I'm about to buy a decent auto multimeter I can use for timing and dwell angle on the A series and also for all the measurements I need to do for the CA18DET installation.

I've been looking at this one.
http://www.tandy.com.au/cgi-bin/tandy.storefront/44ff6e270066b7f02741c0a87f9c0745/Product/View/Q1585




I am interested if anyone has a better suggestion? (as my experience with this stuff is pretty liimited).

There is this one too....doesn't seem to do as much though.
http://www.jaycar.com.au/productView.asp?ID=QM1440&CATID=&keywords=qm1440&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

any multimeter is handy and would be sufficient to wire up an engine swap, but one with automotive functions will help in ways that a standard one can't.

I was just unsure if I can get something useful in this price range ($50 ish) or if they just weren't worth it....

I also want to make sure I have all the functions I'll need (some I wont even know I'll need until something doesn't work on the motor)

I can't seem to see much else worth looking at after $80 until I get to around $500....

For the CA you won't need to check timing or dwell angle...come to think of it, if you convert to electronic ignition, you don't need it for your A-series either. Static timing can be checked without a meter. Dwell is only checked with points ignition. Dynamic timing is best checked by listening for pinging (not using a timing light).

Here's what I would look for:
- low RPM readout (0-2000 rpm for setting carb)
- voltmeter with 20 m-ohm input resistance so you can directly read oxygen sensor output. Tandy used to sell a voltmeter like this for $20.
[edit: people are now saying 10 Mohm input resistance is OK (including one sensor manufacturer). Most of the Tandy units can do this]
- DC voltmeter for checking alternator output
- AC voltmeter for checking electric outlets for when your tools and appliances stop working
- ohmmeter with audible continuity sound for checking circuits

Usually you can get Dwell + RPM in one tool for $30 USD or so (like at Sears).
It's not pretty, but it does the job.

Another useful thing is to measure sparkplug wire resistance (leads should less than 1kohm/foot). Any multimeter should do this.

check out what you can get from snap on, i know the name is synonimus with mega bucks, but i bought an automotive meter of my snap on guy and it really wasnt all that expensive.
and an audible continuity buzzer is a definite must, it is just about the handiest feature on a multimeter.

Is frequency useful at all? I thought for PWM type outputs it might be handy?

# FREQUENCY
# Ranges: 320Hz, 3200Hz, 32kHz
# Resolution: 0.1Hz
# Accuracy: +⁄-(1.0%rdg+4 dgts) on all ranges

Checked out SnapOn too....didn't seem to be any automotive multimeter under $300.

At the moment I'm keen on dwell (for the A14 Datsun) and like the idea of the RPM functions (to set idle).

The mystery of the CA drives me to want more...

Here's the specs on the Tandy one....I don't understand for sure what input resistance is. Is that the innate resistance present in the multimeter (which could slightly effect results) or are you saying that the device needs to measure resistance at at 10Mohm scale?

* For DIY Car Maintenance
* RPM Measurement for automotive engines with 1 to 8 cylinders using the supplied inductive clamp.
* Auto Ranging with manual ranging override
* Large 3260 count LCD screen with Bargraph and Function indicator
* Data and Range Hold function
* 13 Functions include DCV, ACV, DCA, ACA, Resistance, RPM(Tach), Dwell angle, Duty Cycle, Frequency, Temperature, Continuity and Diode test
* Fused current inputs and overload protection on all ranges
* Complete with Rubber holster, test leads, Temperature probe, Inductive Pick up and 9V battery
* SPECIFICATIONS
* RPM(Tach)
* Ranges(RPM4): 600-3200, 6000-12000(x10RPM)
* Range(RPM2⁄DIS): 300-3200,3000-6000(x10RPM)
* Resolution: 0⁄1%, Accuracy +⁄-2%rdg +5dgts
* Overload protection: 500VDC or RMS AC
* DUTY CYCLE
* Range: 1.0%-90.0%
* Resolution: 0.1%
* Pulse width: >100us<100ms
* DWELL ANGLE
* No of Cylinders: 2, 3, 4, 5, 6, 8
* Ranges(Degrees): 0-180(2Cyl), 0-120(3Cyl), 0-90(4Cyl), 0-72(5Cyl), 0-60(6Cyl), 0-45(8Cyl)
* Temperature: -20 Degrees Celsius to 320 Degrees Celsius
* DC Voltage
* Range: 32mV, 3.2V, 32V, 320V, 1000V
* Resolution: 100uV
* Accuracy: +⁄-1.2%rdg + 1dgt
* Input Impedance: 10MOhm
* AC Voltage
* Range: 3.2V, 32V, 320V, 750V
* Resolution: 1mV
* Accuracy: +⁄-2.0%rdg + 4dgts at 50Hz to 60Hz
* Input Impedance: 10MOhm
* CURRENT
* Range: 320uA, 3200uA, 32mA, 320mA, 10A
* Resolution: 0.1uA
* DC Accuracy:
* +⁄-(2.0%rdg+1dgt)on uA and mA ranges
* +⁄-(3.0%rdg+3dgts)on 10A range
* AC Accuracy:
* +⁄-(2.5%rdg+4dgts)on uA and mA ranges
* +⁄-(3.5%rdg+4dgts)on 10A range
* Frequency response: 50Hz to 60Hz
* Voltage Burden: 0.2V on 320uA & 32mA ranges; 2V on 3200uA & 320mA ranges
* RESISTANCE
* Ranges: 320 Ohm, 3.2Ohm, 32KOhm, 3.2MOhm, 32MOhm
* Resolution: 100mOhm
* Accuracy:
* +⁄-(1.5%rdg+3dgts)on 320Ohm to 320KOhm ranges
* +⁄-(2.5%rdg+3dgts)on 3.20MOhm
* +⁄-(5.0%rdg+5dgts)on 32MOhm
* FREQUENCY
* Ranges: 320Hz, 3200Hz, 32kHz
* Resolution: 0.1Hz
* Accuracy: +⁄-(1.0%rdg+4 dgts) on all ranges

http://www.tandy.com.au/cgi-bin/tandy.storefront/en/product/Q1585

That seems like a nice one. It does Dwell, Tach, and Input Impedance: 10MOhm. Plus all the regular voltage, ohmmeter, etc.


The Input Impedance is related to measuring voltage. 10Mohm is very high, it is good.

An oxygen sensor generates a voltage which you can measure to see if it is working correctly. However it generates a very weak current. If you try to measure it with a standard voltmeter, the slight "load" the voltmeter circuitry puts on the sensor will cause the voltage to change and give a false reading. What you want is a voltmeter that has practically no effect on the circuit being tested. That's what 10Mohm input impedance will do. At least that's my understanding.

I have tested several Oxygen sensors this way. You can tell if they are bad sometimes. A working sensor will slowly fluctuate over about 1/2 volt range. If it stays steady something is wrong.

Ahh that's good news.....consider it purchased! $AUS79.99.

Comes with an inductive pickup too!