Cheap F.Pr. Mod

[fordoor]

After ordering a higher strength fuel pressure regulator spring($20.)to help increase pressure, I realized this Mod would probably put a little more strain on the stock pump and system. Is this anything to worry about? Some guys are bb shimming the spring for that little extra bit Just wondering what y'all thought.

 

[DaveBen]

Those are 7.3 engines that are getting shimmed.. I have never heard of anyone shimming a 6.0 engine. I don't think it can be done.?.?.

Dave

 

[fordoor]

Those are 7.3 engines that are getting shimmed.. I have never heard of anyone shimming a 6.0 engine. I don't think it can be done.?.?.

Dave

We have a fuel pressure/bypass regulator mounted on the secondary fuel filter housing. The bypass allows fuel to return to tank that is over the pressure of the spring tension. The theory must be that this spring fatigues over time and reduces full potential of fuel pressure. I am replacing this spring with a stronger one from Gillett Gillett Diesel Service Inc - Mechanical Engine Performance Upgrades This will only show improvement if my stock pump can pump up to a greater pressure than the stock spring; which is what I'm hoping for. It's only $20. and 20min.'s so it's a good starting point. The shim thing I was refering to is that I've heard some guys install BB between the spring and the return line plunger to get that little extra bit. I haven't received spring yet so it's all theory at this point.

 

[DaveBen]

Keep us informed as how it goes. Maybe I would be interested!!

Dave

 

[fordoor]

Keep us informed as how it goes. Maybe I would be interested!!

Dave

I will Dave, no prob. Like I said, it all sounds good on paper; we'll see.

 

[bismic1]

The GDS spring takes you way over the 75 psig that Ford recommends as the max pressure for the injector o-ring protection. I tried it. I even cut off a few coils and it was still way high. The 6mm BB mod works quite nicely in most cases (took me from 43-50 psig range to 53-60 psig range). I still have the spring (minus the coils) - you are welcome to it for the price of shipping.

Just as an fyi (IMO) - no fuel pressure mods should be done without a fuel pressure gauge.

 

[fordoor]

The GDS spring takes you way over the 75 psig that Ford recommends as the max pressure for the injector o-ring protection. I tried it. I even cut off a few coils and it was still way high. The 6mm BB mod works quite nicely in most cases (took me from 43-50 psig range to 53-60 psig range). I still have the spring (minus the coils) - you are welcome to it for the price of shipping.

Just as an fyi (IMO) - no fuel pressure mods should be done without a fuel pressure gauge.

Good info.; Thank you. How much "way over" was it when you installed it? And how much over was it after you cut a few coils. You would think that GDS would have done the homework on this spring so that it wouldn't be detrimental to their customers. I do have a gauge, but I'll be calling GDS now to ask what they say is approximate rating on this spring to compare with what you actually had. I still haven't received it yet.

 

[bismic1]

Good info.; Thank you. How much "way over" was it when you installed it? And how much over was it after you cut a few coils. You would think that GDS would have done the homework on this spring so that it wouldn't be detrimental to their customers. I do have a gauge, but I'll be calling GDS now to ask what they say is approximate rating on this spring to compare with what you actually had. I still haven't received it yet.

I was at 85 psig at idle. I cut a few coils off and was still at 80 psig.

GDS will say that they have worked with international and that the injectors can take the high pressure. I did not contact GDS, but someone else (on another forum) did. They (GDS) do not believe Ford (or their mechanics) when they say 75 psig is the upper pressure limit for the injector o-rings.

I have read too many threads from techs that say they do see o-ring leakage at high pressures.

 

[fordoor]

I was at 85 psig at idle. I cut a few coils off and was still at 80 psig.

GDS will say that they have worked with international and that the injectors can take the high pressure. I did not contact GDS, but someone else (on another forum) did. They (GDS) do not believe Ford (or their mechanics) when they say 75 psig is the upper pressure limit for the injector o-rings.

I have read too many threads from techs that say they do see o-ring leakage at high pressures.

GDS said just that when I called them today. They also say they have sold thousands of these springs without issue. Perhaps the leakage problems that are being refered to are from high pressure aftermarket pumps that get turned up to 100+psig in addition to the greater volume that those pumps are capable of. I'm going to give this spring a try. I haven't heard of this as a problem here on this site and I really want to check out the difference that it makes w/my stock pump. Perhaps my stock pump is only capable of 75psig; we'll see.

 

[bismic1]

GDS said just that when I called them today. They also say they have sold thousands of these springs without issue. Perhaps the leakage problems that are being refered to are from high pressure aftermarket pumps that get turned up to 100+psig in addition to the greater volume that those pumps are capable of. I'm going to give this spring a try. I haven't heard of this as a problem here on this site and I really want to check out the difference that it makes w/my stock pump. Perhaps my stock pump is only capable of 75psig; we'll see.

I will practically guarantee you that your stock pump can get to 100 psig. That is the design. If it can not produce that pressure, your pump is failing or there is a restriction.

It comes down to believeing them or believing Ford. I will repeat - Ford specifically states in literature that risking injector o-ring failure can begin at 75 psig. There is no question as to the meaning of their statement - it is specific.

IMO - The wise person will be conservative. Running OVER 60 psig will get you absolutely NO benefit (this is not a 7.3L diesel). The only thing you need is to ALWAYS keep the pressure over 45 psig since this is the leading cause of injector damage (low fuel pressure - another Ford statistic). More pressure does NO good. You want enough pressure so that at WOT you will not drop below 45 psig.

Do what you want, but it is an expensive risk.