LB7 FPRV Shim Mod ???
- Thread starter wdino73
- Start date
I was unaware that you can Shim an LB7.... you have to plug it off similar to a race valve the specs are posted around here PM Trentnell he did it on his LB7
I believe it can be shimmed , I welded mine shut though
Simon and a few others have done the same , either welded it shut or plugged it , Very few times have i ever heard of an LB7 having issue's with it though .
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I was reading on another site an they showed using 2 washer, I didn't know that I would ask,
http://www.dieselbombers.com/lb7-bombs-aftermarket/34726-lb7-fprv-shim-mod.html
http://www.dieselbombers.com/lb7-bombs-aftermarket/34726-lb7-fprv-shim-mod.html
Just take the Fuel Rail Pressure Regulator housing with you to the hardware store and find a washer that will fit. I was thinking it is a 6mm outside diameter washer but i am probably wrong. Yes, the LB7 can be shimmed and makes a huge difference if you've popped it off a few times.
Simon once called it a pop once valve.
Simon once called it a pop once valve.
okay i have a fast ? so im pretty sure my fpr is going out it was replaced at chevy like 50k ago or so im thinking of puting a lbz fpr in. do you have to shim what?....
sorry for the dumb ? still learning
sorry for the dumb ? still learning
No. However, there are modified ones available on the market. Pat may have some or Wicked diesel. The FPR you are referring to is on the cp3 correct.
There is not more than one unless you have dual cp3's. The relief valve they are speaking of is in the fuel junction block behind the cp3. I just tapped and plugged mine. Used a set screw and some red loctite.
There are two different parts with same acronymn.
Fprv = fuel pressure relief valve
Fprv = fuel pressure regulator valve.
The first one is what this thread is about. The second one is the one on the cp3 and is what lb7kid is asking about.
Think I got that right.
As to op question. No idea. More rare issue on lb7 & when is a problem or to prevent it, I thought must just plugged it.
Later
Fprv = fuel pressure relief valve
Fprv = fuel pressure regulator valve.
The first one is what this thread is about. The second one is the one on the cp3 and is what lb7kid is asking about.
Think I got that right.
As to op question. No idea. More rare issue on lb7 & when is a problem or to prevent it, I thought must just plugged it.
Later
As they have said, one is a mechanical " Limit " valve = FPRV a Mitch said #1.
The other is an electrical duty valve ' of sorts ' which controls the actual fuel into the cp3 plungers and ultimately to the injectors. As Mitch said #2.
Plugging number 1 or shimming number 1 is up to what is chosen. Personally, I wouldn't want to risk a chance running my well used components with out a fail safe means to controlling rail pressure. So, I just shimmed mine instead of plugging it. Although, I may have very well shimmed mine more than what will ever pop off. Shimming my not fix a leaky valve
The other is an electrical duty valve ' of sorts ' which controls the actual fuel into the cp3 plungers and ultimately to the injectors. As Mitch said #2.
Plugging number 1 or shimming number 1 is up to what is chosen. Personally, I wouldn't want to risk a chance running my well used components with out a fail safe means to controlling rail pressure. So, I just shimmed mine instead of plugging it. Although, I may have very well shimmed mine more than what will ever pop off.
Shimming my not fix a leaky valve
while i had mine apart, i thought i would shim it. i started puting my engine together yesterday.
What size plug do you need. I thought about taking mine off and finding a Allen plug to go on the inside to replace the stock Allen plug that has the center open.
any care to show how they did this? i might try making mine stay shut it to see if it helps my falling rail issues...
bottle test is much easier than trying to shim it to see if thats your problem ya know