Stumbling at idle/acceleration - IAC?

[j602]

I've had this problem get worse over the past couple weeks. When I come to a stop, the engine will idle rough and stumble a little through acceleration. It just sounds kind of like the engine is missing. Once I get up to speed it usually smoothes out, and sometimes the idle will smooth out on it's own after a while. From what I've read, it sounds like it's the IAC crapping out on me, but if it's the IAC, will it still stumble some through acceleration? Thanks in advance for the help.

 

[410Fortune]

Not likely, clean the MAS and intake and the IAC all at once, then reset the battery.

how long since its had plugs and a fuel filter?

I assume the CEL is not on?

 

[j602]

No CEL. Cleaned MAS when I put the KKM on about a week ago; plugs and wires were changed about 5 or 6 months ago. When I bought the truck about 15 months ago, the fuel filter and lines looked brand new, so I assume it was installed recently. I'll try cleaning the IAC, and if that doesn't work changing out the plugs.

 

[j602]

OK, just got done cleaning the IAC. Still runs like crap. I'm starting to think I have a bad plug or something.

 

[satsuperman]

drop 40 for a new MAS

my 94 x did the same thing as did my 94 ranger (same motors in both). stop beating yourself up over this one and just run to a parts store and get a new MAS (mass airflow sensor). They are about 40 bucks and it is a lot easier to just replace it than fight the good fight on trying to pull the old one and clean it. They are the type of part that we all wish they could have done without, but we arent that lucky. Ive seen a bug's wing kill one, that is how sensitive they are. Look at them like a pregnant woman.....the smallest thing can set them off and cause a world of hurt. Ive had 3 of them go out in various ranger and x's.....first it starts as very intermittent, then gets worse. first you usually notice a little hesitation at a stop light that gradually becomes an occasional bucking while you are on the highway. eventually it is all the time and very agrivating. Swap it and be happy.

 

[TPLYNCH]

I'd start with the Fuel Pressure Regulator. If yours is still original, it's well past time it crapped out.

 

[j602]

Well for some reason, it almost completely stopped today. I think I might have gotten some water in the gas filler tube when I was spraying the undercarriage the other day after a play in the mud. So, I think some water got in the gas, causing the rough idle/stumbling.

 

[j602]

I just thought I'd bump this thread for anyone who might be having the same problem and give a definite answer as to what it was. Turns out it WAS the IAC (which was my original thought). So if you're engine's stumbling at idle and acceleration up to about 2k RPM, check your IAC.

 

[gss]

Hey, thanks for the follow-up. It is always the little things that drive us buggy. Bought a DPFE today to replace mine, I 've been fighting CEL for several months now, light comes and goes. Cleaned the MAF last week. Probably will clean the IAC while I'm messing with it.
I was going to pull the codes today and the light went off again before I got to the parts store to borrow their ODII.