Base Timing Problem

[sleepydsm]

When I tried to set my base timing awhile back I had a problem. The timing mark was jumping all over the place. I have set the base timing before on these cars many times, and it normally sits still in one spot. My problem is the timing mark moves very erratically.

*Grounded with a jumper wire to the battery
*Timing light hooked to #1 plug wire

Any one have ideas? Bad CAS?

[blackrosenova400]

Yeah I notice when I set my timing, mine is somewhat stable, but sometimes it jumps. I cant remomber if it jumps advanced or retarded though. I wonder if mine is going bad.

[C3L1CA]

Maybe the pulley is starting to separate, a bad wire/connection when grounding the plug out?

[Shane@DBPerformance]

If you rev it up a little bit, it might get more stable. With the timing connector grounded, it should stay locked at 5 degrees, regardless of RPM.

[Goat Blower]

Mine bounces around a little bit, but still easy enough to adjust base timing to.

[sleepydsm]

Hmm, it just seemed more erratic than it ever has before, I'm just assuming some 16 year old part was dying.

[x-pride]

Mine jumps all over the place too when the idle is at 500 RPM. If I raise the RPM to 900 the base timing stays at 5. What is your base idle?

[sleepydsm]

Ha, well I honestly dont remember. I've fucked with the BISS screw a lot and my ISC hates life (aka the grim reaper took it), it's been three weeks since I've driven the car. I wanna say just shy of 1000, without balance shafts and poly mounts it rattles the interior less at a higher RPM.

Now that I've said that, for setting the BISS Screw idle adjustment I thought you only had to ground the same plug that you use to set timing. Is that the only thing needed, as I've heard mumbling about the diagnostic port...

[Spyderturbo007]

You also have to ground pin #10 on the diagnostic plug assuming it's a 1g.

On a side note, I don't see anyone's vehicle information in their profile. Is that normal, or am I missing something? I see that mine comes up under my username, but I don't see anyone elses'.