View Full Version : cold start

12-21-2005, 10:13 AM
I am having problems starting my car when it is below about 45 degrees. What it seems to be is the computer (PCM?ECM?) on the passenger side kick panel.....because when I heat it up it will start no problem. Also, I can not set the anti-theft system because it will go off. Now, since I have a s'charger and there is a chip plugged into the computer.......does this have any affect on my problems? What are some things that could cause the problems I'm having? I already replaced the computer thinking that would be the solution. If the chip is causing the problem can it be re-programmed or tuned? Or will I have to buy a new chip from Paxton? I would appreciate any help possible.


01-07-2006, 10:25 AM
The anti-theft issue may have something to do with the tune or the chip. That may be corrected by having the ECU re-flashed. I would check the FAQ on the Pasxton website or send them an e-mail of what you placed in the forum. It is possible that the cold star issue may also be related since the anti-theft system disables the ignition to prevent the car from starting by compression starts (coasting the vehicle and poping the clutch if the starter was disabled). If you had start problems when hot, I would almost guess there is too much air supplied to the intake. The IAC may be a bit gummed up which may cause start issues as well as a stuck PCV valve or loose vacuum line some where). The IAC acts like an automatic choke on cold starts. I would inspect the throttle plate for any accumulation of tar (if it does not close all the way due to the build up, the IAC will not be able to choke off the air properly). However, the start issue may be related to the anti-theft problem.

IF you have to heat up the ECU to get it to start, it is possible that there is a connection issue with the wire harness, or a damage component on the added chip. In some cases, if the surface mount parts or through hole parts on the PC board do not have a good solder connection, when cold the joint becomes an impedance that could cause random issues. Also, what may help would be to disconnect the chip and ECU and reconnect the parts back together just to rule out connection issues. If that does not correct the start issue, I would contact Paxton for a replacement of the Chip assembly. There may be a QC issue with it (open via, poor solder joints, or damaged trace or cracked component on the board which was missed by their QA inspection. More than likely what you described is related to the Paxton chip. To rule out the Paxton component, try removing it and see if the anti-theft system works or the car starts without any issues. Shut it off as soon as it starts. I am assuming the Paxton chip is a plug in PC board that sit between the wire harness and ECU. Since you already replaced the ECU, more than likely it is in the Paxton chip assembly. I would see if you can send that back to them for replacement (you may not have to buy another one if it is under a limited warranty), I would at least contact them first before buying a replacement.

01-10-2006, 09:57 AM
Thanks for the helpful advice and info! I removed the chip and it started right up on a cold morning.....so now I know the problem.