Thread: MIsfiring ,too rich mixture, Need help

Looks like we lost a few posts over the weekend so to update this the latest is that we got the engine to rev well and act pretty responsively through changing the dissy position a fair bit ( car still runs very rich but at least it rules out the engine dropping a valve or other issues with timing chain etc.)
We noted that at idle and low revs that the battery was discharging and when it was charging was at 13.4 volts which I think is on the low side.
We suspect the alternator regulator is acting up and have pulled it out to check on Monday. I have read elsewhere that irregularities in the power will play havoc with EFI and suspect this may be the root of the problem.
Will update when have the alternator sorted and back in.

Had alternator checked and seems all is fine with it. Apparently it is not unusual for alternators to not start charging till they hit 1100-1200 rpm. So thats the good news and will see what the status is when back in and wiring checked.

G`day ,

alternators can cause a missfire as well as the wires .

I`d suggest if you can to run it before you refit the alternator as in no belt or wires connected and if the missfire is gone re-route the wires away from or shield the wires that are anywhere near the distributor and amp .

Thanks PLR thats a good suggestion as when I reinstalled the alternator last night the car ran like crap again. I was thinking of replacing the main lead from the battery +ve to the starter and from the starter to alternator anyway as I have burnt thru the one to the starter at any rate. I am still very suspisious about the wiring from the distributor to the amplifier under the coil as well.
I'll let you know what else develops as am getting a timing light and fuel pressure gauge to check other things later this week.

By the way when I am checking for the fuel pressure I have a gauge that I assume I connect to the vacuum tube from the regulator. What pressure reading should I be looking for if things are as they should be and what gauge wiring should be used from Battery to Starter and starter to alternator?

You read vacuum at a vacuum port. For pressure you need to connect either to a Scrader valve on the rail (tyre type valve) or fab a tee-piece into the pressure inlet to the fuel rail, ie the hose with the 9/16" nut on the back of the fuel rail.

Battery cables should be standard sizes as from an auto parts shop. You don't need huge cables as the battery is not far away. 2B&S cable should be right. For the alternator 8B&S should be adequate.

Thanks bee utey. Is it worth doing the vacuum test then on the regulator at least as since we had it reving ok last week end I would have expected any fuel pressure issues would have stopped that

If you tee a vacuum gauge between the reg and the manifold, you run the engine and pinch the hose to the manifold. If the vacuum drops while everything else is steady you have a leaking regulator. Normally fuel is then present in the hose to some extent.

As for the ignition wires, keep them at least 50mm away from the alternator and its wiring. During my Bosch ignition conversions I often clip the wires to the top radiator hose. Seems to work. And I know I talked about ignition timing earlier, make sure it is advanced by 6 degrees (before TDC) as I have seen people use the retard (afterTDC) side by mistake. Label the 6 degree before TDC mark on the pulley (to the right of TDC) with a white paint marker for clarity.