LBZ: New cp3,still p0087!?! [Archive] - Duramax Diesels Forum

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Devon
07-19-2011, 05:20 PM
Ok after doing the cp3, still only getting 19,650 at wot..what else possibly could it be? Injector rates are all good.


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JMK777
07-19-2011, 05:30 PM
prv?

02bigstrokin
07-19-2011, 05:34 PM
take that race valve out and throw it in the trash can. get a stock valve and shim it.

Devon
07-19-2011, 05:41 PM
What makes you think it is the race plug? Just curious


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paint94979
07-19-2011, 07:22 PM
I have had a race valve for over 25,000 miles and have not yet had an issue with it... but it is def. worth ruling out.

ripmf666
07-19-2011, 08:11 PM
Just bottle test the truck first.

Chevy1925
07-19-2011, 08:15 PM
Just bottle test the truck first.

x2 if no fuel found, return rates on each injector needs to be tested

02bigstrokin
07-20-2011, 03:17 AM
What makes you think it is the race plug? Just curious


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Some people don't have any problems with them like nick said but I've had 2 llys that were falling off rail just like yours, we put a stock shimmed valva in and it fixed it. Jmo

Devon
07-20-2011, 04:16 AM
Ok I may try that.anywhere I can get a stock valve for cheap? Also,what else could I check besides that and injector return rates? My airdog is pulling fuel so that is working right.. Maybe install a sump on the tank?


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adrenaholc1
07-20-2011, 04:22 AM
Damn man that sucks. X3 bottle test. What regulator do you put on new cp3? We both need to check lift pump pressure also.

coker6303
07-20-2011, 04:42 AM
I've got a buddy with a lmm and the same mods as me except he has the ppe race valve and ported fittings. His truck constantly throws the P0087 low fuel press code. May have to try the stock valve with a shim to see if it helps.

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Devon
07-20-2011, 06:46 AM
Yea this is really starting to piss me off, on top of that I have a boost leak coming from the intake bridge I belive. I don't think its the injectors because on the smaller tunes it holds good rail.


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juddski88
07-20-2011, 08:06 AM
I guess the next step is putting a fuel pressure gauge on and seeing what its at at WOT

x MadMAX DIESEL
07-20-2011, 08:09 AM
Can't see on my phone, but whose tuning are you running?

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Devon
07-20-2011, 08:38 AM
Robs as of right now, also have dustins too..robs race tune desires 27,500 from what the edge cts reads Only getting 18-20k though


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x MadMAX DIESEL
07-20-2011, 08:51 AM
So more than likely it is mechanical.. I was thinking it could be something in the tune... do the bottle test it is easy.

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Texas Chevy
07-20-2011, 09:07 AM
I had a race valve in and the truck ran fine then one day at highway speeds truck fell on it's face and threw codes limped to 55 mph and I had to stop to get it to move again. Put the rce valve out and the truck runs fine I only get the code on the race tune now.

HogAssWild
07-20-2011, 09:20 AM
Im on stock valve and have never had this code?

I run on a 600 horse tune everyday

Devon
07-20-2011, 10:11 AM
Could my injectors be shitty? Even if all the balance rates where ok? Also would I benefit from a hellmann sump?


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Chevy1925
07-20-2011, 10:20 AM
x2 if no fuel found, return rates on each injector needs to be tested

Could my injectors be shitty? Even if all the balance rates where ok? Also would I benefit from a hellmann sump?


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See above, and yes they could be bad. a hellman sump isnt a bad idea but not required GO DO A BOTTLE TEST FIRST!!!!!

Devon
07-20-2011, 11:30 AM
Going to do a bottle test once I'm off work,not doubting anyone telling me to do a bottle test but how could it leak past the race plug? Isn't that the purpose of the plug,to block off all fuel from returning to tank and prevent any leaks?


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Chevy1925
07-20-2011, 12:15 PM
Going to do a bottle test once I'm off work,not doubting anyone telling me to do a bottle test but how could it leak past the race plug? Isn't that the purpose of the plug,to block off all fuel from returning to tank and prevent any leaks?


