WHY IS MY 07 TRYING TO STALL WHEN BRAKING?

2007 Chevrolet Colorado

Tiny

LiLRascal

February, 21, 2012 AT 5:20 AM

This began with starting. Would crank then try to die but catch back up. Replaced plugs and that seemed to help. Then it started again but seems to be worse when braking. Braking to make a turn the engine will try to die then pick back up and will do this repeatedly until you get off the brakes and apply the accelerator again. Runs smooth down the road and doesn't miss at idle. Problems seem to be only at first start up and when braking. I am also having to replace ABS wheel speed sensors on the front as they were damaged when replacing rotors. Could this have anything to do with the problem. I can't remember if this started about the same time. I know the stumbling at the starting was before the wheel sensor problem but the braking problem may have started about the same time. Wondering if the circumstances could be related?
Thanks!
Joe

FOUND 24447 RELATED QUESTIONS

Cj Stalling When Idling

33 ANSWERS
50 IMAGES

Stalling Out

43 ANSWERS
52 IMAGES

10 Answers

Tiny

KHLow2008

February, 21, 2012 AT 12:31 PM

The ABS sensors should not be related to the poor idling.

If the engine idles correctly when the brakes are not applied, then you most probably has a leak in the brake vacuum system and this is causing a vacuum leak which can cause erratic idling.

Tiny

LiLRascal

February, 22, 2012 AT 2:41 PM

I replaced and repaired the ABS wheel speed sensors but the ABS fault light is still on. The vehicle will stumble at cold start then smooth out but will stumble again when you pull it in gear and nearly die but not quite. After that the stumbling only occurs when you are breaking for a stop or turn but as yet has not actually died. It is getting worse, however, and am expecting it to start dying anytime. Not very familiar with this vehicle. Where would you look for the vacuum leak? KHLow2008's response makes a lot of sense as I have experienced this with the older models which I am more familiar with.

Tiny

KHLow2008

February, 22, 2012 AT 3:52 PM

The additional information indicates you have a fault with the idling system and I would suggest starting with cleaning the idle control system which includes the throttle body and IAC.

For the ABS fault, what is the trouble code?

Tiny

LiLRascal

February, 22, 2012 AT 4:16 PM

Will try that and thanks! As for the fault code I am not sure as yet. Haven't had it checked. I'm old school and my old ways of retrieving code doesn't seem to work with this vehicle so have been taking to a mechanic to diagnose. Can I determine code with out scanner? I am guessing it is the wiring as it was broke on the driver side and I have tried to splice it. Had to replace passenger side with new one so I would think that one would not be the problem? Maybe good but can't get lights to go out. Tried to remove battery cable but that didn't work or the light came on immediately with starting.

Tiny

KHLow2008

February, 22, 2012 AT 4:33 PM

Without the fault code, you would be working blindly and replacing things that are good on a trial and error basis.

Tiny

LiLRascal

February, 22, 2012 AT 4:42 PM

Yes, I understand that. Will soon be going to my mechanic friend and let him check the codes. Thanks Again!

Tiny

LiLRascal

March, 8, 2012 AT 3:51 AM

Ok guys, When this brake trouble originally started I pulled the ABS1 and ABS2 fuses hoping to kill the system and fault lights. I would have been completely happy with that. However, that didn't work. I have went back and repaired the system but the lights stayed on. Had it checked by a mechanic friend and the components checked ok and the brakes were working and found code 201. Finally determining the code was electrical problem with abs fuse #16 I checked that out and found all was well. But I noticed the 2 missing fuses and remembered what I had done. Replaced the fuses, started up, the lights went out, yea! Wrong. When starting down the road and applied the brakes considerable vibration in the brake pedal, scrapping-grinding sounds, a pumping vibration sound like an electric fuel pump, then all noise quit and the lights came back on. Brakes still work. It was dark and haven't checked fuses yet but my question is should I taken it through a reset process of some type? Any thoughts? Thanks!

Tiny

KHLow2008

March, 8, 2012 AT 1:04 PM

The pedal pulsation indicates the ABS is working at that instance.

Since the ABS indicator light is back again, check the trouble code again and let me know what it is. You can try resetting the code and retest.

Tiny

LiLRascal

March, 9, 2012 AT 5:25 AM

I haven't had a chance to recheck the code, however, when we went out this morning and started up the light went out again. When we started down the road and hit the brake all the ruckus started again. Pushed the pedal a little harder the light came back on and all the racket etc. Stopped. We stopped for something and when we started back up again same thing, light out, racket, light off. Craziest thing I ever came across. Will check codes at first opportunity and report. Thanks!

Tiny

KHLow2008

March, 9, 2012 AT 12:28 PM

When the light comes on, the ABS system has been disabled, therefore nothing to alarm you.

I believe you have a fault with the ABS master pump ( modulator itself).

Please login or register to post a reply.

Code Read Retrieval/Clear Chevrolet Camaro
Code Read Retrieval/Clear Mercedes Benz
How to gather codes Ford Explorer
Code Read Retrieval/Clear Honda Civic
Code Read Retrieval/Clear - Dodge Stratus
Read Codes Like a Pro