Recent content by jcook100

@SenorNoob Any chance you could provide your feedback on this?

That is a good question. In fact, awhile back when I did the EEC-IV test, I did see a code pop up for the neutral safety switch. Take a look at these photos. I only see one switch that is "plugged in" - air quotes because it looks to be partially smashed and just barely connected. Is that the...

Well, I have an update, but not much good news. After working on this issue for months, I finally decided to take it to a mechanic in the area who has a lot of experience working on older cards. Long story short - he checked everything he could think of and spent many hours investigating, but...

Also, @RonD can you confirm that the 8-11v I should be seeing at the IAC valve with the engine running is with the red lead touching the red wire and the black lead touching the other wire (with it plugged in)? When I do this I see ~5v.

Yes. At first I tested with pins into the back of the connector, but then to make sure I stuck a pin in each of the two wires (red and white). This is with the connector plugged in. When I touch one lead to the wire and the other to a ground, I see voltage. This happened for BOTH wires. But when...

KOEO with the connector plugged in, red lead on red and black on other wire (using pins from behind) I am showing 0.02v. Engine idling at 1800 rpm.

Thanks, @RonD . For the first test, I am seeing 11.98v at the battery and 11.91v at the red wire of the connector (key on engine off). Is that close enough or different enough to be a problem? For the second test, with red lead on red wire of connector and black lead on the other wire (key on...

Okay, I may have found something. When I check the voltage coming out of the computer for the 21 pin, I am seeing 9-10v. When I check that same wire at the IAC valve connector, touching the other lead to a ground, I still see 9-10v. However, when I touch one lead to the "in" wire (is that the...

Does the voltage of ~5v passing through to the IAC valve seem about right?

I just don't get it because both are brand new, and this is the second brand new IAC valve I have tried (and it is Motorcraft).

Thanks @rubydist, I will take a look. @RonD what would you try next?

Welp. I replaced the ECM and it did not resolve the issue. Idle is still around 2000 rpm and drops to 900 when the IAC valve is unplugged. To review: no vacuum leaks, new PCV valve, new IAC valve (Motorcraft brand), and new ECM (computer). I even tried unplugging the battery for a few hours...

I ended up ordering a rebuilt ECM for about $150, with a $45 core. I figured it was worth $100 or so to just swap it out. It is on the way. In the meantime, I was able to do the EEC-IV test. For Key On Engine Off (KOEO), I received two codes at first: 24 and 67. After a couple of repetitions...

Update - I will try the EEC- IV system that @franklin2 mentions up above.

Okay, thanks. Is there anyway to test the computer while it is in the car, just to confirm that that is where the issue is? For instance, would it throw a code, and if so, how would that manifest on the dash - the check engine light?