Crankshaft Positioning Sensor Impulse Wheel...

[e36Vertrag]

Hey guys...I am new here, and new to e36's all together.

I have Chris Pettit's old '97 318ti, and after much diagnosis, I think I have finally figured out the problem. Here's what's going on:

• Car cranks strong, but won't start
• Has and holds good compression on all 4 (175–185)
• ALL of the electrical has been thoroughly inspected, and everything chacks fine.

Here's what I saw:
• When I remove the crankshaft pos. sensor (CPS), I see about 6 or 7 teeth chewed up on the impulse sending wheel (ISW). So... the only way to alleviate this issue is the remove the crank, and replace that wheel. In theory...the car should start and run.

My question... Has anyone EVER had this happen? It seems like a small likelihood.

My next question... Can I access this by pulling the oil pan, and then dropping the crankshaft?

Here's a pic for reference:



TIA!

[xxxJohnBoyxxx]

Originally Posted by e36Vertrag

Hey guys...I am new here, and new to e36's all together.

I have Chris Pettit's old '97 318ti, and after much diagnosis, I think I have finally figured out the problem. Here's what's going on:

• Car cranks strong, but won't start
• Has and holds good compression on all 4 (175–185)
• ALL of the electrical has been thoroughly inspected, and everything chacks fine.

Here's what I saw:
• When I remove the crankshaft pos. sensor (CPS), I see about 6 or 7 teeth chewed up on the impulse sending wheel (ISW). So... the only way to alleviate this issue is the remove the crank, and replace that wheel. In theory...the car should start and run.

My question... Has anyone EVER had this happen? It seems like a small likelihood.

My next question... Can I access this by pulling the oil pan, and then dropping the crankshaft?

Here's a pic for reference:

http://img.photobucket.com/albums/v3...LOEMCrank1.jpg

TIA!

How did the teeth get chewed up? Are there chunks missing? Is the sensor damaged? Is it throwing a code for bad crank sensor?

Does the car fire at all?

Before pulling the crank check for spark with all plugs out and spark plugs on the wires do this at night. Also see if your getting fuel pressure? A few missing teeth should still give you spark it will just be eratic and the car should misfire or almost start then stall. No codes, spark or fuel pressure and I bet it's a EWS issue which I can help with too.

If it is the crank teeth and the motor is in good condition I would take the easy route and install a 1995 front mount crank position sensor that reads off the balancer (lower pulley). I have a 1997 318is OBDII with a stroker crank so it didn't have the teeth on the crank so it was a easy conversion to use the front mount sensor. If your balancer has teeth on it (mine did) you can use that balancer and replace the front cover for the one that has the sensor mount on it or weld a mount on there to hold the sensor or even JB weld it there...Way easier then pulling the crank. I would never try to install a crank in a motor with the engine in the car. With the motor out you need 3 people just to install the crank with the pistons in their holes and rods hanging out the bottom....One to install the crank and 2 to hold rods so they don't ding the journels.

Let me know the answers to my questions and I will try to help you

[e36Vertrag]

Originally Posted by xxxJohnBoyxxx

How did the teeth get chewed up? Are there chunks missing? Is the sensor damaged? Is it throwing a code for bad crank sensor?

Does the car fire at all?

Before pulling the crank check for spark with all plugs out and spark plugs on the wires do this at night. Also see if your getting fuel pressure? A few missing teeth should still give you spark it will just be eratic and the car should misfire or almost start then stall. No codes, spark or fuel pressure and I bet it's a EWS issue which I can help with too.

If it is the crank teeth and the motor is in good condition I would take the easy route and install a 1995 front mount crank position sensor that reads off the balancer (lower pulley). I have a 1997 318is OBDII with a stroker crank so it didn't have the teeth on the crank so it was a easy conversion to use the front mount sensor. If your balancer has teeth on it (mine did) you can use that balancer and replace the front cover for the one that has the sensor mount on it or weld a mount on there to hold the sensor or even JB weld it there...Way easier then pulling the crank. I would never try to install a crank in a motor with the engine in the car. With the motor out you need 3 people just to install the crank with the pistons in their holes and rods hanging out the bottom....One to install the crank and 2 to hold rods so they don't ding the journels.

Let me know the answers to my questions and I will try to help you

First off...thanks for the reply! Here goes...

• I am getting spark on all 4, and fuel pressure is good. The fuel was diluted, so I drained the tang and put 5 gallons of 91 in.

• No codes, and the GT1 is communicating with the DME. The car cranks and cranks, and even acts like it is about to start, but then doesn't.

• Motor has and holds good compression.

• I like the idea of installing a front mount CPS. Are you referring to mving the CPS to the front vibration damper? If so...this would be an excellent approach! Please just let me know what parts I need to pull from an OBDI car.... I would much rather do this than pull the motor, or try to remove the crankshaft through the oil pan.

Thanks!

[xxxJohnBoyxxx]

Originally Posted by e36Vertrag

First off...thanks for the reply! Here goes...

• I am getting spark on all 4, and fuel pressure is good. The fuel was diluted, so I drained the tang and put 5 gallons of 91 in.

• No codes, and the GT1 is communicating with the DME. The car cranks and cranks, and even acts like it is about to start, but then doesn't.

• Motor has and holds good compression.

• I like the idea of installing a front mount CPS. Are you referring to mving the CPS to the front vibration damper? If so...this would be an excellent approach! Please just let me know what parts I need to pull from an OBDI car.... I would much rather do this than pull the motor, or try to remove the crankshaft through the oil pan.

Thanks!

Left you a voice mail and replied to your email. The front crankshaft position sensor is super easy to install and is 100% OBDII compliant. It was used when they were just switching from OBDI to OBDII

[e36Vertrag]

Originally Posted by xxxJohnBoyxxx

Left you a voice mail and replied to your email. The front crankshaft position sensor is super easy to install and is 100% OBDII compliant. It was used when they were just switching from OBDI to OBDII

Thanks! Got it...

This could be end up working out really well, but I'm still not holding my breath. Seems like I've had such schi†† luck with this car so far. If this works... it basically means not pulling the motor!

[J!m]

Originally Posted by xxxJohnBoyxxx

I would never try to install a crank in a motor with the engine in the car. With the motor out you need 3 people just to install the crank with the pistons in their holes and rods hanging out the bottom....One to install the crank and 2 to hold rods so they don't ding the journels.

I have built up a lot of engines over the years and never dinged a crank journal.

Slide some rubber hose over the rod cap bolts like everyone else does!

I agree fully that doing crank work in-car sucks. I'd never do that either unless I had to for some reason... In the ti, I doubt you could even get the pan off without dropping the sub-frame. If you do that much work, you might as well pull the motor all together.