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All PPE's FPRV is a stock FPRV shimmed for higher pressures. this doesnt mean it will hold higher pressures. Sometimes they hold and sometimes they dont. Unless you actually have a solid plug in that threaded opening or welded it shut, its possible to have the FPRV pop open and drop fuel pressure. IF you have a new CP3 and balance rates on the injectors look good, then this is the next logical/easy thing to check in the sequence of diagnosis.

x MadMAX DIESEL
07-20-2011, 01:48 PM
When they leak with a race valve they seep past the threads. Its happened before..

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juddski88
07-20-2011, 01:49 PM
All PPE's FPRV is a stock FPRV shimmed for higher pressures. this doesnt mean it will hold higher pressures. Sometimes they hold and sometimes they dont. Unless you actually have a solid plug in that threaded opening or welded it shut, its possible to have the FPRV pop open and drop fuel pressure. IF you have a new CP3 and balance rates on the injectors look good, then this is the next logical/easy thing to check in the sequence of diagnosis.

that's not true, PPE's race plug is solid. I have one. it could be a couple of things, and I would look at them in this order: check for kinks or restrictions in the bypass line that was made to delete factory filter, if none are found, measure low pressure feed PSI, if it doesn't drop much at WOT, then do a bottle test.

x MadMAX DIESEL
07-20-2011, 01:51 PM
He has a race valve not there shim kit. What you have is a gold plated plug like a bolt, nothing like a spring or anything in it. I've heard from someone else that he's had customers with the hold flaking off and hurting injectors. Another story... just bottle test it its real easy, just be sure to block off the return side too or you'll have a big ol mess. Kinda common sense I guess but I forgot to once

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juddski88
07-20-2011, 02:45 PM
He has a race valve not there shim kit. What you have is a gold plated plug like a bolt, nothing like a spring or anything in it. I've heard from someone else that he's had customers with the hold flaking off and hurting injectors. Another story... just bottle test it its real easy, just be sure to block off the return side too or you'll have a big ol mess. Kinda common sense I guess but I forgot to once

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What??

He has a race valve, exactly like mine, no shims, no confusion that I am aware of....

There is no gold-plating on my race valve.

And by bottle testing, I mean I am going to take the return line that goes to the cooler off, and see how much fuel I get in, say, 10 seconds. It wont be too messy.

Chevy1925
07-20-2011, 02:57 PM
that's not true, PPE's race plug is solid. I have one. it could be a couple of things, and I would look at them in this order: check for kinks or restrictions in the bypass line that was made to delete factory filter, if none are found, measure low pressure feed PSI, if it doesn't drop much at WOT, then do a bottle test.

ah yes, i forgot about that. i kept thinkin his was shimmed with the PPE shim kit. my bad :D

x MadMAX DIESEL
07-20-2011, 03:51 PM
What??

He has a race valve, exactly like mine, no shims, no confusion that I am aware of....

There is no gold-plating on my race valve.

And by bottle testing, I mean I am going to take the return line that goes to the cooler off, and see how much fuel I get in, say, 10 seconds. It wont be too messy.

What? How is anything I wrote any different than what you said? You just typed/read faster. I was saying that maybe the other guy was mistaken and thought he had ppes shin kit. I know what the race valve is, its like a bolt/plug. Maybe the new ones don't have plating anymore but they used to afaik. Also go take that return " u shaped" line off and cruise around for abit and hammer down... you WILL have fuel pour out on your test drive if it is not plugged on the return side. Idk what your talking about 10 seconds wise? Maybe using dvt to bring up rail pressure for the bottle test?? I do mine with real world driving... doesn't the dvt only bring rail psi to 160? You probably won't get much of a spike using the dvt function.

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juddski88
07-20-2011, 08:49 PM
What? How is anything I wrote any different than what you said? You just typed/read faster. I was saying that maybe the other guy was mistaken and thought he had ppes shin kit. I know what the race valve is, its like a bolt/plug. Maybe the new ones don't have plating anymore but they used to afaik. Also go take that return " u shaped" line off and cruise around for abit and hammer down... you WILL have fuel pour out on your test drive if it is not plugged on the return side. Idk what your talking about 10 seconds wise? Maybe using dvt to bring up rail pressure for the bottle test?? I do mine with real world driving... doesn't the dvt only bring rail psi to 160? You probably won't get much of a spike using the dvt function.

