LB7: FPR Install Fun!!!

[Krazykid]

update , did you get it working ?

Nope, Thanks for checking back. where is the pressure relief you mentioned before? I have the mouth piece out and was going to put in old one back in, but it seems that the little T25 screws got tighter. So before I get really screwed by stripping the screw heads I might just put it all back together with the moded FPR and give it another go?

 

[TrentNell]

There is no releif just crack loose the high pressure line coming out of the cp3 or any of the HP lines just to release the pressure . This happend to mine and pressure was so high it wouldn't alow start up , cracked the line , relieved the pressure it started right up ! Not saying this will work but worth a shot .

 

[Krazykid]

There is no releif just crack loose the high pressure line coming out of the cp3 or any of the HP lines just to release the pressure . This happend to mine and pressure was so high it wouldn't alow start up , cracked the line , relieved the pressure it started right up ! Not saying this will work but worth a shot .

Ok I just got it all back together. (Haven't Cracked the HP line yet.) Please advise on the attached Log file. BTW Larry Jewal did some modification to a few tables to maybe help.

 

[Krazykid]

Sorry that the Log file did not attached properly. Here it is.

 

[TrentNell]

i see no change , i would have to say its stuck . sorry man , did you ever try the pressure relief ?

 

[JoshH]

On an LB7 does desired fuel pressure default to max if the regulator isn't plugged in? I was gonna suggest checking your connection to make sure it's plugged in good, but I see your desired is still at 5k psi. I think desired goes to max on an LBZ if they aren't plugged in, but I'm not sure on the LB7.

 

[Krazykid]

On an LB7 does desired fuel pressure default to max if the regulator isn't plugged in? I was gonna suggest checking your connection to make sure it's plugged in good, but I see your desired is still at 5k psi. I think desired goes to max on an LBZ if they aren't plugged in, but I'm not sure on the LB7.

Josh,

I have double checked and now triple checked the plug(s). I have kind of hijacked this tread cause I am working on a LLY, sorrry for the confusion.

 

[JoshH]

I knew it was your truck we were discussing. I just for some reason wrote LB7. I'm gonna have to go with Trent on this one and say your regulator is stuck.

 

[Krazykid]

I knew it was your truck we were discussing. I just for some reason wrote LB7. I'm gonna have to go with Trent on this one and say your regulator is stuck.

I hope to relieve the High Pressure fuel line tonight to see if it will unstick. Another thing I notice when flashing a tune update is there is a hummmm coming from FPR? It seems like when you first start the truck is runs fine and then at about 20 secs into running things get worse. Any ideas?

 

[TrentNell]

I hope to relieve the High Pressure fuel line tonight to see if it will unstick. Another thing I notice when flashing a tune update is there is a hummmm coming from FPR? It seems like when you first start the truck is runs fine and then at about 20 secs into running things get worse. Any ideas?

Modd your other regulator and install it

, if it is running good for 20 secounds then it maxes out , kinda sounds like you may have bought a bad reg , but its so hard to tell with out being there .

just some info of how the regulator works , the "current" actually pulls or pushes the valve shut not sure which , thats why normally when you unplug it the pressure maxes out because there is no "current" to hold it shut , so a bad reg can max out also even when plugged in , and one that is stuck means that the resistance is too great for the availible "current" to pull/push it closed . what is the pressure when the key is on and the engine is not running ?

that is also why in the tuning you request more amperage at idle to pull/push it shut harder to fix the idling issue ( if there is one) .

 

[Krazykid]

Modd your other regulator and install it

, if it is running good for 20 secounds then it maxes out , kinda sounds like you may have bought a bad reg , but its so hard to tell with out being there .

just some info of how the regulator works , the "current" actually pulls or pushes the valve shut not sure which , thats why normally when you unplug it the pressure maxes out because there is no "current" to hold it shut , so a bad reg can max out also even when plugged in , and one that is stuck means that the resistance is too great for the availible "current" to pull/push it closed . what is the pressure when the key is on and the engine is not running ?

that is also why in the tuning you request more amperage at idle to pull/push it shut harder to fix the idling issue ( if there is one) .

