Injector resistance value?

bowlsby · 01-28-2001, 03:40 PM

What is the resistance value of the 1974 914 2.0 (green) fuel injectors? I have a GA code engine.

I researched every source available to me and various sources saide 2.3 ohms, 2.4 ohms, 2.5 ohms and one even said 2,400 ohms.

When I measured my injectors cold I get 11.4 to 11.8 ohms at about 55 degrees ambient air temp. The digital voltmeter jumped around alot, but finally stabilized at those values...are the values variable as temperature changes?

My car works fine, I just need to know the accurate value.

bowlsby · 01-28-2001, 05:21 PM

Update...it gets weirder...

The previously posted values were taken from the ECU connector through the FI harness.

I measured directly at the injectors and the two I measured are exactly 3.2 ohms each.

I suspect that the factory value is 2.4 ohms, but can anyone verify that?

Is there a tolerance range on the values (i.e. are they within factory spec between 2-4 ohms) or is the required value exactly 2.4 ohms? What difference would it make, if the injectors fire when told to?

Would there be any reason that the value would vary with age, temperature or ???

TimW · 01-30-2001, 07:11 AM

Sorry I don't have a factory manual to look up the tolerance range, but I'd be happy to check the resistance of my injectors if it would help. I have the engine out right now, so it would be no trouble...although I do need to get some new batteries for my multi-meter

.

Update: My GREEN injectors from my '74 2.0L motor are: 2.4, 2.4, 2.4, and 2.3 ohms @50ish degrees, maybe colder?

[This message has been edited by TimW (edited 01-30-2001).]

[This message has been edited by TimW (edited 01-30-2001).]

bowlsby · 02-01-2001, 02:15 PM

Really interesting. Thanks for the actual values.

I have checked the resistance of various FI components through the FI harness (at the ECU connector block) and then directly at individual components. I discovered that the harness wiring adds about 1-4 ohms of resistance to each wire connection. Maybe not a big deal with large resistance components like the pressure sensor (90 and 350 ohms) but what about the injectors? If they are supposed to be 2.4 ohms and the ECU sees a 4-5 ohm load...I think it would effect the system in a negativve way.

Any comments?