3406b missing allen screws from pump??

They are still around you gotta know where to look

 

Where are you at that doesn't have any b model cat mechanics?

 

I'm in south east Va. I guess not mess with it is wrong wording I told him my problem and he couldn't advise me on what to do besides check my filter, fuel lines, turbo and check for boost leaks

 

Thank you guys for your help got it back together. The new diaphragm does hold suction and shuts off now lol

 

So the truck still runs the same only about 13-15lbs of boost even with the new diaphragm

 

Torque rise and fuel have to match. No 2 ways about it. What is the fuel pressure idle and full load. What is tge restriction after the filter on the frame but before the lift pump. Also have you checked the timing that causes low boost. Have you checked the plungers in the pump. That's just a start at what causes low boost and power. Again it's pretty crucial for the torque rise and fuel rate to match

 

So a little update this weekend I did my regular maintenance changed oil, fuel filters, greased the truck ect. So I picked up my freight Monday morning about 100 miles into the load im I start climbing a hill drop a gear and its like someone hit a switch in on the motor. I'm pushing 26lbs of boost. Now before this with my new diaphragm I was getting 16-17 tops. Now it boosts to 26 and will creep up to 30lbs on a long pull with about 800-825 on the exhaust temps. Now I haven't changed the screws like you guys had told me yet. So I'm just wonder why the truck is running so well now?? If it was the filters I thought it would have been like this right away not a hundred miles into my load? Just wondering what would cause such a change its like I have double the power now which makes it much nice to drive... Sucks pulling hills 35mph in a 70 mph zone...same hills pulling 50-55 now. Thanks for your help

 

So 10 miles into my driving today and I'm back to low power, like someone just flipped a switch....any ideas of what is going on would be much appreciated

 

Sounds like your not getting full rack travel. Matching the screws inside the pump is crucial as Wore out stated. My first thought was you had a charged air leak, creating low boost numbers. But you said the boost magically came up while driving. Now, as long as your not fibbing a little on those numbers it would indicate to me and others on here that the pump was not fully opening. Then when it did finally open up you got that raise in power and boost.

 

No the numbers were correct.according to my gauge. So you don't think it could be a week transfer pump or fuel line collasping? Just wondering why I would get fuel rack travel for 2 days then go back to not traveling all the way when I didn't do anything different? Thanks for your help and advice