Blue44

Hmm, audi marv I have nothing close to 1.0 ohm of resistance unless you mean 1000 ohms; which I doubt you meant.

For communicating the pins which show resistance I will explain that if you're looking at the sensor connector for tach and crank and have the center plastic single groove at the top. The first terminal at the left would be terminal "A" then "B" and "C" as you look to the right.

I tested all the terminals between eachother for resistance and found that only terminals "A" and "B" conduct with the ohm meter. Every other configuration is an open circuit and has no conductivity.

For the crank ignition sensor between "A" and "B":

920 ohms of resistance (checked multiple times - always the same reading)

For the tach/rpm sensor between "A" and "B":

955 ohms of resistance (checked multiple times - always the same reading)

I made sure and double checked if I was reading mega or kila ohms or if I had a decimal point showing on my Fluke meter. These readings are correct.

Should I assume that both sensors are way out of wack and have way too much resistance?

The RPM and spark functioned yesturday until the car got warm.

Any thoughts much appriciated.

jurq

Have you pulled codes from the ecu when the car dies (without turning the ignition 'off'? That will at least give you some leads. How is your alternator running? Battery? Ignition switch?

Just some other thoughts.

HTH,
Jim

Blue44

Thank you Jurq, I have not pulled codes. I was told that this does not show up on the flash codes. But pulling codes is worth a try! I have a good working alternator, battery, and an ignition switch which needs a litte tilting up with the key for crank position to engage. I am currently using an exterior starter switch button hooked up to the starter signal wire and the + terminal under the hood infront of the fuel distributor.

Thanks for your thoughts. For the sake of piece of mind I am going to install a new ignition switch which I purchased a few days ago. I have only had the car for ten days now.

yodasfro

Both crank sensors should be 1000 ohms + or - Test between pins 1 and 2.
If this happening only when warm I'd suspect one or both crank sensors.
The rpm sensor is what tells the fuel pump to turn on, then the ECU must get signal from the ign. reference sensor and the hall sensor to send spark.
The crank sensors are known to fail from heat on the v8's as the exhaust is right there. But that isn't the case with a 10v. I would think at this point the hall sensor in the distributor is suspect. Like Jim said pull the codes.
Is it MC1 or MC2? If it's the later the fault codes are stored until you erase them.

audi_marv

Based on your numbers I would think that both of your sensors are suspect. Sorry....reading should be 1k ohm for the sensors. I once had a sensor that read 096, and it turned out to be bad. Pulling codes should verify if sensors are bad, along with hall sender.

Also, when you swapped the sensors at the bell housing....did you also swap the corresponding connectors ?

Blue44

Thank you gents! I have found the problem! The car now runs fabulously!



Problem: The is a two pin connector that plugs into what looks to be a voltage regulator style device (maybe a capacitator) right next to the ignition coil. This connector had a bent electrical prong terminal inside the connector. It was not secure on the device enough. I figure when the car got warm enough under the hood the connector housing flexed and the circuit lost its connection. I bent the electrical connection back to normal and the car now runs perfectly with no loss of spark ever. I'm so glad it was this easy. Thanks for your time!

In the diagnosing I did pull engine codes and found none. It was a long extensive ordeal to get the engine light bulb to work since the bulbs I had were old and flaky. I decided to retro fit a circuit with the check engine light using a 13ohm resistor in parallel with a 464ohm resistor and an LED bulb. My check engine light should not fail with this new bulb. I do not recommend doing this however if you simply put a resistor in place of the bulb(with another circuit for the low amperage LED). The resistor gets too hot to the touch within 3 seconds. I recommend running many resistors in parallel to take the roughly 1 amp current. My car has this 13 ohm resistor in it now but I plan to change it because I'm sure it will eventually create a problem/magic smoke!

Thanks again!

Blue44