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View Full Version : how to check RPM with no tach?



dude
03-14-2016, 09:04 PM
Hello,

I would like to check my idle rpm, sounds high by ear. Supposed to be 750rpm. My 1984 Auto 2WD van has no tach on the dash. I do have an rpm/dwell meter which normally would connect between ground and the coil however as you know in this distributor design the coil is not accessible when operating. Consulting the field manual shows a special test connector on the drivers side of the engine I believe. I cannot find this test connector. Is it with the other check engine connectors? Any ideas on where/how to check rpm would be greatly appreciated.

By the way, I believe I have some type of issue as I've had to adjust my throttle body idle adjust screw ALL the way in. Van runs good but idle seems high, not excessively high but again I cant read rpms, I've checked for vacuum leaks and haven't found anything obvious to me. Now when I disconnect the vacuum line directly from the air intake below the throttle body before the Tee in the vacuum line and transition to tubing I get a nice drop in idle rpm. Any ideas?

thank you very much!

timsrv
03-15-2016, 07:46 PM
You'll need to hook up your tachometer to do accurately set timing. There's a search feature on every forum page (upper right). I typed in "tachometer" and found this right away:

http://www.toyotavantech.com/forum/showthread.php?752-New-guy-wanting-to-say-H-i-and-a-tachometer-question

dude
03-15-2016, 08:45 PM
You'll need to hook up your tachometer to do accurately set timing. There's a search feature on every forum page (upper right). I typed in "tachometer" and found this right away:

http://www.toyotavantech.com/forum/showthread.php?752-New-guy-wanting-to-say-H-i-and-a-tachometer-question

Thanks, I was searching under idle and rpm. That is what I needed.
Since I'm just tuning and don't need a permanent tach I also went ahead and got an inductive meter from Harbor Freight Tools for $35 bucks.

http://www.harborfreight.com/lcd-automotive-multimeter-with-tachometer-kit-95670.html

Its a multimeter also comes with a temperature probe and a nice plastic case so it's not a bad deal. I clamped the inductive pickup on to the Cyl 1 spark plug wire and was getting about 700 to 800 rpms so i'm good. Thanks!