rough idle '94 pickup

Hi there...sorry to post another question so soon...but just happen to
have 2 annoying problems right now..certainly thanks in advance for you reading this...

anyway, it's a 22RE 2WD '94 pickup.

it really chugs at idle, and on the verge of stalling. not real smooth.

runs fine at higher RPM's..but when I step off the accelerator, the engine RPM's dive hard into a grumbling/stall sound and then resumes to a rough idle.

I have looked carefully at the vacuum hoses, and they seem fine.

I will plan on checking the spark plug gaps (but I did them not too long ago).

Could it be something like the O2 sensor ? Any other thoughts ?
:1zhelp:

Have you checked for any codes?

Have you checked for any codes?

does the '94 pickup have diags like that ?
it didn't jump out at me in my little Haynes manual.

I played around with the vacuum hoses, and thought there was a leak, but
couldn't pin it down. I think the "hiss" I hear is probably normal.
All the hoses look solid, none are off.

I am more concerned with the weird behavior when I take my foot off the gas, the RPM's drop to almost a stall, then pick up again to a normal idle speed.

I've been having the same problem w/my 86 4x4.stalling when I stop for a light,but only after dring for a while 7or8 miles.10yrs. I had this truck and fixed nearly everything on it, when I can't or haven't the time my "ace" echanic works on it.very long story but try to make it short.First checked and/or replaced all vac.lines.still no-go.replaced fuel-pump relay(was getting hot) still no-go,but! as soon as I replace or exchange the relay with another it runs again,but then quits.mechanic says fuel pump is shorting out causing the relay to open causing the truck to stall,that didn't sound to right in the first place but I replaced the pump with a new one,now I drive about 30 miles and think well that was it..not.still stalled out.yet I exchanged the relay with a cold one I keep as a spare,starts right up.So I don't have an answer to your problem this may save you the expence of a fuel pump.I will post the fix as soon as I find it.Don't give up.
Good luck,
Budd

thanks for the post ...

I still have the problem, but was not able to fix it.

very interesting what you found out.

in my case it doesnt stall, but close to it. once I take my foot off the accel, it engine slows down to a "shudder" and then resumes normal idle speed. it works better when the AC is running, since the idle is higher.

it's seems like the fuel delivery is not right during the transition from driving to idle. it must have something to do with the way the fuel supply system works. I'd have to know more about it to fix this problem...
:banghead:

I would almost put money on it being a crack in the plastic air intake tube. The relay clicks on and off to try to keep it running. If you wiggle on the intake tube while it's running and that is where the problem is it should make itself obvious. Good luck.

Use duct tape to patch it, she'll run good as new.

I still have not found the problem. Now, even changing out the relay isn't working. It just dies.7or8 miles down the road it quits! If it starts it will run lousy(can't give it any gas or it will stall.) I'm running out of things to replace and I just know it's 'gonna be something real stupid and easy.Well...what is it? Later on or tomorrow it will start and run good.Until 7or8 miles pass by.(I know...don't drive that far).HELP ME.please

well sorry to say but my gf '93 w/22re was doing the same, it turned out to be a cracked head in cyl #1 and then she blew out the head gasket and yeah....ok but back to it, you need to start with your fuel delivery, get a inline pressure guage, cost you maybe $30 w/fittings, check it out, next go to your charcole return tank under your intake, shake it around see if its coming apart inside and blowing air insted of a solid blow, its like its intermit., not good if its not solid air flow on revving your motor, then go to the junk yard and fine a new mass air flow sensor! that baby will make your truck run like shit if its starting to die. Let me know what happens!!!