On Sun, 05 Oct 1997 16:52:10 -0400 siegfried <sdoerrer(at)ix.netcom.com>
writes:
>Took the SV to a local mechanic to "tune-up" and whatever it took to
>pass NJ emissions test. Seemed like a honest chap - got the job done.
>
>He mentioned that my timing was far to advanced - so he reset it,
>synched the carbs, and adjsuted the valves.
>
>Car did not run very well at higher rpms and acceleration as a result
>(also was prone to overheat) I tried to check timing with strobe but
>didn't really get anywhere so I got on the freeway, and reset every 1
>mile until its felt right. Result: runs well at higher rpms, rougher
>idle, no overheating.
>
>I have no idea how far off the timing is but have the following
>questions:
>
>1) Is the No. 1 cylinder the one closest to firewall or closest to
>radiator (for strobe).
Front most on the car.
>2) My crankshaft pulley has only 1 marking: is that Odeg BTDC?
Should be.
But there are marks on the timing cover to tell the degree.
See the alpine manual WSM 124.
>3) If true that my timing is too advanced, do I have to be worried
>about premature wear&tear? Is the rough idle probably due to "valve
>adjustment"
Does it ping?
Does it start ok?
If one or more valves is set too tight, or if the adjustment was done
cold, then you may very well have loss in compression on those
cyls.
Compression test may show this one.
Check thy own valve lash "Its really important".
Heres one for the books.
I had a surprisingly simialr problem very early on in my car.
Shortly after purchase from DPO, I experienced frequent overheating,
and lack of power beyond 4000 RPM.
It took some research, but the clues that brought about the
solution was in that the distributor was rotated with the vacuum
advance mechanism pointing towards the rear, but not quite
parallel to the block. Removing the dist, and pointing it in the
correct direction only made the misfire at an even lower RPM.
The deal was this:
The oil pump had been installed, and not clocked relative to the
crank #1 TDC per procedure. This resulted in a minimum of
one half tooth error at the best possible adjustement on the dist.
Just rotate the distributor you say?
The opening of the points, and the rotors position in the cap must
correlate through the entire mechanical edvance of the distributor.
In my case, the idle position of the rotor was dead middle of the
tang relative to the cap pole, and it ran OK.
As the distributor advanced, the tang advanced beyond the cap
pole, and the spark had to jump a longer and longer gap to spark
at higher and higher RPMs.
Timimg will have been adjusted correctly, but the engine just
doesnt run right at some RPM. If the oilpump had been installed
in another orientation, it may well have had a poor idle, and
a lively top end "which I may have chalked up to a lively cam".
The correct fix would have been to remove the oil pump, and put it
in correctly, but I was not about to try that.
The cheap fix, was to modify the rotor to point to a further advance
point, and to grind away the forwardmost part.
The alpine early alpine has an odd number of teeth on the cam
which means the clocking on the disributor will only function correctly
if the oil pump to the cam gear is exactly positioned per procedure.
>4) How many others time according to the book? and who else throws out
>the book and adjust by feel? Is this an acceptible practice?
Yes, to the point of detonation, then back it off a few degrees.
This assumes that the all the advances are working, and that the
static timing isnt so advanced as to make starting tough on the
starter.
The point that you arive at should not be too far off the factory
timing specs if the engine is running, and set properly.
Jarrid Gross
This archive was generated by hypermail 2b30 : Tue Sep 05 2000 - 09:59:42 CDT