88 FourRunner 22re 5 spd. Drove home from work fine today. Ran up to auto parts place to by parts for my other car. Started up and the engine begins to surge while driving. Slow down to turn the corner it died. It started right back up but the surging is still there. Ran it while idling and RPMs jumps up and down about 500 RPM’s. Any ideas on what might be causing the symptom?

 

are you brakes applied while it does this?

 

No the brake is not and my foot is not on the petal when this happens

 

any check engine codes? or lights? You might have codes without having a light.

 

I'll have to check for codes in the morning. Hopefully they will tell me whats wrong. Thanks I forgot about checking the codes .This is my first toyota since giving up a 20 year a jeep habit. Having much better time in the yota!

 

Ran the codes this afternoon. Came back as TPS. Turns out it was barely plugged in guess the last time I took off road it out must have jarred loose. Plugged it back in runs like a champ. Figure it wouldn’t hurt to tune it up. New plugs, cap rotor and wires. Cleaned out the throttle body timing check runs better than before.

Thanks for your help on this one

 

Checked your plug wires lately? I had some surging/missing on the highway which was really frustrating me.

I checked all the vacuum lines from the throttle body to the EGR/Vacuum modulator (I think that's what it's called) and found some worn vacuum lines. I replaced these lines and while it didn't fix the surging/missing problem, my cold idle speed kicks down at the right time and the exhaust doesn't smell as rich now. Gas mileage/engine power has improved noticably as well.

In further search of a repair for my problem I started poking around the spark plug wires/coil wire and gave myself a few good zaps. This started to narrow it down, so I waited for it to get dark and started the engine then had a peek under the hood...it looked like a lightning storm under there..every single wire was arcing all over the place!

I just replaced the wire set a few minutes ago (in -14 degree weather no less), took it for a little spin and didn't notice any surging or missing. Tommorow I'll take it on my longer commute and see what happens, but I think I've solved my problem. You should go have a look under the hood now that it's dark and see if you can see any arcing plug wires, maybe check to see if one has come loose while you were checking the oil dipstick or something as well.