Shimming the FPR 99-03 7.3

[kiarasue]

shimming

I think was as easy as shimming but now I can adjust to what ever I want. You need the new cap from DI that has a 1/8 pipe port because you gut the factory reg. I mounted the reg on a alt bolt. Put 3/8 hose nipples in and use fuel injector hose. I had some parker push lok hose that has a working psi of 1250. I thought that should cover it. Gillette diesl told me he has seen 20hp on the ground with 105psi. I've run as far as 150 with a walbro pump. Very little change above 105. I run 95psi now. If you think going to 70 is great, move up to 100psi. I've done this for 40,000mi with no problem and the truck has 130,000mi on it.

 

[dboyw]

OK, well after reading this thread, I went and finally shimmed my truck. I get the kit from Pure Diesel Power. I put the gauge on first to see what my base was. 45lbs or 55lbs, can't remember number now, at idle and at 2000rpm, in driveway. I put the shim in and it went to 65lbs idle and 2000rpm. Getting ready to go for a drive.

Question. When I had the gauge on, but not the shim, fuel pressure would go up and stay there when the fuel pump shut off. Once I shimmed, the pressure will go up, but slowly go back down. There are no leak that i can see. What did I do?

 

[roosterdiesel]

It should bleed off pressure. If it doesn't you end up with a long cranking situation. I've personally seen this when my regulated return system didn't bleed for whatever reason.

Did you have a long cranking issue before?

 

[dboyw]

No, never had to crank it a long time. Starts up the same as it did before. About two cranks and we are up and running.





For no reason except that my daughter is here with me and wants a silly icon here.

 

[bdrummonds]

Make it easy and just order from Dennis for the Adapter

or....Garrett also has the complete Gauge Kit

Just in case anyone wants to source theses things locally, The adapter fitting can be found at a hydraulics shop. It is an male SAE 20 o-ring to a Female 1/8 NPT, the hose can be as simple as a grase gun hose( they're rated to 150PSI) a 100 PSI oil filled guage can be found at the same hydraulics shop, total cost $18.

Also anyone wanting to know the size of the AIH plug it is a 22MM by 1/2 inch. if you still have your R size drill bit and your 1/8npt tap(from your pyro install) you can drill and tap this plug to create a boost guage port where your AIH used to be. By doing this you dont have to cut your Map line.

 

[jisaacs11]

what kind of horsepower increase can you expect by bumping your fuel pressure to 70? does it hurt your mileage?

 

[CHPMustang]

Not sure about HP increases but the acceleration and overall behavior of the 7.3L is improved.

 

[kiarasue]

Fuel pressure

Bill, I know you don't agree with me on the fuel pressure setting. I have 40,000 on mine at 105psi. The engine has 130,000 on it. Everybody agrees that the boost to 70psi is great but the jump to 95 to 105psi is awesome. Gillette diesel has seen close to 20hp at the 105psi setting. I have run up to 150psi with no problem. There is just no difference after 105psi. If you build an fuel air seperator, You can eliminate the return line. And if you like to play, you can hook a second pump up to the return line and put a pump to each head. I have to much time on my hands!!

 

[black_cloud_stroker00]

don't mean to hijack this thread, but is this mod worth doing if I have a chip?

 

[roosterdiesel]

I have 40,000 on mine at 105psi.

Have you done any oil analysis or had your injectors out to see what your o-rings look like?



Black_cloud_stroker.....yes you will feel a bit more throttle response even with a chip.