LB7: surge!

[REDHOSS02]

So I took my truck in to have the cp3 replaced with a LMM pump because mine wouldn't hold pressure. So i picked it up and after I got to the red light I noticed at idle it was surging. I thought maybe it just needed time to bleed out air or get used to having pressure again, I don't know. I have been through one tank of fuel and still the same problem....any ideas on what could have been missed during the installation procedure?

 

[03 D-max]

If it has an LMM fpr then you will have to change the tuning to get rid of the surge i had the same thing when i went to an lbz fpr

 

[DIESELMAFIAPER.LB7]

If it has an LMM fpr then you will have to change the tuning to get rid of the surge i had the same thing when i went to an lbz fpr

x2 on that make sure you either have your lb7 (which i doubt) fpr or an lmm also does it seem to idel really high rail pressure or does it sound normal except for the surge? its it just surge probably have a bad lb7 fpr

 

[REDHOSS02]

I replaced the fpr about 20k miles ago and when I had the cp3 out I shimmed the fpr with 3 m4 washers but it is still the lb7 fpr. I talked to a couple guys and they said the LMM pump is the same as the LB7. Was there something I should have done other than pull the old pump and install the new one?

 

[03 D-max]

the fpr we are talking about is the fuel pressure regulator which is located on the cp3, the fpr you shim is the fuel pressure relief valve 2 different parts

 

[REDHOSS02]

hahaha! nice to know NOW! There is no way I am pulling all that shit off to get to that fpr. Ignorance man it kills me. So I can tune it to equal everything out?

 

[stacks04]

tuning will only help if its the lmm reg. the lb7 regulator should not require tuning. i doubt its the lb7 though. most cp3 come with a reg in place. i guess a call to the mechanic would confirm this.

 

[REDHOSS02]

I know for a fact the LMM cp3 pump has the LMM regulator on it. It was pulled right out of an LMM and put in my LB7.

 

[SSchmi5519]

This can be changed in EFI live.

Theres a table for the regulator reference. If your is still set to the lb7 specs, it will surge.

Just copy the LMM values into your tune.

Look for table "B1010"

 

[Mike_S]

This can be changed in EFI live.

Theres a table for the regulator reference. If your is still set to the lb7 specs, it will surge.

Just copy the LMM values into your tune.

Look for table "B1010"

Bingo! If you are picky, you may have a little more tweaking to do to it to get it "just right"...but that should get you really close.

 

[03 D-max]

now that you have an lmm fpr you can raise your max psi's :cool2:

 

[SSchmi5519]

now that you have an lmm fpr you can raise your max psi's :cool2:

AND, it will do something.

 

[REDHOSS02]

now that you have an lmm fpr you can raise your max psi's :cool2:

Haha! Gotta love efi live even though I barely know how to plug in the cables! Thanks to ol phil and danno they do all the technical stuff haha! Thanks guys:thumb:

 

[REDHOSS02]

But wait are you saying that I can get more psi out of the lmm fpr than the lb7

 

[maxaholic]

The lmm cp3 will put out more pressure.

 

[DIESELMAFIAPER.LB7]

yes but when you have a lbz-lmm fpr on a lb7 an its not tuned for it, it will run 21ksi at idle cuase the tables are ass backwards he never complained bout it sounding like its wraped up all the time at idle?