Perhaps a different tack.

What if your alternator is putting out only moderate voltage when it becomes heat soaked? Maybe just off spec enough to not allow proper functioning of certain ignition components.

The Lambda system will ruin a car's performance if the under seat relay is marginal or if the connection to the frequency valve is interrupted at the connection terminal to the right of the driver's rear shock top. On the fat cross brace that makes up the front of the engine "hole". In one thread a few years back a guy in Houston's car would run like crap in hot weather because that connection was marginal.

Perhaps when you rev it up it you re-establish the (or some) connection?

Test your battery voltage in that one minute period before it dies.

Replace the relay under the passenger seat. Even if not the issue, it's like a mini tune up. The contacts get tired and a new one works like it is supposed to. You will notice a difference.

Separate that connection by the rear shock and look at the terminals. Be careful as I bunged up the hold down tabs on mine from ham-handing it.

I am surprised that you have not purchased a dwell meter to check your AF ratio. You could also double check the consistency of the Lambda electrical operation with this tool.

Unless you have a ROW car, the dwell meter is the shizzle.

Hi Bob,

Interesting thoughts.

I already replaced the relay under the passenger seat at the beginning of all this. It made no difference.

I will take a look at the connector and see what it looks like.

The battery voltage reads almost 14 volts when the car is running normal. When it was stumbling today during my tests, the alt light came on just before it stalled. I think that's normal due to the RPM being at 400.

I would love to buy all these tools to properly test things out but unfortunately they are not cheap. I am getting there, slowly building up the tools in the garage.

Thanks for the input. I will let you know what I find.

G450X,

Sounds like your problem is exactly the same as mine and I do the same thing at stop lights. Hopefully we can solve the problem.

I'll buy that.

What I would like to confirm, if my car, would be if something weird happened to the voltage and THEN the idle starts dropping.

However, the alt light should come on if that happens, right?

Here is the dwell meter I have.

Actron Dwell Tach Volt Meter - Tools - Mechanics & Auto Tools - Diagnostic Tools & Testers

Yes, I would think the alt light would come on if that happened.

Wow, that Dwell Meter is cheap ;)

Thanks for the link.

In the background...Tony asked me to run a few simple tests.

With the FP running, I can feel the FV vibrating and hear it buzzing, so that's a good sign.

The WUR resistance cold is 25.9 ohms.

After starting the car up, I let it run until it stalled, then checked the WUR resistance again.

The WUR resistance after stalling is 9.7 ohms

Great on the FV.

I am working on an old Jaguar right now and all I know is that when warm, the sensors I have been checking always have significant reductions in resistance after they warm up as per design.

The bi-metallic strip is not a sensor though so I do not know if it should reduce in resistance so I performed some tests.

I have an old 089 that reads 31 ohms cold. I hooked a battery to it and put a laser thermometer on the green insulated coil wrapped around the strip. It read 150F when I tested the resistance. 31 ohms. I then put a heat gun to the strip and waited till I hit 200F. The WUR was hot. 31 ohms.

Not sure the low resistance is your problem, but I don't think it's supposed to drop off like that.

Bob,

I wasn't sure what it meant either. The entire process from 25.9 to 9.7 took about 2 minutes.

Tony can explain this much better than I. When I spoke to him last night, he said that's how he configured the WUR to operate. It's leaning out after 2 minutes of operation.

On a different note, I found a vacuum line capped off on the passenger side of my CIS. The PO disconnected the decel valve and capped off the line, but the decel valve was open. I thought this could have been my vacuum leak that is causing me problems. So, today I capped off the decel valve and ran the engine. Unfortunately, it didn't change a thing.

Let tony respond to this. I have a feeling the ohms drop is not right but I have been wrong plenty before.

Believe you are getting close.

You are comparing two different types of WUR.......
 

Bob K.

WUR--089 is for RoW '81-'83 SC with vacuum assisted and mono-resistance. WUR-090 is for USA '81-'83 SC non-vac assisted but with multi-resistance. You can not compare the performance of these 2 particular WUR's because they operate totally different from each other.

Since -089 is mono-resistance, the total resistance (Ohms) Rt is equal to R1. While the total resistance for -090 is 1/Rt = 1/R1 + 1/R2. When cold it should register at 25 - 26 Ohms and when warm 9 - 10 Ohms.

As you have demonstrated in your test, a mono or single resistance WUR will have basically one reading (theoretically). While a multiple resistance WUR would have a totally different reaction or result.

Tony

I did have fun performing the test, though. Thanks Tony.

Luo,

Did fixed your problem?, was the plugged vacuum line the problem?. I'm having the same issue .

Leo.

Subscribed. Having same problem for months here.

Leo and Tim,

Sorry to say, I never solved the problem. It is believed to be a small vacuum leak somewhere...

I'd fuel pressure test it to rule out anything there. Then you need to check for vacuum leaks. There's many threads where you can put some positive pressure into the intake system then spray some soapy water and look for bubbles. You can also spray carb cleaner around the CIS to find the bigger leaks.

My car would hunt and stall and I found big holes in the CIS boot, leaking injector seals, oil tank level sender seal was missing etc.

This past couple of weeks I dedicated my spare time to resolving this CIS warm restart idle issue that I have been having for years.

The first thing I found was the injector o-ring seal on cylinder six was so dried out it was causing a vacuum leak (well, the rest were very hard and dry as well). So, I decided to change not only all the o-ring seals but all the injectors too. Wasn't bad at all to replace.

After that, I took the car out for a test drive. The car ran much smoother with the new injectors but the warm restart issue was still there, however, the warm start issue was less.

So, I went off to read what other people have tried in this situation with some success and decided to replace my fuel accumulator and fuel filter. These changes were significant in the warm restart issue but the car had a rich running smell which was most likely caused by all these new components (changed all the dynamics). I then proceeded to adjust the fuel distributor plate using an allen wrench with a dwell meter connected to the test plug and also made a final adjustment to the idle with the throttle body screw.

At this point I said what the heck, I'll replace the spark plugs and time the car as well. BTW, the car was out of time as well. Once I re-timed the car, I did a few mixture adjustments again with good results.

The car now starts without issue cold or warm and idles properly at 950 rpm when warm without any surging whatsoever.

I know, you are not suppose to throw a bunch of parts at a problem, but I figured all these items were old anyway. Now at least I know what I have in there and a good baseline.

Lou, stop by and we can do a smoke test to check for any other air leaks. Takes 15 minutes.

Michael,

Are you around at all this weekend? If so, I will swing by.

Thanks!

Yes I am so send a text when you'd like to come over.