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i saw afterwards that you were just answering the both of us but not separately.

A bottle test is done to compare an acceptable rate of return to the GM spec. the gm spec is given in Ml/sec or L/sec or whatever. so in order to get any good data from a bottle test, you must be consistent and know how long you tested for.

I have never done a bottle test at full rail at idle but I can't imagine it being very fun.

x MadMAX DIESEL
07-20-2011, 11:15 PM
Sorry if I came across a dick.. didn't mean to if I did. But Fwiw you shouldnt be returning any fuel with a race valve, or any shimmed valve.. if you are, tighten the race plug, or add another washer to the shin kit

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juddski88
07-21-2011, 05:21 AM
The factory valve only pops after 24k psi or thereabouts, so a stock valve shouldn't allow any return fuel? The injectors and the cp3 return through a separate line, so it is very possibly to return fuel with a race valve

dmaxfireman
07-21-2011, 05:36 AM
I'm pretty sure that the return on the rail is not affected by the cp3 return at least on an lbz.

you take the hose off the back of the drivers side rail and plug it, then put a longer hose on the rail and put the other end into a bottle, you should get no fuel out of it if you have a race valve and minimal fuel with a shimmed valve after a WOT run

ripmf666
07-21-2011, 06:25 AM
I'm pretty sure that the return on the rail is not affected by the cp3 return at least on an lbz.

The cp3 and all the injectors return on the same fuel line. Just giving the guy a pic off what it looks like with everything off lol.

http://i133.photobucket.com/albums/q80/ripmf666/LBZTakeout069.jpg

dmaxfireman
07-21-2011, 06:36 AM
i understand that henry, but if he puts a plug in the hose coming off the rail and then puts a longer hose into a bottle off the rail only he will know if the race valve is doing its job correct?

ripmf666
07-21-2011, 07:13 AM
i understand that henry, but if he puts a plug in the hose coming off the rail and then puts a longer hose into a bottle off the rail only he will know if the race valve is doing its job correct?

Yes plug the top side of the return of the little horse shoe hose or the return fuel from the cp3 and other injectors will make a mess. I just worded it wrong while posting the pic of the general area of the fuel lines. And after pluging the little line run line off rail to bottle and tape it inside the bottle well and take for a ride and see if it has fuel or raise rail pressure with efi live or tech2.

juddski88
07-21-2011, 07:40 AM
Raising rail with dvt function would be the way I was going to go about it...but...we didn't get past the boost leak last night. My own fault. Fixed it but as I was putting the last bolt on the lower tab of the egr pipe, the horn off the Y-bridge cracked at the flange

McRat
07-21-2011, 07:44 AM
Thoughts:

P1093 is the normal code you see with PRV problems on LLY's.

Race valves don't always seat as well as OEM valves do. I don't recommend them anymore.

There is a tutorial for the Shim Mod and the Bottle Test IIRC (this is like 6-7 years old?).

GM now sells the PRV separately. They used to just sell the whole rail.

Like above, 3' hose to the nipple on the driver's side rail (rear) then to a bottle, U-shaped hose should be plugged (low pressure).

A bad race valve leaks at it's seat, so it leaks under normal engine output (stock tune). However a bad factory PRV only leaks at a pressure spike. To test OEM valve, put in big tune, hammer it, then chop the throttle suddenly at full output.

juddski88
07-21-2011, 08:10 AM
Raising rail with dvt function would be the way I was going to go about it...but...we didn't get past the boost leak last night. My own fault. Fixed it but as I was putting the last bolt on the lower tab of the egr pipe, the horn off the Y-bridge cracked at the flange

Devon
07-21-2011, 08:52 AM
Yea, what a night lol.I'll do the bottle test, if that comes up ok then I'm going to get ahold of airdog and see if I can get a new pump.


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x MadMAX DIESEL
07-21-2011, 09:44 AM
Yea, what a night lol.I'll do the bottle test, if that comes up ok then I'm going to get ahold of airdog and see if I can get a new pump.


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Have you watched the lift pump pressure drop to nothing?

