Woohoo, thanks list!
Even though the Red Wings game kept me up late, the A was calling to me so I
got up real early with the hopes the fix would be simple.
Decided to start with the mixture since that was the easiest. The piston
pin lift test indicated a lean mixture, which kinda surprised me as my plugs
are a nice light tan colour. Still figured it couldn't be too far off.
Ended up only turning each mixture nut 1 1/2 flats to get it nearly perfect,
per the piston pin lift test. Now the drive to work to test it (@20 miles).
Well, I'm happy to report that it pulls very strong to 6k rpms, and seems to
want to go further. No miss, no loss of power. Problem solved. With
tomorrow supposed to be a perfect day, I will now have a time for a few hour
ride before the Wings game!
Thanks again all!
Gordie Bird
62 MGA
80 MGB
86 Audi 4kq
> At 12:59 PM 4/13/2000 -0400, Gordon Bird wrote:
>
> >Had the A out last night, after normal valve/points adjust,
> etc,etc. Fine
> until warmed up (@190F), then at @ 5000 rpm's I get a miss and loss of
> power. Pulls just fine up to that point. When cold, pulls
> strong up to
> red line, when I quit. I know Barney, it should be able to
> go higher. ;^)
> Any clues?
>
> Turn the carburetor mixture two or three flats (1/3 to 1/2
> turn) richer,
> and give it another try at top end (might idle rough). If it
> runs better
> at speed that way you may need richer needles. Check the
> numbers on the
> side at the top end of the needles (have to remove to see) to
> verify that
> your car still has the original needles. When I bought my
> car it did the
> same thing, ran great up to about 5000 and then sputtered at
> higher engine
> speed. Turned out to be the wrong needles in the carbs.
>
> If a richer mixture doesn't fix it, start checking around the
> distributor
> contact points for high resistance grounding or a bad
> condenser. Use an
> ohmmeter with a milliohm scale to check resistance through
> the distributor.
> From the terminal on the side of the dizzy to the engine
> block you should
> get no more than 1/4 ohm with the points closed (250
> milliohms max). If
> you find higher resistance there it needs to be fixed. Maybe
> the points
> are burned. Maybe the body of the dizzy doesn't have a good
> clean contact
> with the engine block. And there is that generally invisible
> wire under
> the moveable contact breaker plate to ground the moving plate
> to the body
> of the dizzy. This is supposed to be a finely stranded and
> very flexible
> wire, but with extended use and age it can still break
> (usually near one
> end). A broken wire here can give an intermitent contact
> that checks out
> fine at rest but fails when the vacuum advance kicks in and
> rotates the
> breaker plate.
>
> Let us know what you find,
>
> Barney Gaylord
> 1958 MGA with an attitude
> http://www.ntsource.com/~barneymg
>
|