I have '97 f-250. The only mods I have installed on the truck is a tymar air filter set up, a coolant filter, and no muffler (only has the resonator or cat on it,whichever it is because that was how the truck was when I bought it 3 year ago). Yesterday I installed a new fuel filter, cleaned the screen on the fuel pressure regulator (it was filthy), and done the fpr shim mod using a bb. Is there anything that I need to watch for on the fpr mod that could cause me any problems or damage my truck. I took a before and after fuel pressure reading, but the guage needle was bouncing so much that I could not get real good readings, thanks for the advice/comments in advance!!!

 

could you tell a differance before and after?

 

You'll need to get an accurate fuel pressure reading.. Then go from there.

 

I could tell some difference on the guage and some in driving the truck, but it was minimal or maybe even my wishful thinking in driving it. The needle on the guage bounces so much that it is hard to find the median pressure.

 

This link may help.

https://www.ford-trucks.com/forums/5...mming-fpr.html

Bouncing fuel pressure readings make it hard to determine the actual FP. Kinda average it or use the highest reading for reference.

 

I removed the bb from the fpr, and could tell no difference in the running of the truck. I believe the difference I noticed was from the new filter and removing the crud off the pre-filture screen. But with the bb removed, I put a guage on truck. I am using an actual fuel pressure guage, not a tire guage. When the guage was bouncing, I recorded the low and high readings. Without a shim I am getting around 40 on the low side and 55 on the high side. When I install the bb shim I get around 64 on the low side and 85 on the high side. If anthing above 75-80 is bad, than the bb shim is to much for me correct. Also, this mod will only cause smoother idle, no power??? Thanks!!

 

Cuda in the link you put above, you comment: A fuel pressure gage from a gasser will work as long as it goes high enough. , and I just bougth the ACTRON kit profesional pressure test CP 7838, in AUTOZONE in Mexico, and they told me that I could use it to test my DIESEL TRUCK, but in the manual says: Never use fuel pressure tester kit on DIESEL or FLEX fuel engines.

Can I use it to test my Diesel Truck or what happens if I do? the tester will be damaged?
p.s. what is FLEX fuel engine?
Thanks in advance.

 

Sounds like you have one that will not work on a diesel. The diesel may attack the rubber or plastic components of the gage or the hose if it has one. All of the FP gages I've used didn't have the warning yours has but I ususally tend to ignore that sort of stuff especially if it has a warranty...it's your call tho. Maybe you could exchange it for one that is compatible with diesel. You may need one in the future for the flex fuels that are getting more & more use these days. Flex fuel engines are designed to use a higher percentage alcohol content. Alcohol is the stuff that attacks some rubber & plastics.

 

You need an oil dampened fuel guage that will smooth out the functional fluctuations and give you somthing you can read.

Another method is to use a stick type tire pressure just be sure to wrap some rags around it cause fuel is gonna squirt. This will give you the peak pressure reading.

 

I used a liquid filled gauge from grainger.com. Cost was about $8. It still has some bounce, just as described by JR270. For another $.35, I bought an elbow to mount it permanently.