Thread: Injector Ohms
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Old 07-26-2009, 08:10 PM
olddog olddog is offline
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Join Date: May 2006
Location: St. Louisville, Oh
Cobra Make, Engine: A&C 67 427 cobra SB
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Default Injector Ohms

I suspect I may have an injector coil breaking down and shorting out when hot. I took the following measurements with the engine at normal operating temp. It was running fine when shut off. The column that says "coil" is measured across the injector coils two pins in ohms. The 3rd column "coil to ground" was measure with the meter red lead to valve cover stud and black lead to injector coil. I got the same reading to either side of coil. This column is in Meg Ohms.

Now what amazed me is that if I put the black meter lead to the stud and the red meter lead to the injector coil I get a reading about 6 Meg Ohms higher than the other way. Typically I never pay no mind when measuring ohms. It is not an el cheapo meter. This is a Fluke 70 III digital multi meter.


cylinder .. coil ...... coil - gnd
1 ......... 12.6 ......... 3.5
2 ......... 13.0 ......... 8.3
3 ......... 12.8 ......... 5.5
4 ......... 12.7 ......... 8.5
5 ......... 13.1 ......... 8.2
6 ......... 13.0 ......... 14.2
7 ......... 13.0 ......... 9.3
8 ......... 12.9 ......... 8.1


I went back out and re-check the ground to coil measurement, maybe 30 minutes after I took the first readings. Then the #6 injector reads open from the coil to gound and the rest are reading 15-25 Meg Ohms.

Your thoughts?
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