1994 4Runner stuttering/hesitating on acceleration
Apr 7, 2017 | 02:57 PM
#1
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1994 4Runner stuttering/hesitating on acceleration
1994 4Runner V6 230k miles manual
Ok so for a while now I have noticed that my 4Runner seems to stutter/hesitate when acclerating at high speeds. Usually in 5th gear on the highway, more often going up a slight hill. It makes me feel like I need to downshift, but that doesn't make any difference. I'm usually at 3000 rpms or so, so I'm not lugging the engine or in the wrong gear. It does not do this at idle, and I haven't really noticed the issue at lower speeds. We thought maybe we got bad gas but this has been intermittently been happening for a few months now. We replaced the spark plugs and wires maybe 10k miles ago.... but I'm going to check them again. What else should I check?
Ok so for a while now I have noticed that my 4Runner seems to stutter/hesitate when acclerating at high speeds. Usually in 5th gear on the highway, more often going up a slight hill. It makes me feel like I need to downshift, but that doesn't make any difference. I'm usually at 3000 rpms or so, so I'm not lugging the engine or in the wrong gear. It does not do this at idle, and I haven't really noticed the issue at lower speeds. We thought maybe we got bad gas but this has been intermittently been happening for a few months now. We replaced the spark plugs and wires maybe 10k miles ago.... but I'm going to check them again. What else should I check?
May 30, 2017 | 08:42 AM
#4
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Joined: Jul 2012
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From: Northern Colorado
Along with the other suggestions, check the TPS and make sure it doesn't have a dead spot somewhere in the upper part of its range. Easiest way to check is to back probe the connector, pin 3 (solid yellow wire closest to the green wire), with ignition on and engine not running. Have someone press the accelerator slowly (or advance the throttle by hand on the throttle body) while you watch the voltage on a multimeter. You should see it smoothly rise from 0 to 5 volts. Any hiccups or dropouts means the TPS is dirty or bad, and you'll get erratic operation when you hit that spot as you press the accelerator while driving.
You can also disconnect the TPS wiring (ignition off) and check resistance directly on the TPS, between pin 1(brown-black wire) and pin 3(yellow wire). Absolute resistance isn't as critical as smooth increase as you open the throttle. Again, any dead spots or sudden changes are bad.
You can also disconnect the TPS wiring (ignition off) and check resistance directly on the TPS, between pin 1(brown-black wire) and pin 3(yellow wire). Absolute resistance isn't as critical as smooth increase as you open the throttle. Again, any dead spots or sudden changes are bad.
