>Hi everyone;
>I had a great weekend - spent Friday getting the car in order, and Saturday
>and Sunday bombing around town.... what fun!
>
>I am still trying to figure out something with my de-smogged and
>header-equipped U20. I've posted about this before, but now that I have
>some bugs ironed out, maybe someone can give me better direction. The car
>is a '69, but I can't say about the engine - I think the engine number is
>something around 11,xxx... (IOW, it's an unknown hodge-podge engine)
>
>Basically, the car feels like it's running out of gas at 5000 rpm. It will
>pull pull pull like there's no tomorrow, until it hits 5,000, then it's
>just like the carbs are blocked - no more flow, the exhaust tone changes,
>and the car slows down.
>
>I thought it might be float settings (enough gas to get me to 5K, but then
>no more), but *gently* taking the car to 4000 and punching it yields the
>same result.
>
>The valves have all been adjusted, the timing is about 10BTDC. I have set
>the carbs and balanced them. I pulled the breaker plate from the dist and
>cleaned it up and relubed it.
>
>Nothing I've done has made any difference.
>
>I'm just about going nuts here - the car is fast and strong, but it would
>sure be nice to get some more revs out of it.
I wouldn't be at all surprised if you're running out of gas due to low
fuel pressure, at least at higher RPM. This is best checked under load,
at speed. Of course, that's not too easy, either, but it is doable. Are
you running just the OEM mechanical pump? Carter (I think) makes a
relatively inexpensive electric (around 4.5 PSI) which works very well
when combined with the Holley adjustable low pressure regulator.
>My only thought is that the distributor is either not functioning properly
>or needs modification for improved performance. The vac advance (as viewed
>from the indicator tab sticking in from the advance body) moves, but not
>much, as the engine is raced about. Of course, this is under no load, so I
>don't have a clue as to what it's supposed to do. Can someone help me out
>with the proper action of the vac advance, or a vac spec (duh, shoulda
>thoughta that - probably in my manual)...
>
>I've heard of recurving the distribtor - what's involved? Is is as simple
>as replacing the mechanical advance springs or what? Is it a DIY, or a
>send-it-out-to-some-pro-who-knows-what-he's-doing modification?
I doubt the problem is the distributor. Even a recurved distributor
should be fully advanced well before 5K, usually all advance is in by
2500-3K at most. The specifics of recurving have been discussed before. I
seem to remember a reference to info on Gordon's site?
HTH, Ron
________________
Ronnie Day
rday@airmail.net
Dallas/Ft. Worth
'71 510 2-dr (Prepared class autocrosser)
'73 510 2-dr (Street Toy)
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