question about cam pulley, cam sensor

jsteele22 · #1 10-04-2006, 02:39 PM

I'm trying to decipher the cam/crank timing signals that the ECU uses, with the goal of running the engine with MegaSquirt. The two toothed wheels on the crank are clearly visible with the black plastic cover removed, but I'm having a harder time with the cam senor. It looks like there is only one "tooth" on the back of the (driver side) cam pulley, so there would be one pulse per 720 degrees of crank rotation. But it's hard to be sure without removing the pulley. Can somebody tell me for sure ? (I know that an EJ25 has two teeth back there.)

Earthworm · #2 10-04-2006, 02:45 PM

There are 3 sensors in total. Just making sure you haven't missed that last one.

jsteele22 · #3 10-04-2006, 03:24 PM

Quote:

Originally Posted by Earthworm

There are 3 sensors in total. Just making sure you haven't missed that last one.

Yeah, the two sensors for the crankshaft each have a toothed wheel behind the crank pulley. Those teeth patterns are easy to see, at least when you've got the timing cover off. The third sensor, which reads raised bumps off of the back of the cam pulley is harder - I don't have the cam pulley removed, so I'm just sort of peeking through the sprockets.

oab_au · #4 10-04-2006, 05:45 PM

Quote:

Originally Posted by jsteele22

Yeah, the two sensors for the crankshaft each have a toothed wheel behind the crank pulley. Those teeth patterns are easy to see, at least when you've got the timing cover off. The third sensor, which reads raised bumps off of the back of the cam pulley is harder - I don't have the cam pulley removed, so I'm just sort of peeking through the sprockets.

Yes there is only one bump on the back lf the cam gear.

The way the three sensors work together is:

Looking from the front of the engine, the one on the left hand side, at an angle, is the No. 1 crank sensor. It is the 'clock' signal, putting out a pulse every 30* crankshaft degrees. It is used for timing Injection start time, Ignition timing, engine rpms.

The No.2 sensor is the one vertically above the crank, It sends a set of pulses, which tells which bank of pistons are at TDC, 1/2, 3/4, or 5/6.

The Cam Sensor tells which of the pistons in the bank, 1 or 2, 3 or 4, 5 or 6 is on compression, so that Ignition is sent to the right cylinder.

The four cylinder engines have a wasted spark, so they have two protrusions on the cam gear.

Harvey.

jsteele22 · #5 10-05-2006, 10:41 AM

Quote:

Originally Posted by oab_au

Yes there is only one bump on the back lf the cam gear.

The way the three sensors work together is:

Looking from the front of the engine, the one on the left hand side, at an angle, is the No. 1 crank sensor. It is the 'clock' signal, putting out a pulse every 30* crankshaft degrees. It is used for timing Injection start time, Ignition timing, engine rpms.

The No.2 sensor is the one vertically above the crank, It sends a set of pulses, which tells which bank of pistons are at TDC, 1/2, 3/4, or 5/6.

The Cam Sensor tells which of the pistons in the bank, 1 or 2, 3 or 4, 5 or 6 is on compression, so that Ignition is sent to the right cylinder.

The four cylinder engines have a wasted spark, so they have two protrusions on the cam gear.

Harvey.

Awesome, thanks Harvey.