werid CIS-3 timing problem

[ed armstrong]

Javad,

Thanks for the advice. I'll start playing with the
timing a little more.

Last night I did a little more troubleshooting and it
definitely seems to be jumping to different timing
maps. I warmed up the car and drove around a little,
checked the timing and it was retarded (> 0).  Waited
a little while, restarted the motor (still warm) and
it was at 6 BTDC ! Then drove it and it retarded
again.
These checks were with no fuse in the FPR.

With the fuse in, the engine characteristics really
change: Idle comes up and then stabilizes at 720rpm,
timing stablizes at 6-7 BTDC and curiously the vacuum
at idle _increases_ to 16 inches from 13 inches !

Very weird stuff !


--- JShadzi at aol.com wrote:
> Well, one think you're finding is a quirk in the
> CIS3 ignition system, yes, it does have different
> maps for high and low octane (pinging or no
> pinging), even the slightest pink will send the
> ignition into the "regular fuel timing map", in
> which all timing is retarded.  Restarting the car
> probably solves your problem right?  That's becuase
> each time you restart the car is begins in the
> "premium ign. map" and the process starts over
> again.  You should try retarding the timing another
> degree or two and maybe richening up your CO a
> little.  Another strategy is advancing the timing a
> little so that when it does go into the regular ign.
> map you'll have a higher base timing.
>
> Its kinda tricky, just keep playing around with it
> and see what works for you, don't worry about a
> little pinging here and there, these motors are
> tough and can handle it for the most part.
>
> HTH,
> Javad
>
> >
> >Yup, done all that. Car warm, idle at 720 rpm,
> mixture
> >OK. I'll do more troubleshooting tonight and see
> what
> >I can find.
> >
> >
> >
> >--- JShadzi at aol.com wrote:
> >> Make sure you set your timing with the car warm,
> at
> >> 800rpm,  and with the fuse in the FPR, have you
> done
> >> that?
> >>
> >> Javad
> >>
> >> >Hi
> >> >
> >> >I've run into a wierd CIS-3 ignition timing
> problem
> >> on
> >> >my 90tq conversion. The thing is that when I set
> >> the
> >> >initial idle timing to 6-7 deg BTDC, after a
> drive
> >> >around the block it is retarded, I not sure
> quite
> >> how
> >> >much, but at least 7 degrees.
> >> >
> >> >If I put in the fuse on top the fuel pump relay
> as
> >> the
> >> >Bentley calls for (for checking idle timing) the
> >> >timing comes back to 7 BTDC. Its like its
> switching
> >> >between timing maps or something !
> >> >
> >> >Any ideas on this one ? The car does at times
> seem
> >> >sluggish off idle as one might expect for
> retarded
> >> >timeing.  Other times it seems OK.  I should
> >> mention
> >> >this engine is 8.5:1 compression unlike the
> stock
> >> >10:1.
> >> >
> >> >Some other diagnostics. Idle is fine at 730 rpm,
> no
> >> >vacuum leaks, no knocks or pings, decent 91
> octane
> >> gas
> >> >used, knock sensor seems OK, no error codes.
> >> >
> >> >=====
> >> >-ed
> >> >
> >>
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> >
> >=====
> >-ed
> >
> >__________________________________________________
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=====
-ed

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