is now normal. totally normal. SES light is off.

Checked codes on my way home just for kicks, and code 35 was set. "DTC - 35 IAC problem or idle error"
Figures. Well, I'm not surprised and since the light is off again, I don't much care.
I think it just finally worked itself out on its own.