I'm trying to gather some information regarding injection pump tweaking (P7100).

I would like to know what is the usual/acceptable temperature variation between cylinders. I'm measuring at the exhaust manifold with an infrared temp gauge and from coolest to hottest cylinder have a difference of about 10 degrees F. Most are about 5 degrees different. Is this normal or should they be closer? I realize that there can be very subtle differences from the barrels/plungers and DV's as well as injectors. Trying to get some base line info and haven't seen this one discussed. Any help is appreciated.

Paul

 

first off, the only experience i have is from this website and playing with my truck, an overvalved '02. but...

the reason we put the thermocouple in the rear manifold runner is because the rear cylinders run hotter (# 4, 5, and 6). this is probably because of the coolant passages, it enters the front of the motor and flows to the back. so because of that reason you would probably notice a difference in cylinder temps. i am not sure if they run hotter under load or at all times, i would assume all times because of the coolant deal.

again, i am not experienced with this. just my .02

Pat

 

I messed around with my 93 350 as you have and dont remember the ##, but there was more than 10-15 degrees difference. I would imagine injector performance will affect temps.