Have been running lean for a month or so. Even bone stock the truck had an a/f ratio of about 13.0 at WOT. Also, EGT's were high. Two trips to two different dealers found no problems.

I noticed that the fuel pressure wasn't as responsive to boost as before.

Changed the fuel filter, and decided to drop the gas tank to inspect the fuel lines since I have read here that some of you had problems with some of the lines. As long as the tank was down, I went ahead and upgraded the pumps to the PSP dual 255's.

Well, the fuel filter seemed slightly clogged. Was hard to blow air through. Truck only has 3000 miles.

Here is the interesting part. Sure enough, the longer of the two fuel lines that connect the pump to the "Y" fitting had a 3/4" split in the line. The split had worked its way through the line, because it would lose air pressure when blowing through the line with the other end plugged.

Now, the EGT's are lower and fuel pressure is much more responsive to boost. But I believe that I am still a little lean. Will have a/f measured in a few days and my chip reflashed to compensate if necessary.

If it weren't for the fuel pressure guage and EGT guage, I would have been clueless. The high EGT readings were what first tipped me off. Hopefully this may help some of you.
Chris S.

 

Thanks for the info. What were the egt readings and then the normal lower egt readings?

 

Before fuel filter replacement and fuel pump upgrade,
#3 max EGT @ 80-100mph WOT = 1600 deg. F
#5 max EGT @ 80-100mph WOT = 1500 deg. F

After new filter and pumps,
Readings about 100 deg. F cooler.

Still lean. Will have a a/f session this week and a chip reflash thereafter.