Contour Enthusiasts Group Archives Forums Modifications General Mods TH fix leads to poor cold start driveability?

I have a 99 SE V6 MTX with the TH fix and have noticed some poor driveability on cold starts. Yes, the throttle hang is fixed but on cold starts the car responds poorly to part-throttle tip in/tip out. It feels like there is significant lag between gas pedal position and powertrain response. These symptoms clear up when the car warms up.

Could this be related to a cold start ECU algorithm? Is some air bled by the TB through the bypass at cold start for some reason? Anyone else have this problem?

-Kurt

nope. Try changing plugs and wires first before you blame a proven mod.
Also, might want to try fuel filter etc. cheap stuff really.

BZZZZZZZZZZT, wrong answer. Cold start and cold driveability stumbles are two symtoms of the TH fix that means your hole is to small for your particular vehicle. The hole size/s listed on this site are only a starting point to work from and may not work in all climates on vehicles with different mods.

Go up one 64th at a time in your hole size until you get good cold starts/drieability.

I had the same problems before I did the TH fix. hasnt really been super cold around here lately, so I havent really felt it. I just assumed it was a dirty TB. Which, any day now I want to clean. (71k without cleaning=dirty TB)

CYA
Mike

Brad Noon has the right answer. Mikes advice to make sure that the throttle body is clean is also correct.

Even under the best of conditions, the TH cure is somewhat of a compromise. I sometimes have a minute or so of cold drivability problems when the weather is cold. We don't get that much cold weather here in Southern California, but on the few days in the year that it gets close to freezing, it helps to not use too many electrical items for a block or two.

Some use two different TH plugs, one for winter with a slightly larger hole, and one for summer. It is not like it is hard to change.

Brad, thanks for setting the record straight.

-Kurt