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Old 02-19-2013, 12:32 PM
barry12345 barry12345 is online now
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Originally Posted by eatont9999 View Post
Why would you want fuel pressure gauges in the car after the problem is fixed? I can't see any reason why they would be that necessary.
They just for starters inform you when the fuel filters should be changed out. Also great early warning indicators of things like the lift pump may be failing or some form of obstruction is forming up in the system somewhere. Greatly aid in troubleshooting issues as well.

Running with low fuel pressure reduces milage. Reduces the quality of the engine idle and increases engine noise especially on the highway.

It is my somewhat unproven belief constant low fuel pressure will take the first cylinders rod bearing out over time. Almost for certain on the 616 four cylinder engines. Less certan on the 617 five cylinder engine but still a probability. There are some reasons the 616 engine is more prone to this.

Pressure gauge installed permanently or not. You should at least know where your fuel pressure in the base of the injection pump is. The upside of this is far greater than the downside. It is still fairly safe to say the vast majority of members at this time have no knowledge if they have even adaquate fuel pressure as these engines will still run seemingly decent at very substandard pressures. In my opinion there is a price to be paid for doing so one way or another.

The high milage expert on our site is not talking much. Still i think the fuel pressure he is running at is beyond what I suspect the recommended maximum pressure is. It is only one of a host of modifications he has done.

I am starting to think what he is doing in this area of boosting the fuel pressure higher is safe but still cannot recommend it without certain tests I would have to do.

At about thirty two miles per gallon at fairly high speeds I thought there was no further room for improving his milage. Yet he was getting 35 or more miles per gallon just awhile ago steadily. Drives a thousand miles a week as well back and forth to work and his observations are reliable in my opinion. He also does not vend cars on ebay. This is one heavy old 617 type engined sled he is doing this with.

I forgot to mention that good pressure increases power as well. So there is absolutly no downside I can think of to actually knowing you have it. Anyways if you have the gauge is it really of better use sittting in your tool box even if just installed in the engine bay? You had to hook it up to use it anyways.

Last edited by barry12345; 02-19-2013 at 12:50 PM.
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