Trent thanks for the explation starting to make sense to me now. Heres the update as of about an hour ago. Did what you suggested by releiving pressure. After that mmy DA forgot to clear codes and started the truck after about 20 secs of idleing the truck shut off. Pumped the fuel pump and started again, after about 1 minute or so the truck started to purrrrr again. I was like great, lets see if it's fix shut the truck off and started again codes are back and hard knocking is back as well.

The old FPR I think was going back by surging at around 2000rpm. thus I was on the hunt for a NEW modified FPR and got this!

 

[sweetdiesel]

On an LB7 does desired fuel pressure default to max if the regulator isn't plugged in? I was gonna suggest checking your connection to make sure it's plugged in good, but I see your desired is still at 5k psi. I think desired goes to max on an LBZ if they aren't plugged in, but I'm not sure on the LB7.

Des will = 5kish Actual will = 160ish If the regulator is unplugged

 

[sweetdiesel]

Des will = 5kish Actual will = 160ish If the regulator is unplugged

LLY is the same

X3 on the stuck regulator IMO it is best to log rail current and ofcouse act and des rail press

Mod your old regulator and slap it in

 

[Krazykid]

LLY is the same

X3 on the stuck regulator IMO it is best to log rail current and ofcouse act and des rail press

Mod your old regulator and slap it in

What are the chance of me having the the same issues with the old "Modified" by me problems? I was hopeing to get rid of the surgeing issue with a new FPR (modified). So will the surgeing still be there if I modify the old FPR and reinstall it?

 

[sweetdiesel]

What are the chance of me having the the same issues with the old "Modified" by me problems? I was hopeing to get rid of the surgeing issue with a new FPR (modified). So will the surgeing still be there if I modify the old FPR and reinstall it?

That is why you need to log the regulator current Just need to tune it out. Also Lift pumps will effect reg current,Depending on how your pump(s) are set up can effect.

I cant say what your regulator will do, as they are all different on other trucks.

Perhaps its not the regulator and it is the harness?

 

[TheBac]

If you're saying that Lift pumps can affect how the regulator works, then two questions pop into my head:

1) What pressure does a FASS run at, and can I easily hook up a gauge to find out the current pressure??

2) Do modded regulators require lower feed pressure to work correctly? If so, what is that pressure?

 

[Krazykid]

That is why you need to log the regulator current Just need to tune it out. Also Lift pumps will effect reg current,Depending on how your pump(s) are set up can effect.

I cant say what your regulator will do, as they are all different on other trucks.

Perhaps its not the regulator and it is the harness?

Ok, Im so tahnkful for the information you guys are providing. What "PID" do i need to select to log such information. I'm in the process of install the original FPR. Back to Square one! I was going to ask the question of can I unplug the FPR and use a Voltmeter to read the current manually? If so what am I looking for?

 

[sweetdiesel]

If you're saying that Lift pumps can affect how the regulator works, then two questions pop into my head:

1) What pressure does a FASS run at, and can I easily hook up a gauge to find out the current pressure?? The Fass useally runs around 10 psi
Ya lots of people run lift pump gauges,I use a electric gauge and can log it with EFI if I want

2) Do modded regulators require lower feed pressure to work correctly? If so, what is that pressure?

Whatever your desired current is shoot for that in idle areas

Ok, Im so tahnkful for the information you guys are providing. What "PID" do i need to select to log such information. I'm in the process of install the original FPR. Back to Square one! I was going to ask the question of can I unplug the FPR and use a Voltmeter to read the current manually? If so what am I looking for?

You can use a volt meter but your asking the wrong guy HOW

Attached is a pid file - unzipp and copy it into EFI/ pid files

 

[Krazykid]

So the old FPR is back in the truck with original tune reflashed. Truck is about to idleing like it should. Now to touch base on with the modified FPR. This is just the "sleeve" in the tip of the FPR right? So I "Should" be able to remove it from one and place it in the old FPR and all "Should" be fine, correct? Or should I just be ont he hunt for a new FPR?

 

[sweetdiesel]

So the old FPR is back in the truck with original tune reflashed. Truck is about to idleing like it should. Now to touch base on with the modified FPR. This is just the "sleeve" in the tip of the FPR right? So I "Should" be able to remove it from one and place it in the old FPR and all "Should" be fine, correct? Or should I just be ont he hunt for a new FPR?

Yes it is just the sleeve on the inside is the new and old the same style reg? As in lly lb7 lb7?