My truck vs the cooler outside temps

[jdheff1982]

Ok, so a few weeks I installed an E-Performer 750 to replace the sh*tty 600 that was on there. That was when the temps were still in the 80's to 90's. Since then, the tmeps have cooled off and mthe truck is not liking it.

First start in the morning usually takes about 5 pumps just ot get it running. After that, it is a struggle trying to keep it between 1.5 and 2.0 K RPMS. If I lett off just a hair, the motor takes a nose dive to the 0 to 500 RPM range and getting it back up is erradic.

I know the hose from the brake boost is good and the dizzy line is good. Not so sure about the tranny line. The PO used clear tubing up to a certain point before it switches over to plair rubber hose. I haven't had any shifting problems, so I haven't replaced it.

Any adjustments I have made to the carb include the following,
1.) Increase accel pump stroke length to bottom hole. Truck was hesitating upon take off from stand still. The hesitation has decreased, it is still there and start up is more difficult than before. It used to take maybe 1 or 2 pumps at top hole, now it takes more on bottom hole.

2.) Idle mixture screws have mean adjusted, but not accurately. I was able to get on side to increase engine rpm, but the other side wouldn't do anything. I plan to rent a vacuum gauge this weekend and properly adjust it.

3.) I have idle set at 1000 rpms. When it is warm out, the rpms will drop to 700 or 800 rpms when in gear. Now that it is cooler out, the rpms are barely above 500. Even after driving the truck for 10 minutes from work at a near constant speed of 40 MPH, it was trying to die as I was slowing down to park at home.

One thing I have noticed is that idle and cruise performance seems erradic. One day, it might drive fine. Another day, it could be gasping for air at idle. Cruise is ok, but the motor misfires alot. Not sure if the wires are jumping or what. The spark plugs are only 2 months old.

The only constant that I have seen with the motor is only when my foot is in it. If I drive it around say above 2500 RPMS, the motor loves it and performs well.

Other than checking the trans vacuum line, I am unsure as to what else I can do to get lower rpm driveability. And please don't say that the carb is too big. These problems have slowly been creaping up as the temps have gotten cooler.

Any ideas and help would be appreciative. Thanks in advance.