Junk the permajunk.... Gunter had a CDI for sale, rather inexpensively. I would check with him (darn, I never saved up the extra cash to buy that one!!!)

Carmona is in East Texas. Uhm, make that WAS in East Texas. Near the old 7/11 store seven miles from Corrigan and 11 miles from Woodlake. Actually, I think the store had finally caved in last time I was through there about four years ago. I have family buried in the cemetary there, not much else left of the town. One house a family member lived in until the late '60s was still standing in Woodlake at that time. The other house (abandoned ~ five years ago) had fallen down in rot and the main house was raised in the early '50s.

Just asking, I have close family roots in deep East Texas, Piney Woods. Basically either poor white trash or well off land owners, most of whom from both backgrounds are all dead now. We didn't reproduce much.

Saturday update.

I got the car nice and warm and to a point where the problem kicked in, I then stopped the car and unplugged the two sensors on the chain housings, no whurring sound and the car had the problem.

Thinking about it logically after-wards, I am sure that they are not the problem, as it is the OUTPUT from the lambda computer to the frequency valve that is being cut and the frequency valve not moving (Is this the same as the default 50% duty cycle? I suspect not).

I think maybe the next step is to connect a dwell meter to the test ports when the engine is working correctly and see what the duty cycle is and the connect again when I have the problem and see what it is.

Slight tangent question, if I pull the 02 relay and richen up the mixture, would this make the car usable?

Hi Jim,

You can pull the O2 sensor and get the car to where it runs real good but i think the juice needs to be going to the freq valve. That is only my assumption. I just don't know what happens when the juice is cut to the frequency valve like with your problem.

I do (first hand) know that the Permatune is not reliable. My symptoms were (both boxes) instant death of the car - 1/2 hour or so cool down, then would work again.

I have done loads of research today whilst I wait for a friend to bring a dwell meter to work tomorrow and I think that I will have the answer tomorrow evening. I suspect that one of two things will happen:

1) I will test the system using the dwell meter when it gets into the closed loop phase and note the duty cycle, I will then warm up the car until the problem occours and measure again, if I get a signal then the frequency valve is bad

2) if I dont get a signal then the lambda computor is bad.

It could of course be the wiring in between the two but this is now proving to be such a reliable fault that I think it is component based.

Permatune was all I could get when my Bosch box went bad, its proved reliable so far but I have heard all the bad stories so it's just a matter of time I am sure.

Spent some time today thinking about converting to carbs or designing an EFI system, what do you think?

I have connected the dwell meter and I showed around a 45 deg duty cycle when the engine was running ok and a 40 deg cycle when the engine had the problem, this means I am going to focus on the frequency valve as it would appear that the lambda computor is working as it should.

next step will be to measure the dwell (At least I assume it will be dwell) actually at the frequency valve itself.

Any ideas or info greatfully accepted!!

I have found the problem!!!!!!

I have dropped the engine slightly to get more access to check the input to the frequency valve, I removed the heater hoses and blower to get more access "around the corner" in case I needed to use both hands.

On doing so I spotted the rear disconect for the engine harness, its; a plug about 11/2 inches long, just for completeness I jumpered the relay again, no whurring, I shook the plug.....Whurring!! I moved the plug arond and by moving it I could go from whurring to not.

I pulled the plug apart and found loose and corroded connections, I am not sure that some of them are rescuable so I might have to do a temporary fix until I next drop the engine, access is pretty restricted in that area.

More tomorrow when I have accomplished the fix.

Glad to hear you found the problem. I have been watching this progress with interest as I am slowly tuning up my recently installed engine. I installed an 82 into a 78 chassis, so I had to install a lambda and harness - Previous setup was without O2 sensor installed, so I am sure the engine was "tuned" to compensate. My engine starts quick, sputters for 15-20 seconds, and is hesitant for the first minute or so, then, once warm, pulls hard and smooth. So, this upcoming weekend I hope to get some garage time in and start checking the same areas that you have been focusing on (although I am sure my connector is ok as I did check that before I installed knowing it would be a bear to get to after the fact.)

Great job on trouble shooting. You would have finally found it through this last test once you disconnected the freq valve and tested continuity.

For fun - Check the multi-pin connection back in the corner of the driver's side. It is the same build as the one on the firewall where the freq valve issue was. If moisture caused your current problem perhaps gremlins are inside this one as well.

Well it looks like its fixed, I had to use "bullet" style connectors that I had over from when I built the loom for my rally car (See my garage). I then covered each individual connector with heatshrink. I then "p" clipped the engine side of the loom to the original connector location to take the strain off of the new connectors.

Took the car for a good drive and got it quite warm although the temperature here in Dallas has dropped into the 90's so it didn't get as warm as it has been doing, no problems to report.

Mycastle, not sure your problem is the same as mine , but you might want to check out the low set temperature switch to see if its giving the lambda computor a signal, if not the computor will be relying on the signal from the 02 sensor which wont have warmed up yet.

Overall I have learned loads and made a new friend, thanks Bob Kontak for all your help and encouragement, this would have been so much more difficult without your help. Let me know if you are ever my way, I have a cold one with your name on it.

I will change out the 02 sensor this weekend just to complete the exercise.

Wednesday update,

Drove the car to work and back today without issues, admitedly the OAT was much lower but the car ran better than it has done for some while.......funny how you don't notice it getting slowly worse isn't it.

Still planning the 02 sensor change.

Jim - Good thread, any updates since last wednesday. Connector condition was deemed as your core problem correct?

I bought the new 02 sensor on Sunday and have yet to fit it, but the car has run without fault since I re-did the connector.

I was also having issues with hot starting, I had already replaced the fuel pump check valve and the accumulator last year for the same issue. This time I ran a can of injector cleaner through it and that is also now fixed, I suspect a clogged injector staying open and bleeding the fuel pressure away.

Third issue was that when hot, the engine was very slow coming back down to idle, I currently have the vacuum pipe to the decel valve disconnected and pluged, this has fixed the slow to return to idle issue, if anything the engine is now too fast at getting there making smooth gear changing difficult.......I will work on that one.

I will replace the 02 sensor this weekend ($17.99 from Pep Boys) and will report back.

Bob Kontak and I have talked about doing a definitive guide to the lambda system on the CIS, do you think that it would be popular?

I think it would be very popular yes.

I have a 78SC ROW with no 02/smog/lambda, so not applicable to me, but would still be helpful to others, yes.

Final update on this thread.

I changed the 02 sensor at the weekend and I have run the car to work and back for two days now without problem, I have not seen a discernable difference in the car since I changed the sensor which leaves me to think the other one was working correctly.

Final conclusion is that rewiring the rear engine disconnect plug has fixed the problem.

Now I will go and work on the troubleshooting guide.

Jim,
you have a pic link or diagram of what plug youre talking about?

thanks (and congrats on your troubleshooting)

I have been trying to find a picture using the haynes and bentley manuals but so far have been unsucessful.

The plug is located on the rear bulkhead in between the shock towers, there is a metal "channel" welded to the bulkhead and there is a mounting feature on the plug that allows it to be slid into place.