Fuel Pressure Regulator

[lsmull]

Hello,

I'm brand new on your forum. I've read quite a few posts and greatly repect your experience as well as your willingness to spend time sharing it.

I just took a leap of faith and purchased a Scorpion long distance that will be shipped to me. The car has a Beta 2.0 conversion and new DATRA carb. The package was supposedly well-tuned after installation. However, the seller tells me he thinks the fuel pressure regulator is bad because the car tends to flood after it warms (he said a half an hour or so). I would like to replace the regulator with a variable rate regulator (1-4psi) and was looking at the Holley models. Do any of you have a specific make/model recommendations based on what's worked for you?

Thanks very much, Lynn

[SubGothius]

My initial impression is to wonder whether it is actually flooding, or if that is the PO's diagnosis or euphemism for a set of symptoms which may or may not indicate literal flooding. It sounds more like some sort of heat-soak issue to me, or possibly choke-related? Have the PO describe what behaviour he means by "flooding", or describe them to us once you get the car yourself. Does it just spontaneously die after it warms up? Or merely fail to start when warm? Can it be restarted by holding the throttle open (i.e., holding the pedal down while cranking -- something I occasionally need to do for warm starts)?

Oh, and Welcome Aboard. :)

[Will]

I agree with Tye that your problem is with the carb and not the supply pressure if you are using the stock (scorpion) pump. The reason for this is that the stock pump uses a magnetically coupled impeller that limits maximum static pressure to around 5PSI, I have verified this experimentally by feeding the stock pump up to 15V and measuring in water column, the Weber should be capable of taking 6-6.5lbs before unseating the valves (yeah, some people will say the Webers "like" 3-4lbs but an otherwise healthy DATRA will not leak when driven by the STOCK scorpion pump. If you have a later pump, for example my Holley Blue that puts out around 19PSI then you need a regulator and in most cases a return line to the tank in order for the regulator to work properly.

More likely IMO is that your float level is set improperly UNLESS you have an aftermarket pump. At any rate, I'm sure you'll find the problem easier to diagnose when you have possession of the car, it may be immediately self-evident (use of an FI fuel pump for example).

Welcome from me too.

[lsmull]

Thanks guys and I'll cool down until I get the car when I can try a more systematic diagnosis. He did say the car died after a half hour or so. I'm inclined not to ask him any more and just see what I bought when it gets here. Oh boy

Lynn Smull!