Awesome, I'll be taking the car for a drive tonight anyway (not my DD) so I'll take this FLUKE DMM home and test that. I'll also get the part # off of the CCU. NO, I didn't try running a test wire to bypass the switch since it seemed like the switch and wiring checked out, I can do that tonight too though.

 

One other thing. Near the Trail coils is a black bullet connector with a Yellow/Blue wire. If you put the neg lead of the meter on a good gnd and then the positive lead into that bullet with the Yellow/Blue wire, and the meter on dcvotls, them press the HZ button, you should be reading accurate RPM. You could compare that with your tach in the combination meter cluster. Using the black bullet near the Leac coil assy will give faulty readings, so don't bother.

Gone for the day. No reply needed.

 

OK... I checked the frequency on the Green/Red (Speed Sw) Wire. I got about 22hz at 20mph and it did not climb on it's own.

I ran a test lead on the Green/Orange (SET) wire and grounded it momentarily at 40mph... same result, the car accelerates.

I couldn't find a black barel connector at the trailing coil.. there is a white one there, I got about 28hz on it at about 800rpm. There is a black barrel connector at the Leading coil but I didn't fool with it.

I set the cruise on the highway at 55Mph and let it climb almost all the way to 90 before I hit the brake.

I checked the CCU for a # and the original one I pulled is almost illegible but it looks like it says FB01A.... BOTH of the new ones I'm testing with are FB44 (we may have just hit paydirt here. I was under the impression that all S4 cruise computers were created equally but... perhaps I've been misled.

Thoughts?

 

I'm so lost... I did a search for FB44 and found this thread:

https://www.rx7club.com/showthread.p...highlight=FB44

Now, at the end of the thread Hozzman says the TII CCU is marked FBO1A but your post says FB01A is the N/A and FB44 is the Turbo. Also, there's no clarification wether or not they are interchangeable. I'll PM the guy I got these from and see what actuators are on the cars they came out of...

 

I didn't do anything today related to this problem.

MAYBE tomorrow. What I'll do is look at the 86na that has vacuum assist, and compare numbers on the CCU with my turbo cars that have the electric assist. Maybe swap the CCU's out b/t them and see what happens.

I do remember getting myself and others confused on this. My 87 was a na with vacuum assist, and since I've put the electric assist in it. I flat forget the CCU's numbers and if I had to swap them out also. Your problem MIGHT lie there.

It shouldn't cause me much trouble since the CCU in the 86 is just hanging there and bumping against my foot as I went to work. By the way, the plug on that sucker is a pisser for me to get off for one reason or the other. Whine.

 

hehe, mine sticks in there good and tight too. here's an E cookie. Thanks for the help man.

 

The online parts fische says W/O Turbo: FB01-66-320A.

TURBO: FB44-66-320

I find this info in the parts fische, BODY section, Page 2-H16

Ummm. Cookie good.

 

That's your problem. I put the FB44 out of my turbo car into the 86na car and sure enough, when SET, that sucker keeps on a climbing right up to the stars. You need the FB-01.

There might be a way to wire around this at the actuator. The circuit in the CCU and switch seem the same b/t turbo and non turbo. IT's at the actuator things get different. That's from a fairly quick look the other day.

 

excellent, I have the guy that supplied the CCU's sending me an FBO1 CCU and an electric actuator to test out. Thanks again man, your my cruise control hero.

 

Well, try the FB01 with your present vacuum assist first.

The FB44 is for the electric actuator. When I put the FB44 in the non turbo car with vacuum actuator, the speed kept climbing. Which means to me the FBO1 is the one that should work with the vacuum assist.

Then again you have a FB44 , and the fellow is sending you an electric actuator, so THAT combination should work.

 

Mine did the exact same thing. I swapped out the actual cruise switch and it works perfect.

 

I think you probably had a stuck set button, it's a common issue.

 

Follow up:

Got an electric actuator in to go with the FB44 CCU... TADA!! working cruise! sweeet.

 

Sounds like you've a few n/a cruise parts laying around now. Selling any of it?

 

Most of it is going back to the guy who sent it to me. He was gracious enough to send me any parts I need and trust that I will pay him for what I use and send back the rest. I do have a complete S5 N/A cruise kit that's BRAND NEW save for the actuator (tested and working used). I have a second tested and working N/A actuator and a tested, working S4 switch that has broken mounting tabs. I also have a S4 N/A actuator that's untested and a S4 N/A CCU that does not work.. I don't know if they're rebuildable or not.

The parts in the S5 kit are listed at the bottom of the page here:

https://www.rx7club.com/showthread.p...56#post7252056