I have a CMC widebody and the fuel gauge is off by a quarter tank and the speed is off by 5 mph. So, I would like to know how I can test the engine to see if my tach is correct. help please?
PS: I handy and can follow instructions, however I am new at cars and motors.
Thanks
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I have an old meter that is for cars and measures Dwell, spark plug resistance and tach - it for doing tune up in the 70-80's. Suspect they still make them - one below for $25. You could buy a cheap $20 tach from auto store too - or find a backup gauge. It's a simple 2 wire hookup.
Take it to a local mechanic and ask if he could put a portable tachometer on it to see how it compares to the one in the dash. I would trust mechanics tachs from Sun, Snap-on or Craftsman (which used to be built by Schlumberger) but bear in mind that most of them may vary by 1%-5%.
Alternatively, most higher-end portable timing lights have a tach built into them as well and you get to keep the tool for the future in your garage.
Ok I have been the meter picture below, however I do not know how to use it !!
1) a) in the first picture what is the metal thing on the lower right of the picture for ...and..... do I have to use it... and...... where does it go??????
b) in the first picture where do I connect the "RED" clamp to and where does the "BLACK" clamp get connected?????????
2) In picture 2, where do I set the left "RED" switch to ???? where is the black knob in the middle get set to "high RPM" or "low RPM"...
the right "RED" switch I shall set to 4 cylinders
Red lead to the distributor side of the coil (follow the wire from the distributor to the coil), black alligator clip to a good ground, set the selector to "tach" and "4-cyl". Make sure you read from the "4-cylinder" scale on the gauge for the tach rpms.
That third connection looks like it goes on the battery to show you "amps" draw under different operation conditions. Typically, that function is often useless unless you have a calibrated load (a big, honkin resistor) in Series with the gauge ( you don't) So just wrap a rag around it while you're testing with the other leads.
Thank you for all help. One last question
In picture 2, where do I set the the black knob in the middle get set to "high RPM" or "low RPM"...and what is the difference?
Can't read dial on your meter - but there should be two RPM scale markings - one to zero maybe 2/2.5k and other maybe 2k up to maybe 8k. So if checking idle - use low and if top end (5k-ish) use high.
You know.....Life is eerie at times.
I'm renovating my garage with new (to me) kitchen cabinets and I had to get everything out of there to install the new stuff.
In the process of that, yesterday I moved an old cabinet which holds my test gauges and found my old Craftsman Dwell/tach meter. I probably haven't used that thing in 30 years and it pops up now.......
Think I'll put it on Pearl and see how close the two tachs (portable and dash) relate.
Mine is Craftsman too - still in cardboard box. Funny how days of "a tuneup" are gone but folks still call it a "tuneup" when its really just replace plugs at 60 or 100k! I wanted to adjust valves on Toyota and you had to buy an assortment of shims to do it.
Wow....
The last Toyota I had to adjust the valves on was an 18TC engine with twin cams that I bought from a US Airforce guy who brought it back from Japan with him to Connecticut. A decent valve adjustment took the better part of an afternoon, but would that thing ever scream! I gave up playing with Datsun 510's and spent a lot of time totally surprising Mustang and Camarro riders.
ahhh....the 1970's, relived!
