So today it's been raining cats and dogs here in Utah. I decide to go get some breakfast, go out to start the truck and it always starts right up and the same with this morning. The usual high idle when its cold and then it idled down and its running like crap!! Spit and sputter and running ruff! I've noticed this before when I go through automatic car washes. So could it be the mass air flow detecting too much moisture in the air? When I get on it, its running just fine and when it goes back to an idle and starting out in 1st gear it runs like crap until I get into higher rpm. Anyone else have this problem?

 

Check the distributor cap for cracks, splits in plug wires or boots where water could cause a short to ground issue.

 

Yea check your ignition components replace if old or questionable for good measure also check the intake piping around the throttle body and the Maf area for leaks (unmeasured air ) . Every now in then you can clean your Maf with either Maf cleaner or gently with q-tips specially if you run a kn filter or any oil soaked filter

 

Good to know thanks!

 

Deff check the plug wires and dizzy cap. 85ish celicas had a rubber boot over the dizzy cap. Might help keep ya dry. I would think the coil end of the coil wire is getting damp. It's pretty close to the edge of the hood. Also, check inside the cap for any corrosion. If you have any crud scrape it with a knife. Same inside where the plug wire connects. If you don't have brass inserts, try to find them when you replace it. The older years are nearly impossible to find brass, only aluminum.

A high output coil wouldn't hurt either. Like an msd blaster 2 or accel supercoil. The msd must be mounted vertical if you want a long life from it. I've started to prefer the accel after toasting a few blasters. 3 years or more on the one in my 78 tho. Not totally vertical either. My dodges eat them up tho.

 

Don't mean to thread jack but I pretty much have the same problem as but opposite on cold start my truck idles at around 500-600 rpm and when I'm running it idles around 700-750 rpm and when driving coming to a stop it idles at about 1000-1200 rpm but I'm on carb to me it's like my carb is not returning right not to sure..

 

Don't know if you already have a manual but if not here you go. It's the Toyota repair manual.

1993 Toyota Pickup Service Manual

 

Aftermarket carb . Throttle return spring to weak
Fast idle out of adjustment stock carb

 

After market carb bot to sure if return springs weak sometimes slow idle and fast idle

 

If its a weber there return springs are tiny . I use a variety pack of universal throttle return springs and maid my own so I get a full return of the throttle plates every time .. I used to floor it sometimes and have to deal with a sticky high idle after the spring it solved it .....grab your weber linkage while its running and rotate it opposite if the idle drops some ya need a good spring