how to tell if regulator is bad

[Porno Joe]

heres my issue- truck smokes at idle and more than a slight haze off idle. clears up nicely once you are moving. I just put new injectors in it, balance rates are in spec so i do not suspect injectors are the issue

Truck has 40 over injectors and dual lbz cp3s

last night i took a log of desired vs actual rail pressure. according to my laptop, at cold idle( truck sitting for approximately 4-5 hours) truck was commanding 3500 psi and actual was 8700 psi. I unplugged my air dog, no change to rail pressure (though i may not have left it unplugged long enough).

this am on the way to work, i couldnt log the actual vs desired, but i watched the actual rail pressure on my aeroforce scan gauge. I noticed that a few times as i would pull to a stop sign, the rail would start decreasing, to say around 5k as i slowed down, and then when the truck came to a stop, it would jump back up to like 6-7k.

the 2nd cp3 was new in oct, maybe 5k miles on it. the one in the valley is original as far as i know with 193k.

Right now im suspecting regulator in the valley, but i dont know? could it be something with the dual pump controller?

looking for ideas on what it might be, or what tests I might be able to do/ logs to look at tonight to get this fixed

 

[dirty_max]

I don't have much experience with the dual pumps, but if you unplug your airdog and leave it unplugged for a little bit will it lope? mine was sort of doing the same thing, and that is what I found. but I only have one pump as well.

 

[Porno Joe]

Ok I did some logging tonight.

I logged my base tune with the lift pump off and on. And I logged my dsp-2 position with lift pump on. Lift pump is set to 10 psi.

All 3 times start up the truck and desired vs actual is dead on.
Once with the lift pump running my actual rail psi at idle was 5000. Desired was 4300.
Driving around the truck is fine. I scanned the logs and foot on the gas the rail is always near desired.

Here is the only issue I see- several times (2 or 3) as I was slowing down to a stop sign rail would drop. Desired around 43-4400. Actual would drop then rise again, once to 6700. Once I stepped on the go pedal they even back out. Next time I slowed to a stop they are back in line.

Could one of my regulators be sticking?
Could the haze I'm seeing out my tail pipe be from too low rail pressure at idle for 40 overs?

 

[dieseladdiction23]

I wonder if a malfunctioning dual cp3 controller could cause that?

 

[McRat]

The regulator works backwards.

If it is dead, the CP3 goes full blast. Voltage keeps the pressure down. Unplug a regulator and try to drive it.

 

[McRat]

I wonder if a malfunctioning dual cp3 controller could cause that?

Why Yes. Yes it can. I had that happen once.

 

[Porno Joe]

Is there anyway to test the dual pump controller?

 

[Porno Joe]

I checked all connections on my pumps. All looked good. Unplugged my cp3s and rail pegs like i expected. Plug back in and back to normal.

I'm lost where to look now

 

[McRat]

Is there anyway to test the dual pump controller?

The only way I found out was to swap it out. PPE might know how to test.

 

[Porno Joe]

Ok just put 800 miles on the truck over 3 days of driving.

Once during the trip (this morning) I start the truck up letting it warm up a bit and get it. Rail psi is at like 8,000. Threw a code for high rail. Soon as I pop it in drive it would come down.

Drove over to fill up and soon as its back in park it goes up. Kept doing it till I got on the highway. Drove like 2 hours stopped and its fine.

Could it be maybe a bad/poor ground on my dual cp3 controller?

 

[jmaz268]

The bad ones I've seen (one on mine and another on a buddies)....

log the fpr % and look for dead spots, both of ours would only go to about 35-40% and just stop or create an invalid %

 

[Porno Joe]

Ok update here. Still battling this.

I had one new LBZ regulator. So first I tried swapping it into my second CP3. No change.

So put old one back in. Last night I change the regulator in the valley. Driving today- no god damn change.

The only thing it could be now is the dual pump controller. At least that's what it seems to me. Maybe a poor connection to the controller?

Driving around everything works great. Actual vs desired dead on. Just sometimes when at idle actual will climb much higher than rail. Driving this am of the 15-20 times the truck was sitting at idle, prolly 3-4 did the rail psi climb

 

[Hot COCOAL]

Isnt it common to raise the rail pressure at idle when running bigger injectors to help maintain fuel atomization or something like that, so there is less haze at idle?

 

[Aaron@LDS]

What brand injectors do you have in there? I believe if your injectors are larger than they are tuned for it will haze at idle. It's possible that your rail pressure is correct, but still hazing because the injectors are slightly larger than you have them tuned for.

EDIT: I posted the same as ^^^^ I agree that they are probably not atomizing the fuel correctly.

 

[Porno Joe]

What brand injectors do you have in there? I believe if your injectors are larger than they are tuned for it will haze at idle. It's possible that your rail pressure is correct, but still hazing because the injectors are slightly larger than you have them tuned for.

EDIT: I posted the same as ^^^^ I agree that they are probably not atomizing the fuel correctly.

You guys missed the point here. The tune is commanding a certain psi and the truck is putting out more than that.

Truck is tuned for the injectors in it.

 

[bullfrogjohnson]

You guys missed the point here. The tune is commanding a certain psi and the truck is putting out more than that.

Truck is tuned for the injectors in it.

Does the truck smoke worse when the rail psi is spiking, or does it not make a difference?

 

[chevyburnout1]

Just throwing this out there but when i had a funky Fuel Rail Current table in EFI Live this was the exact problem I was having. Just minus the smoke.

 

[Porno Joe]

Just throwing this out there but when i had a funky Fuel Rail Current table in EFI Live this was the exact problem I was having. Just minus the smoke.

Well that's definitely a possibility. Have to get with Caleb for that.

I checked this morning:
Start up the truck cold in the garage, it's fine
Drive like 2 miles. Put it in park, rail starts climbing. Shut off.

Start it maybe 5 min later. Rail starts climbing at idle - roughly 7000 vs 5500 desired. If I step on the gas pedal even just the slightest amount and bring the rpms up a bit, the actual rail psi comes back down to desired. Let off it climbs.