I recently purchased a 78 midget (1500cc). When it was bought, it idled
(and ran) rough until it warmed up. Once it warmed up, she smoothed down
considerably. Upon checking the timing, I found that it was a 4 degrees
ATDC versus the 10 degrees BTDC my trusty Haynes manual told me it should
be.
Once changed, I readjusted the idle. Now on startup and warmup, the car
idles great (i.e. no stalling, choking, and other actions showing that
it's pissed that it's running.) BUT now when I drive it, it hesitates
until it gets going (about 10MPH or so). Also, when I increase the RPMs
without a load (not in gear), I can hear it sputtering at around 3K RPM.
My guess would be occastional misfires. Also, I can faintly smell gas out
the exhaust, (But no black smoke).
The plugs are recently cleaned (And brand new) bosch platinums. Wires and
distributer cap and rotor and coil are new. ALSO, the auto choke has been
removed and replaced with a manual choke.
The idle is set at 1000RPM, the carb is a zsCD (on the top of the carb it
says CD, I assume it's a 150CD4T but I haven't seem that number on it
anywhere. Tonight I'm going to fill the damper with 10W30 (I checked it
last night and it's relatively full, but just in case).
I also used some fantastic and sprayed it around the carb to check for
leaks. From what I understand, leaks would have caused the rpms to
increase when the fantastic was sprayed.
Finally there are a few items on the carb I can't identify on the front.
1) a small air port facing straight up (about 1/8" ID) 2) a recessed air
port facing straight forward (There's a plugged piece of black rubber in it
that's shaped like a pipe elbow (about 1/2" in diameter where it fits in
the carb). and 3) a small screw with a spring on it on the front of the
carb facing straight towards the front of the car. It's a regular head
machine screw for around 3/4" deep, then it tapers smoothly (No treads)
from 1/4" down to about 1/8" over a legnth of about an inch.
ANy help on this long email would be appreciated.
SO the question is, is this a carb problem? If so is it simply a retuning
issue? And finally, what's the best way to tune it without going to a
mechanic (I'm saving up for 2 Weber Side Drafts).
Mike
BTW, since I'm new to this, I've included all the info I think is
needed. If I sent irrelevant stuff, or didn't supply needed info, please
correct me.
'78 Midget
'87 300zx
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