1987 B2 2.9 V6 fuel injector...

[tw205]

Have you ohms tested your coil. It’s an easy test and will eliminate the coil as the culprit. A bad coil is susceptible to temp changes.

 

[Nick1983M]

I have not ohm tested the coil. I had eliminated it from the issue once I noticed the fuel injectors were cutting out just as the coil was dropping voltage. How would I perform this test?

I also had suspected a bad wire or loose connection at the ignition switch. I noticed that once I got the new ignition switch installed, the dropping of the ignition seemed to have gotten worse. So I will go back today hopefully and mess with the harness connection

Thank you guys so much for the help!

 

[tw205]

I have not ohm tested the coil. I had eliminated it from the issue once I noticed the fuel injectors were cutting out just as the coil was dropping voltage. How would I perform this test?

I also had suspected a bad wire or loose connection at the ignition switch. I noticed that once I got the new ignition switch installed, the dropping of the ignition seemed to have gotten worse. So I will go back today hopefully and mess with the harness connection

Thank you guys so much for the help!

A multimeter is used to test the ohms resistance across both fields and then through entire coil. Sounds more difficult than it is. Google it will give you short videos or written instructions. Only takes 5 minutes.

 

[Nick1983M]

I messed around with that particular connector while I was replacing the ignition switch itself and didn't notice any changes. Did find a couple wires over by the hvac blower fan and repair those. Bypassed a few of the old fusible links. I'm wondering now, where are all of the negative wires grounded? I see on the wiring diagrams where several wires come to a grounding point, but where is this located?

 

[Nick1983M]

Or possibly a crank or cam sensor...?

 

[Nick1983M]

I'm doing continuity tests on wires from ecm to TFI module. Wire #4 from ecm going to tfi model won't ohm out. The diagram shows an IDM 22k resistor is this wire somewhere in between the two. Any ideas where?

 

[Uncle Gump]

Here is the rest of the ignition schematics.

If you can't get continuity on that wire... it's likely open.

 

[Nick1983M]

Well I'm partly retarded with the ohm meter. It was ohming 22.98k. So I'm still searching. Would the TFI module cause signal drop to dist and Injectors while idling?

 

[tw205]

I'm doing continuity tests on wires from ecm to TFI module. Wire #4 from ecm going to tfi model won't ohm out. The diagram shows an IDM 22k resistor is this wire somewhere in between the two. Any ideas where?

At the coil, follow the green wire into the loom. It will splice into two wires, one will go to resistor and one to tach.
Did you ever test (ohms) your coil?

 

[Nick1983M]

I hadn't yet. Should it test at a certain ohm?

 

[Nick1983M]

I do know the Tach will jump all over the place and freeze when ignition is dropped

 

[tw205]

I hadn't yet. Should it test at a certain ohm?

Yes. First disconnect the coil from everything. Ohms test from red wire pin to coil wire output to distributor. 8k to 12k should be a good reading. Now do the green wire, should be same. Now do from red to green, should be under 2 closer to 1.7.
These numbers are off the top of my head but close enough

 

[Nick1983M]

I got .3 from red to green. Everything else was in range

 

[tw205]

.3 I believe is a bad coil. That is not enough resistance. It’s been a while but I believe it should be 1.7. I’ll go check to make sure.

 

[tw205]

Everything I’m reading says that’s a bad coil or at the most borderline.

 

[tw205]

How to Test a Ford Ignition Coil

Testing the resistance across several terminals on your ignition coil is the only safe and accurate way to tell if the coils is damaged or not. Measuring the primary and secondary resistance requires an ohmmeter, and a digital readout is best if you have access to one. Most ignition coils will...

itstillruns.com

A quick link.
I went out and test 3 of mine in running trucks. All flutter between .7 and .8

 

[Nick1983M]

Sounds like I do have a weak coil. It's brand new which is part for my course haha.

It's seems as though I'm losing voltage at The red wired on the coil. It's starts to drop voltage, and then the green wire drops from around 58 volts to 28 volts (somes times less, some more) when this happens. I tested wires going to plug connector at injectors and losing exact same signal there, like someone is turning the key off dork a split second and back on, before it dies

 

[tw205]

I’m unsure on how that should work. I know to test for 12v at the red ( bat +) side with key on. Past that I’m unsure. A member over at therangerstation.com would be my go to. His screen name @RonD I think. You should post up over there as the rangers are virtually identical on most things.
Test your old coil, if it’s good put it back in.