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juddski88
07-21-2011, 09:54 AM
He doesn't have a gauge on it bud

x MadMAX DIESEL
07-21-2011, 11:29 AM
I'd get a 10 dollar pressure gauge on it forsure. another cheap test. I've had lift pumps not pump fuel, even though the pump motor was running. So you never really know until you check it out.

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Devon
07-21-2011, 04:37 PM
I am just going to buy the indicator light from dmaxstore,then I'll know once my airdog drops below 5 psi or whatever it is.also be purchasing a stock shimmed valve


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adrenaholc1
07-21-2011, 07:53 PM
Unless I over read it somewhere I didn't see where you said which fuel pressure regulator you used on your new cp3. Did it come with a new one on it?

JoshH
07-21-2011, 08:10 PM
Just to clarify, doing a return rate test and a bottle test are two different things. A bottle test just checks to see if fuel is leaking past the fuel pressure relief valve. A return rate test usually involves checking the return rate of the injectors. On LBZ and LLY motors, GM specifies that each injector should be tested individually. On the LB7 they have you run the CP3 return into a separate container and then run both injector returns into another container and measure the amount of fuel returned for a given amount of run time.

x MadMAX DIESEL
08-22-2011, 01:14 PM
Anybody know eactly how to do a return rate test on an lbz. I read some people test them cranking on llys, but there is no way to crank without starting on lbzs...

Burn Down
08-22-2011, 01:34 PM
I didn't get much of any fuel just cranking. I let it start and idle for 20 seconds each time. 1 and 4 are toast...
http://i976.photobucket.com/albums/ae245/hotrodalbert75/IMG_0192.jpg
http://i976.photobucket.com/albums/ae245/hotrodalbert75/IMG_0191.jpg

x MadMAX DIESEL
08-22-2011, 01:37 PM
Alright good thing you don't need to just crank it... I don't think there is a way to crank without start on lbz. Where would one buy those measuring cups, I don't think theres any science class stores around here lol

Burn Down
08-22-2011, 01:51 PM
I bought a used Kent Moore kit off of ebay. Simon found some Horse syringes at a feed store.... I think you will still need the brass fuel line adapters, or be real careful pulling the rubber lines off of the plastic nipples.

mtl_dmax
12-03-2011, 06:25 AM
I didn't get much of any fuel just cranking. I let it start and idle for 20 seconds each time. 1 and 4 are toast...




That's pretty telling for sure, thanks for the pics.

I got a set of (4) 100ml graduated cylinders off ebay (maybe $5 each). Instead of getting the Kent Moore injector nipples, I just took the right side injector return line (cheapest) and separated all the hoses from the injector T's. Then I plugged one side of each T (used a small screw to plug the line on one side) and hooked a rubber line from each (make sure all the lines are the same length) on the other side, put them into each of the graduated cylinders and idled the engine for 30 seconds exactly (that way I could compare readings from both sides). I ended up buying 2 return lines since I was concerned about cracking on the plastic T's, but if you wanted to go as cheap as possible you can just replace the right side return line.

mtl_dmax
12-03-2011, 06:37 AM
GM now sells the PRV separately. They used to just sell the whole rail.



Pat, do you have a part number for the stock FPRV because I thought they still only sold them with the rail?

It would be handy to be able to get a new LBZ valve for my LLY.

mtl_dmax
12-13-2011, 10:39 AM
Pat, do you have a part number for the stock FPRV because I thought they still only sold them with the rail?

It would be handy to be able to get a new LBZ valve for my LLY.


Nevermind I found it:

98090186 - SENSOR F/INJN FUEL RL FUEL PRESS, (PART OF 3)


Looks like Huckstorf still has them alot cheaper direct from Bosch though.

mtl_dmax
01-28-2012, 10:24 AM
Nevermind I found it:

98090186 - SENSOR F/INJN FUEL RL FUEL PRESS, (PART OF 3)


Looks like Huckstorf still has them alot cheaper direct from Bosch though.





Not sure what I was thinking, but that's not the FPRV part number above (it's the fuel rail sensor P/N).

This is the correct FPRV P/N for an LLY: 97358556

This is the correct FPRV P/N for an LBZ & LMM: 97371618

Oregon Fuel Injection also carries them separately if yours can't be shimmed anymore.