If someone could give me the diesel for dummies course on fuel lift pumps and high pressure pumps I would be a wiser ctd owner. What I would like to do is install a fuel pressure guage. I have used the search engine but still have some questions.
1. From what I understand the guage is attached to a banjo nut on the lift pump. Is the lift pump the same as the fuel pump and if not whats it do? Why do you monitor the lift pump and not the fuel pump ( if they are diferent)?
2. Do you run fuel into the cab or is there some kind of transducer.
3. I live up in Canada, specifically Alberta, where can I get a banjo nut. I have seen the geno's garage site where they are sold in a set and wonder why you would need to change the set?
4 I feel that it would to benificial to monitor fuel pressure to inform you on fuel filter statis and fuel pump condition. Am I right?
5. Since I'm here please explain the importance of monitoring boost. What's it indicate if its low and what are the normal readings?

Thanks for all the great info and thanks for your responses.
Jerry

 

I'm no expert here, but I'll answer what questions I can for you.

1. The lift pump and the CP3 are two different animals. The lift pump supplies fuel from the fuel tank to the CP3 at relatively low pressure. The CP3 supllies the high pressure fuel to the rail for the injectors. As I don't have a fuel pressure gauge in my truck, I can't say for sure where it connects, but it is my understanding that it's monitored after the lift pump (someone correct me if I'm wrong here).

2. It's never a good idea to run fuel into the cab. That being said, it's either an electronic gauge or uses a tranducer to read the pressure.

3. Rod at Wildcat Diesel has always been a great help, and knows his stuff. Give him a shout.

4. Most people monitor the fuel pressure to keep an eye on the lift pump's health. In the 2nd gen trucks they had a bad reputation for going bad. When the lift pump starts to fail (not supplying enough fuel to the CP3), then CP3 failure is possible as well.

5. If you intending on modifying your truck at all, knowing what kind of boost level is good for a few reasons. The stock headgasket is supposed to good to between 50 and 60 psi. I'm sure there are others that have gone higher than this number, and some that have failed below this number. On a stock '03-'04 HO motor, boost is around 25-26psi. On a stock '04.5 motor, the boost is between 28-35psi. I'm not sure why the wider span on the '04.5, but a friend of mine has one that pegs a 30 psi gauge and the truck is bone stock. If boost is low you will encounter low power and higher EGTs usually.

I'm sure others will chime in with better answers. Hope this helps some.

 

One of the best known diesel shops is also in BC, Piers. I'm sure they could supply the fittings.

 

Thanks for the help. I was wondering if its possible to monitor the pressure from the cp3.

 

The fuel pump for the injectors can generate pressures over 20,000 psi. Finding a gauge for that will be a tough one.

 

If you have a Jacobs exhaust brake you can't plumb into the low pressure feed line on the pump due to the vacuum pump being in the way. The low pressure line is the line going from the BOTTOM of the fuel filter forward to the CP-3 high pressure pump. Since I have the Jacobs I just replaced the banjo fitting on the bottom of the fuel filter with the banjo sender for my X-monitor. Hope this helps.

Richard