How to hookup for RPM & Dwell (on/off ratio) readings

[Thai GI]

1. I purchase an automotive meter, noting fancy like the Fluke 88 or 199. It has the basic features like V, A, Ohm, Dwell and RPM.

2. My question is how do I hook up this unit to read RPM or Dwell (to check lambda)? The meter manual advised to put - side to ground and + on the coil's - going to the distributor for both options and also to check vehicle manual. Well the coil in our cars do not hookup this way. My applications are 87 190E 2.3 and 88 260E (California).

3. I’m guessing it’s at X11 but which pins to what?


Thanks in advance,
Thai GI sends…

[mctwin2kman]

For Dwell it is supposed to be Pin 4! For Lambda it is Pin 3! Let me know if it works as I have been trying every few months on my 190 but am too cheap to buy a new meter!! I have an old one I got off E-Bay for a few bucks but it does not seem to do much. I may be hooking up to the wrong spot since I have a 1986 and KE-II instead or your KE-III setup!

Connect the positive lead to pin 3 of the round diagnostic connector on the left fender well and the negative lead to ground.

Good luck,

[mctwin2kman]

Originally Posted by LarryBible

Connect the positive lead to pin 3 of the round diagnostic connector on the left fender well and the negative lead to ground.

Good luck,

That is for Lambda!!! What about Dwell???

Why do you want to check dwell? It is controlled by the EZL ignition module. It's not like you're changing points.

That asked, since this car has a somewhat conventional coil, you can go from ground to the + connection on the coil and should be able to measure dwell.

Good luck,

[mctwin2kman]

Originally Posted by LarryBible

Why do you want to check dwell? It is controlled by the EZL ignition module. It's not like you're changing points.

That asked, since this car has a somewhat conventional coil, you can go from ground to the + connection on the coil and should be able to measure dwell.

Good luck,

I stupidly long ago screwed with my Idle Air Control Valve! Which according to the Maint CD will affect Dwell Angle and change it on my 1986 2.3 8V motor. I just want to check it and get the IACV back to where it is supposed to be! Maybe I am not even thinking the right way!

[Thai GI]

Thanks for the reply

1. Yes, pin 4 is the RPM

2. Pin 3 is Lambda, actually I’m not looking to check “Dwell”. I’m doing the testing of Lambda control by using a suitable Dwell Meter in place of an On/Off Ratio Tester as the MB repair manual states.

Thai GI sends…