Your .75 bar at maximum high fuel feed rates when accelerating hard at speed is probably about as good as it gets. If not it is certainly more than adaquate.

You also mentioned that normal pressure is good for cold starting. It was suspected earlier and since proven I believe. I credit Mr.Hunter by the way for this.

I think thats principally why our Mr. Hunter has rebuilt quite a few lift pumps this past winter. I still wish he would post any viewpoints he has developed in this area. It is pretty obvious he has probably been checking pressures.

I still feel this cheap mechanical dampened gauge (about ten dollars) should be a permanent installation. It could be hidden in the glove compartment or somewhere. You really only need to check it periodically.

Although it must be visable at speed when you want to examine the pressure. Perhaps the present originator of this thread can describe where he placed his?

There is real established evidence of fuel milage decline with low pressure. To what extent I am not aware but it is claimed to be easily noticeable when the pressure is really low.

This often reported effect originally got me thinking and starting to post in this area some time ago. The fuel milage to a simple guy like myself should have been better.

Anyways it makes me feel good that serious consideration of this area is now occuring. Hopefully many more posts of gauge users will occur with time until we have a lot more knowledge. I look forward to learn a thing or two from you fellows that are taking the effort.

If the cam lobe for the lift pump reactivates the lift pump cycle when number one element is loading.Or just prior to it loading. Remember the stored energy stroke to the lift pump is only applied once per injection pumps complete cycle.

Then after exhaustive thought I think it might be reasonable to saddle the failures or at least the constant heavier loading of the number one rod bearing. On very low to almost non existant base fuel pressures.

More of the engines running work load is being serviced by the number one cylinder then. Other effects like individual cylinder timing being more retarded in comparison to the number one cylinder are contributing I believe as well.

It may always be running under more stress or loading than it should when pressure is substandard. On this basis it is just going to wear that number one rod bearing out quicker over time than the other bearings. .

As time goes on this earlier speculation of mine is becoming both more logical and other than absolute poof being presented it should probably be taken very seriously . At this point if you own a 616 engine especially.

If you run with virtually no fuel pressure in the base of the injection pump at speed. There is more than a fifty-fifty chance you are loading the number one rod bearing somewhat more compared to any other individual rod bearing in the engine. Just too many items now point directly there to ignore.

Your car can still run fairly well with very low supply pressure. So low fuel supply pressure might be quantified at this point as a potential silent engine killer. Why take the risk? Check your pressure. It really might just save your engine over time. There are also many other important benifits to having reasonable pressure as well..