GT/CS Guy

Ok. Here's the deal. I've got a 2009 GT/CS with a 4.6. I've got a 2.3L Whipple blower with a bunch of other mods. After getting it tuned (even with the stock tune that came from Ford with the blower kit), when the car has been sitting outside in 40 degree or less temperature, once the engine has cooled down, it takes 15-20 times of trying to start it before it finally starts and stays running. A few times, it will blow white, rich fuel vapor out the back of the car.

However, if I leave the car in my climate controlled garage, it can be there for days on end without being touched and fire right up and run perfectly on the first turn of the key. My problem only happens when the car is out in the cold. It is NOT giving me issues when the motor is at room temperature even when it's been idle for days.

This seems to me like an intake temperature sensor issue. Only problem is, I CAN'T FIND IT on my setup. I would like to replace it and see what difference it makes, but it's no where to be found. I had the blower kit installed professionally at the dealership, so I am taking the car back to them to ask them where they relocated it when they installed the kit.

Any advice or comments? Anything would be appreciated! Thanks.

GT/CS Guy

Duh. The IAT is part of the MAF. I brain farted that one. That's not the issue. I went digging into the installation instructions for the blower kit and it tells you to disconnect the engine coolant temp sensor, relocate the harness behind the passenger head, and then hook it back up. Thinking it might be unplugged (even though I don't have any codes currently), I went hunting for it and found that it WAS in fact hooked up (PIC 1)

But in doing so, I found this little guy (PIC 2/3) and I have no clue what it's supposed to hook to. There's nothing back there. I would REALLY appreciate it if one of you fellow 4.6 peeps could help me out and see if yours is hooked up and if so, where it runs to. Thanks!!

Lime GT

Looks like an O2 sensor connector to me. Are any or all 4 of yours removed?

GT/CS Guy

Well. It looks to be a timing issue. I took the car to the dyno shop for live monitoring/data logging. They brought up the table that shows the timing at different temperatures. From 0-40 it's -34, or something like that. From 40-60, it's -6. From 60 and up, it's -34. Only problem is, they couldn't duplicate my issue because after letting the car sit outside all day, the motor ended up being below 40 degrees when they started it, so it acted and started normally. It only acts up between 40 and 60 degrees, which just happens to be the range of higher (dealing with negative numbers here) timing.

So tomorrow, they are going to monitor the motor temp and when it hits 50 degrees, they are going to try and start it to see if they can duplicate my problem. If they do, they are going to adjust the timing for those temperature ranges and it SHOULD fix my problem. Stay tuned.

GT/CS Guy

FIXED!!

It all started with the Ford tune that came on the tuner with the blower kit. The timing for the cold start parameters (temperature wise) for 40-60 degrees was way out of whack. Freezing to 40 and 60 to 200 were all the same settings, but 40-60 were all messed up. That's why it starts perfectly in the garage, but not when it's outside. My local Dyno shop was able to duplicate the cold start problem today and after 3 times of trying to get it to start, they went in and fixed the timing parameters for the 40-60 degree settings. After that, it fired right up!

Anyway, that was the fix. Thanks for everyone's input and time!!