How to tell if CP3 is out of fuel????

[silver03]

I hear alot of talk about the CP3 pump being the limiting factor on the new GEN 3's. How can you tell if the pump is running out of fuel?? I have stage 3 injectors, pressure box, and TST on mine and can not tell if this has happened to me???

 

[Wayne M.]

I would have to say the answer lies with the 2G guys and what they do. Geno's has a fuel filter cap with a schrader fitting on it that is used as a tap for a gauge. I would say install a gauge and that reading would tell you how your transfer pump pressure is. It's becoming obvoius that our injector pumps are sensitive to starvation. If that engine is working real hard, and that pressure/supply goes away-you have trouble.

 

[KLockliear]

You need a gauge. You have addressed the problem with your preporator, but without a gauge you won't know if it is keeping up.

 

[Jengle]

Fuel pressure gauge located post filter, so it measures exactly what the CP3 is getting.

 

[d90boy]

The question refers to whether the high pressure pump has run out of capacity, not if he has exceeded the transfer pumps capacity if I read it correctly. With those mods he can easily exceed the CP3s ability, going by what Keith has said in the past concerning the reason why they don't go above stage III injectors.

 

[Jengle]

You're right d90boy. I missed the question. On that, I think we will have to wait a while for a modded CP3 with increased capacity. Porbably won't be too much longer.

 

[Badunit]

Isn't there a pressure sensor on the high pressure line? Maybe you could temporarily wire in a multimeter and see if the pressure is going down when it shouldn't be. Actually, that would be an interesting gauge to have permanantly.

 

[BCarmicle]

I've got my fuel pressure gauge going in before the pump. Is this correct or would it need to be installed after the pump to get an accurate reading?



Brandon

 

[bpenrod]

after the high pressure pump would not be a good place for a guage, the pressure there is somewhere north of 23,000 psi if I'm not mistaken. I think the qustion boils down to how much fuel can the CP3 pump while maintaining the required pressure?

 

[GWoody]

FloorIt, a member over in Kansas has been researching this very issue, I think he has been talking to some gauge manufacturer about buying a very high pressure gauge to check and see whats going on with the fuel flow from the CP3.

 

[RBender]

I think the question boils down to how much fuel can the CP3 pump while maintaining the required pressure?

The data plate on my CP3 pump, which was replaced last month under warranty (the internal high pressure sensor failed) reads:



CR/CP3S3/R1. 10/30-789S



CR: Common Rail designation

CP3: Pump Family

R: Drive direction (L or R)

1. 10: Theoretical pump output in mm3/rev



I'll leave it to others to figure out the relationship between the engine speed and the speed of the CP3 pump, and to do the metric conversions .

 

[Digger]

Without attaching a gauge of some kind how can one find out if the CP3 is running out of fuel? If you can't pull a gauge down past 10psi before the pump it would seem to me that the CP3 producing 23,000psi would keep up just fine. I just can't make any sense of this.

 

[Vaughn MacKenzie]

Guys, I don't think you need to purchase some fancy high-pressure gauge. It should be possible to tap into the wiring to the pressure sensor that is already there and correalate voltage readings to actual pressure.



Several months ago someone posted all the resistance (or was it voltage) values of the high-pressure sensor for a wide range of pressures. It shouldn't be difficult at all to build the circuitry to make a digital gauge that will tell you exactly what the rail pressure is. Frankly I don't understand why none one has built one yet.



Vaughn

 

[jcarey]

Some of the OBDII software for PCs/PDAs will also report the fuel rail pressure. AutoEnginuity, on their wev site, states that they do.



http://www.autoenginuity.com/sensor_list.html



Jim

 

[Digger]

I would think that someone has tried this. I have seen many of trucks that are running stacked boxes, twins, injectors and but down well above 500hp on the dyno. None of them seem to be running out of fuel. They still have smoke at high rpm, boost. I can't here any of the breaking up noise they have been claimed to do when they are out of fuel either.