I am the owner of a 1996 Toyota 4runner. Recently, when I bring the vehicle to a complete stop, the entire SUV shudders, almost lunges, forward. At times it feels like the brakes are trying to re-engage.
Could really use some pointers on this issue.
Please give us a better description.
If the shuddering takes place before the vehicle comes to a complete stop, then I would suggest having the ABS checked (assuming that the vehicle is so equipped), and the power brake booster is another component that might bear checking.
If the shuddering takes place after the vehicle comes to a complete stop, then you can rule out the brakes and instead should focus on an engine/driveability problem which could involve components such as the Mass Air Flow Sensor (MAF) or the Idle Air Control (IAC), or…
Is the Check Engine Light illuminated when this problem takes place?
I’d second VDC and say that my own starting points would be a brake booster (leak in booster, line, or check valve problem) and IAC valve (sticky/sluggish). If the brake booster has an issue you should be able make the engine do funny things by just sitting at idle and simulating the kind of brake pressure being applied when the truck does this. If you can’t get anything out of that I’d be cleaning the IAC and throttle body.
Thank you for the quick responses. Yes, vehicle is equipped with ABS; also a manual transmission. This is happening immediately after truck is brought to a complete stop. On the one Mississippi of a three Mississippi count at a stop sign.
Let me ask this, would I find the MAF under the vehicle on its way to the muffler? Also, where would I find the IAC? Thirdly, how greatly do either one of these impact the truck from a complete stop? i.e sluggishness/ shuddering…
MAF and IAC are in the intake stream, not the exhaust stream, and either can cause stalling, stumbling, or other such problems like you are experiencing. They are responsible for air metering into the engine, and errors on their part can cause these symptoms. To positively identify their location and how to check/replace them, a Haynes or Chilton repair manual will help you tremendously. They are available specifically for your vehicle at your nearest auto parts store for around $25 and can teach you a lot about your car. Highly recommended if you are going to attempt repairs or diagnostics yourself.
How does the vehicle lunge forward at a stop with a manual transmission? Do you hold down the clutch with the shifter in first at a stop or do you shift to neutral and leave the clutch out? If you leave it in gear and it does this, you could have a hydraulic clutch or pressure plate issue.
check ur brake fluid if its low look for leaks inspect booster for wetness and calipers make sure nothing is seized… also check for vaccuume leaks (seriously)
Is this a braking issue or an engine performance issue? What is causing the problem? The brakes or the engine?