LB7 Help

bigmackmiller

Active member
Nov 30, 2008
1,046
2
38
Kokomo, IN
Need some help deciding what to do with my new to me LB7. Picked it up in OCT last year and shortly after I got it noticed it start to surge at idle. I have been running a double dose of Stanadyne performance additive, and just ran an injection cleaning procedure two days ago. All but that bastard #4 showing respectable as far as balance rates are concerned. Have not did a return test but did have danville check out the truck. They are indicating it would be best to replace CP3 and injectors when the time comes. I'm not sure if my CP3 is really bad as pressure seems to be adequate and inline with desired (see attached), all though it does jump on either side of desired PSI. Could that surging be from the bad inj. or from a failing FPR?

Truck has AD150, Cat Filter Adapter with fresh filters, S&B intake, ported intake horn, boost valve, Edge CTS, and Danville tunes. Also did notice im getting no PSI readout on my edge from the airdog, has proper EAS adapter. Can hear pump running so not sure if it is truely not making PSI or if I have a bad sensor
 
Last edited:

bigmackmiller

Active member
Nov 30, 2008
1,046
2
38
Kokomo, IN
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Awenta

Active member
Sep 28, 2014
4,090
2
38
CT
No need for a mechanical gauge. Unhook the hose and turn the key on. It will be pretty obvious if it's running or not.

What is your main fuel rate?

Also, how does it run? What do you need help deciding on. That's a bouncy rail. Sticky fpr usually only lopes around idle unless it's really bad. I'd lean towards a cp3.

I'd be more concerned about injector number 2 than 4.


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bigmackmiller

Active member
Nov 30, 2008
1,046
2
38
Kokomo, IN
Will have to check on fuel rate, and will double check on #2, runs good other than the slight surge at idle and while cruising, main question was is my cp3 in good shape, and is the pressure bouncing above and below desired caused from a FPR that is going out?