When measuring the crank angle sensor resistance on my 86 S4, the resistance on both triggers is 230 ohms.

The FSM says it should be 110 to 210 Ohms. . . . .In this situation, does being off by 20 ohms seem reasonable?

I've got a rough idle and I'm looking for reasons that could cause that. . . .. There are several on this car, but this is the latest out of spec thing I found.

I would think the resistance would be ok as the important thing would be the timing of the trigger with relation to the bottom gear.. . . .Anybody wanna donate their two cents?

I'm gonna time it next and see what happens.

Thanks. . .RL

 

That out-of-spec resistance might be due to the electrical connector on the CAS. Those wires in the connector are crimped and after 35 years I'm sure they have corroded which is contributing to your high resistance. Maybe try cleaning the connector with spray cleaner with something like DeoxIT D5 or replace the connectors or buy a new CAS.

 

its within 10% of the spec, you're ok. cleaning the connector and making sure it makes good connections is not a bad idea

 

That's what I thought too. The ECU is looking for a pulse. . ..I don't think it's a situation where ohmage effects volts return.

My major problem is a rough idle. . .. .. The car runs smooth at higher RPMS.

Once I get the car started it will go to 3,00 rpms till warm.

I'll time it anyways, but I'm gonna cross the crank angle sensor off the list of possible causes.

I'm down to fouled leading injectors, (cars been sitting for a few years), or a leak at the EGR gasket. Either way, it looks like I'm in it for a Intake removal.