waltrobak

I have an 01 GT 4.6L 2V that is not running right and I can not figure it out. If it is warm out it will start with no problem, the colder it gets the harder it is to start and if it gets near zero it will not start. That is a problem here in upstate NY. Also, when it is running and you stop and shut it off it will not start, it acts like it is flooding out. Last, when it is running if I use reg unleaded gas it will knock and ping pretty bad, if I use super it will still do it but not nearly as bad. I am running totally stock with the exception of the BBK shorty headers and fuel system.

I have replaced the Crank, Cam, MAF, IAT and the two front O2 sensors, the PCV valve, Plugs, all 8 Injectors and the throttle position sensor. I am running a returnless fuel system with a new Aeromotive Pressure Regulator and a new TRE 255LPH fuel pump. This seems to be working just fine holding the pressure at 39PSI constant while running at high rpm's or at idle. I have been told that the computer has checked out just fine and all sensors are in the perfect range, so the engine should be running like stock. I had a custom tune that I had a problem with so I purchased a new custom tune from JMS Chip & Performance. It runs much better now then it did before, but I am still having all the issues I mentioned above.

I am at a loss at this point, any suggestions?? Thanks

JC316

What about the fuel filter? You can get good PSI, but poor flow. Otherwise, I say it's the tune.

Thatsweetstang

I live in Cali so I don't ever come across really cold temp no start conditions. I would also check the coolant temp sensor, and I'm pretty much out of ideas man :/ sorry.

waltrobak

It has brand new fuel lines and a new fuel filter. we checked the pump and it had no trouble pumping 110PSI and the injectors held at that pressure so they are not leaking, also the flow from the pump is great. This is the second person that I am dealing with for a custom tune, the first one did not work at all and this one I am guessing still has some issues. Thanks

art02gt

is the battery in good condition?

TXMach

Have you tried returning to stock tune?

waltrobak

The battery is brand new. I can not return it to stock because the motor and computer were taken out of the car and is installed in a Jeep Wrangler. I have tried it already, but because the pats are not removed from the stock program locks down the computer when I try to start it. I wish there was a way to use the stock program and just remove the pats. I would almost guarantee that would solve my problem.

WJL

Just out of curiosity how did you wire the pcm in to a jeep? there are a lot of sensors that need to be connected and working before it would ever start.

just saying

waltrobak

It has been a while since I have been on. I had a harness made up specifically for this motor and computer. All of the sensors and two front O2 sensors are connected to the computer and I had to get a custom tune to get around the PATS issue. The engine runs perfect once started, it is the getting started in the cold weather that is a big issue. For some reason the engine seems to be getting way too much fuel at start up and instantly floods out.