2.4 wants to stall when accelerating from complete stop

widbyj · 09-03-2011, 09:50 PM

I've had similar problems with my S/C setup also. 1st time found the vaccum/boost sensor had popped out, easy find and fix. 2nd time it ended up being a failing TPS sensor. There is a re-calibrate procedure, which worked for a while but I ended up replacing it via Autozone. Simple swap-out was worth it, the shaft had cracked in the original one. When the ECU can't read the throttle position properly it lets the vaccum signal tell it what it needs to do about the fuel injection which is inaccurate and laggy. Good luck!

knowledge8069 · 09-03-2011, 11:06 PM

This is a very good recommendation, I will pick up a new TPS tomorrow and install it. For $40 it is definitely worth a try. If I am swapping a new one in, does it need calibration?

Also what is the vacuum/boost sensor? Is this a MAP sensor?

AleroB888 · 09-04-2011, 12:57 AM

Quote:

Originally Posted by knowledge8069

This is a very good recommendation, I will pick up a new TPS tomorrow and install it. For $40 it is definitely worth a try. If I am swapping a new one in, does it need calibration?

Also what is the vacuum/boost sensor? Is this a MAP sensor?

I've had a couple TPSs fail also, and vacuum-related problems as well. I can relate to the problem you're having, got a minor version of it right now in fact. But mine is a V6, though. I believe MMGT1 recommended a crank position sensor replacement on mine, but I haven't found time to do that yet.

What happens if you power brake it to about 1200 rpm, and then floor it? Does it still hesitate/stall out then?

Bypass actuator working OK?

knowledge8069 · 09-04-2011, 07:46 PM

Installed a new TPS today, did not fix the problem. =(

It doesn't matter if I have the brake on or not, the engine will hesitate. It does it in park, drive and neutral also.

I checked the S/C bypass valve system. The actuator/solenoid is working fine. It's not closing the bypass too early, only under a good amount of throttle. I don't think it's choking from too much air through the S/C early on.

I messed with it some more today. As I said before, it idles fine but hesitates between 900 and 1300 RPMs. Once it is below or above this range, everything works normally without any hesitation.

I suppose I will need to have someone use a scanner to see what's going on during these hesitations. Seems to me it might be a problem with air or fuel. Maybe the ECU is going crazy.