Car died twice this week

[ahlem]

I'm looking for insight as I look for the cause of my car's dying habit.
The first occurance happened after it sat for 10 days and was a bit hard to start. It had rained heavily twice while I was on vacation.
I was driving at 45mph about 2 miles from home and came up to a stop light and the motor died at idle and wouldn't start. I thought I figured out the problem when the coil wire terminal was corroded inside the cap to the point that it broke off when I was checking for spark and tried to remove it.
I put on the spare cap, rotor and coil wire from the parts collection and all was good. 4 days later, I was 4 miles from home running on the freeway and came up to the top of an off ramp and the same thing happened. I sat there 15 minutes or so trying to start occasionally and finally it just started up like nothing was wrong.
It idled for a couple minutes but when I went to take off, it died.
I will check fuel pressure tomorrow. What relay controls the fuel pump? It's fuse #23 15 amps and the fuse id good.
Suggestions for other items to look at would be welcomed. CPS maybe?
The car has 416000 miles so everything is suspect. Up until now it has been very reliable, just routine maintenance stuff.

[shogun]

CPS maybe, should be 540 Ohm +/- 10 Ohm between Pin 1 and 2, see here the pics http://www.e32-schrauber.de/bmw/s-kw-sensor.htm
Fuel pump relay you can find in the drawings of the ETM http://shark.armchair.mb.ca/~dave/BMW/e34/

[Bill R.]

Its most likely k201 or k202 either one will cause it. https://www.bmwtis.com/etm/data/e34/1990e34/1990e347100_0-00.pdf
Main relay or fuel pump relay.

[ahlem]

So I finally got some time to start diagnosing the issue. I started the car in the driveway and it ran just fine for about 5 minutes then just died. I put a spark tester on the coil wire and cranked it and no spark. I did a stomp test and got 1444, no codes. It's a 1990 m30b35 motor. There are two connectors just next to the Fuel Pressure Regulator. I wiggled the Crank Position Sensor wire and tracked it to the rearward of the two connectors. These are mirror images of each other. Is the front one for a cam position sensor? I checked the resistance between pins 1 and 2 per the little numbers molded into the rear connector and got no meter movement at all. I used my analog meter because the battery in my digital one is suspected to be dead, almost. Am I testing resistance at the right location? Does this indicate a dead CPS?

[shogun]

Page 7100-0-14 under component location chart and component location view
Figure 3 RH front of engine, M20 engine, M30 engine similar
B201 cylinder indentification sensor
B202 engine speed/reference point sensor
http://shark.armchair.mb.ca/~dave/BMW/e34/e34_90.pdf

B201 cylinder id
GE pin 31
SW pin 8

B202 engine speed sensor
GE pin 48
SW pin 47
http://www.bigcoupe.com/phpBB2/viewtopic.php?p=69149&sid=f00b0bc6d8b011463f1354365c46e2b2

Have searched a lot but cannot find a better picture

The other one should be the donut http://bmwe32.masscom.net/sean750/Replacing_sparkplugWiringV12/NewAssembledLead.jpg

EDIT: found the perfect pic http://paulaxford.com/html/bmw730i/checking_sensors.htm

[ahlem]

I was checking connections x1521 and x1522. x1522 appears to be the connection for the CPS as shown on the shark link above on page 7100-0-14 figure 2.
That is where I didn't get and reading when I probed with my ohmmeter. Does that mean my CPS or the wires attached to it are toast?
I will try to start the car again this evening after I check the pins again when they are cold. Is there a possibility that my oil leak at the front of the engine has caused my CPS to fail? It's pretty well covered with crud.
Thanks for the insights by the way.

[632 Regal]

Is there a possibility that my oil leak at the front of the engine has caused my CPS to fail? It's pretty well covered with crud.
Thanks for the insights by the way.

Absolutely disconnect it and spray it out with brake cleaner. I have trans problems and it seems to be a common thing with connectors not communicating. I'll be into mine tomorrow.

[ahlem]

The oil is covering the "hall effect" pickup end of the CPS. The wire connector at the black plastic cover next to the valve cover appears to be real clean. Is it possible to gum up the pickup end?

[ahlem]

Today I changed the CPS and the car has been running pretty well. The old one failed the ohms test. I tested the new one before I put it on. Fingers crossed.

[632 Regal]

The oil is covering the "hall effect" pickup end of the CPS. The wire connector at the black plastic cover next to the valve cover appears to be real clean. Is it possible to gum up the pickup end?

I doubt it unless the crud contains metal remnants from another issue. Blow all connections with brake cleaner and reconnect unless they are green. My car has a metallic sheen on things behind the AC pump which might be the issue with mine.