924Board.org

[Ian89C4]

Alright, these are kinda silly questions, but I am gonna ask anyways because for the life of me I can't find the answers...

Fist one and the most important, I think my EIS controller box is going on me, in my last race I was having issues with my ignition timing going all crazy after I bounced off of gators and trying to find the cars limits. After I carefully went through all of the electrics to include replacing the starter, I found that one of the pins in one of the connectors to the EIS box had been pushed in and was making intermittent contact, but jarred out of position when bumped, completely throwing my poor HALL sensor out of whack and losing ignition timing for a split second.

I still think that the box is having issues and as they are pricey and I am not worried about idle speed but maintaining timing throughout the power band, can I just connect the two connectors as it shows in the manual, or will this cause damage to the system?



The second question is the really silly one...what are the three temp senors on the hard coolant line in the pic for? I have never known this.



Cheers,

Ian
_________________
Ian Edgerly
North Carolina

Current:
1981 924 SCCA/ChampCar Weissach Race Car ("Serenity")
1987 924S ChampCar Endurance Car ("Der Weg")
1980 924 Euro ("Wahala")

[larchie]

[Ian89C4]

Awesome, thank you!

What does the coolant temp switch on the left control?

I am having warm up issues, I think she is ok through the power band, but just want her to be able to start better.

Right now I have to push the accelerator in a bit before she will start easily. Don't get me wrong, she will start, but it is pretty hard when cold.

Does anyone think it could be the coolant temp sensor? Either of them?

I am also going to check the ignition timing.

Cheers,

Ian
_________________
Ian Edgerly
North Carolina

Current:
1981 924 SCCA/ChampCar Weissach Race Car ("Serenity")
1987 924S ChampCar Endurance Car ("Der Weg")
1980 924 Euro ("Wahala")

[Rasta Monsta]

Only two CIS components are designed to react to temp: thermo-time switch for CSV firing and WUR for cold start enrichment.

If you are having cold start problems you can check cold control pressure, and check for voltage at the CSV on cold start.
_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[larchie]

So cold start problems are normally due to the cold control fuel pressure being incorrect. So as Rasta Monsta says check the cold control fuel pressure first.

The causes are usually as Rasta Monsta indicates the cold start valve does not open or the cold start valve is leaking. The cold start valve operates with the ignition in the "start" position and only if the thermo-time switch senses a cool enough engine temperature. It does not operate if the engine is warm. The thermo-time switch operates for about 8 seconds. It's in the extreme left corner of your second image in your post above. The blue/yellow wire should be going to your temperature sender unit -- the connection of which I can't see in the image.

Additionally, causes of cold start can include auxiliary air valve not opening, and the somewhat less likely causes of the warm-up regulator clogged screens or a faulty warm-up regulator heating coil, a vacuum leak, or even a sticky sensor plate or plunger when cold.

The Hanes Manual gives standard diagnostic tests for all of these, except maybe testing the resistance across the WUR's terminals which should not be zero or infinity but somewhere around 35 to 40 ohms. Also, a test for the thermo-time switch not in Hanes is to use an ohmmeter and if the stamped value on the switch is anywhere from 35 to 45 degrees C check the resistance from Terminal W to Ground. If the temperature is below 35 degrees F or so the resistance should be 0 ohms and if the temperature is above 70 degrees F or so the resistance should be roughly 110 to 160 ohms.

[Ian89C4]

Thanks guys for the responses!

I checked to see if the cold start injector was firing, it is not....so I have a few more things to run down. I am not too worries about it as she runs just fine one a little warmed up and even better once at operating temp.

I still have to toss the fuel pressure gauge / tester on there to see if the cold pressures and operating pressures are still within spec.

Cheers,

Ian
_________________
Ian Edgerly
North Carolina

Current:
1981 924 SCCA/ChampCar Weissach Race Car ("Serenity")
1987 924S ChampCar Endurance Car ("Der Weg")
1980 924 Euro ("Wahala")