1986 Crusader 454 electronic ignition conversion problem

Hi all,

I converted my port RH engine to electronic ignition using the complete Sierra conversion kit (includes the entire distributor) and followed the instructions.

I removed the ballast resistor, timed at the flywheel 10° marks at 650 rpms and used the included timing tool with a conventional timing light.

Engine idles fine, runs well at low speed, the problem arises around 1900 rpms, engine sputters and backfires, but when I push the throttle through it snaps out of it around 2300 rpms then runs fine from there upwards. Same thing decelerating, sputters around 2300-1900, then fine.

There are also moments when the rpms will shoot up/down disproportionately to throttle adjustment up and down (never did this prior)

Engine never behaved this when it was a breaker point system.

I called Sierra they sent me a whole new kit, new one is doing same thing.

I suspect there is something going on with the timing advance on this aftermarket product and maybe this isn't a good fit for my engine.

At this point I'm considering ripping it out and going back to points and breakers. I need to get this squared away because the other engine needs updating and don't want to install another problem system on that side.

Thanks for your input.

Assuming the Sierra kit you used is the Delco EST clone, there's not much to do assuming the issue is the distributor...I think the best approach to installing the EST systems is to set the timing so that the engine sees full advance at 3500 RPM and then live with the timing at idle and midrange...the timing adjustment is 'in the module' and is not adjustable and far from optimum.

The only other thing to check is that the IGN lead to the coil provides a solid B+ when the engine is running...sometimes the factory crimped wires aren't done well..

Junk that sierra kit, and switch to a Pertronix or DUI distributor.

Sierra products suck, IMO, they're all rebranded, mostly Chinese junk. I'm not particularly fond of the Delco est distributor either. It's not bad, but as you're experiencing here, the timing and timing curve kind of sucks.

I checked mine with a light and my timing is very inconsistent, it flutters around 2-3 degrees constantly. Without moving the distributor or timing light, the timing, at times (geneally at idle), will jump around like a jackrabbit. I'm guessing it's the computer and distributor constantly "talking" and trying to make adjustments.

I hate it.

The ESTs, in stand alone mode, have a very steep timing curve and exhibit similar behavior at idle and off idle...

makomark said:

The ESTs, in stand alone mode, have a very steep timing curve and exhibit similar behavior at idle and off idle...

Click to expand...

Mako, any idea what would cause the timing light to go nuts (bounce all around 3-5 degees) at idle with an EST distributor. Doesn't seem like the gun is reading right, but it's a rock-solid $300+ snapon timing light, that works well in every other instance. Even when the engine is in timing mode, the mark is all over the place. Engine is running smooth as glass at idle, but it sure seems odd that the EST distributor is flopping timing all over the place.

Hi,

I have a similar if not identical Snap On light.

I also have a Delco EST set up in my boat.

Go to the INC button and give the light +1 degree.

That will often help stabilize the the reading (flash) at the crank.

As Mark mentioned, the EST has a very steep adv. curve.

You may want to check your timing chain for excessive slack if the procedure does not work.

Good Luck

Jon Allen

If the EST is connected to an ECU, then the ECU will 'optimize' the timing continuously...