idle problem?

[bert296]

ok my 93 4.0 idles between 2000 and 2500 and when its not doing that it surges up and down from 800 to 1200 roughly im at my wits end with this thing ive tried everything i can think of to fix it it wouldnt bother me but when driving it down the road it holds at like 2500 so it goes to fast in town roads PLEASE HELP

 

[Brandon Nootenboom]

My 91 4.0 did the exact same thing, it was the idle control valve. I'd pull it off and clean it to get ya by, a good cleaning only lasted about 5k for me before I had to put a new one on for about $50

 

[bert296]

i put a new idle air control valve on today it did help ALOT! doesnt hold at 2500 when driving, drives niceee! but now idles at 1400 (what should it idle at?) and surges between 1200 and 1400 only when its in gear and clutch in pop it in neutral clutch out going down the road idles at 1400 if i just put presure on the shifter into gear it starts reving up and down any ideas??

 

[Brandon Nootenboom]

Do you have a check engine light on? When I did the 91 it still idled about 1200 with surges, I have a 97 4.0 now and I replaced the valve on it too but now my check engine light's on and the codes read my mass air flow sensor is going whack so it's idle is still off. Same thing though, coasting in neutral it's higher than at a stop but mine surges between 500-1100. Maybe your mass air flow sensors going out? I believe they're suppose to idle at like 700-800

 

[Ak907Girl]

I'm having an idle problem in my 93 2.3L Manual. Can't deicide if its my CAT for sure or not. It runs just fine if I don't let it warm up in this cold weather, but if I let it warm up for like 20 minutes then drive it, it'll drop to a low rough idle, almost un-driveable. (It did this to me today while on my way to work on the highway. It's not fun driving 35 in a 50mph zone)

 

[Ak907Girl]

oh, and BTW, I dont have a tacomoter. I dont have a clue what it's idling at.

 

[bert296]

my check engine light goes on an off randomly i havent checked the codes yet. tonight i was coming up to a stop light hit the clutch and it stalled completely and had a very hard time starting back up when it finally started it ran and drove just like it was and didnt have another problem. ill check the mass air flow tomorrow is there a way to clean it or just buy a new one?

 

[Brandon Nootenboom]

I know there are mass airflow cleaning kits out there, it's definitely worth a shot. I'm gonna pick one up when I have the money and see if it helps my problem. And when my idle control valve was bad my truck did the exact same thing. Just die then start rough but run totally fine. Maybe your idle control is bad too?

 

[LIMA BEAN]

I know there are mass airflow cleaning kits out there, it's definitely worth a shot. I'm gonna pick one up when I have the money and see if it helps my problem. And when my idle control valve was bad my truck did the exact same thing. Just die then start rough but run totally fine. Maybe your idle control is bad too?

You dont need a KIT to clean your MAF just get this.

It has good directions on the can, just make darn sure you dont touch the filament or you will kill it.

 

[bert296]

I know there are mass airflow cleaning kits out there, it's definitely worth a shot. I'm gonna pick one up when I have the money and see if it helps my problem. And when my idle control valve was bad my truck did the exact same thing. Just die then start rough but run totally fine. Maybe your idle control is bad too?

i changed the idle control valve the other day is there another part to it this happened the next day. im hoping tomorrow is a little warmer (-3 below heat wave here in maine today) so i can try and clean the mass air flow anything else you can think of? you have been alot of help thanks

 

[bert296]

should i unhook the battery so the computer resets its self to reconizes the new iac???

 

[Ak907Girl]

If it's randomly stalling. TIMING BELT.

 

[snake]

Not necessarily... If it had low power AND didn't idle maybe the timing could have jumped a tooth. Most belts break rather than slip when they fail but that's not to say it couldn't. If not the IAC a vacuum leak is the next probability for erratic idle.

 

[Brandon Nootenboom]

I un-hooked my battery to let the computer re-set after putting a new O2 sensor in, that way I would know if it came back on there's something else wrong. It came on and it was my mass airflow sensor. The timing belt is a possibility but it wasn't that for either my 91 or 97 4.0. I cleaned my mass airflow sensor and my idle problem went away finally, or at least for 2 days afterwords... Now my center driveline bearing is kaput so I haven't been driving it. Only thing I an think of is another sensor maybe going out

 

[adsm08]

I'd def reset the computer. If it is still iffy at idle post back here and I'll give you the idle re-learn procedure. It's long and a pain, so I don't want to type it out without having the obvious stuff done first.