M42 Won't Start

[KenC]

I drove the car to work, and it ran fine.  When I went out to start it up after work it just cranked and cranked.

swapped ECU - no change

fuel IS getting to the cylinders

both cam and crank position sensors are WELL within normal ohm range

NO faults with pedal codes

main white relay is working


Any ideas???
Is it possible that all of my plugs fouled at the same time?

[kowalski]

are all the cylinders not getting any spark? get a good plug and try the arc test. pull 1 plug off at a time and turn the car over with the plug attatched tot he wire and grounded to something. i would advise wearing a rubber clove or something to insulate yourself. see which cylinders have spark and which don't. are the other 2 relays beside it working?

[nickmpower]

check the fuseable link

[KenC]

check the fuseable link

would the entire electronic system work including the fuel injection if the fusible link was broken?

[KenC]

are all the cylinders not getting any spark? get a good plug and try the arc test. pull 1 plug off at a time and turn the car over with the plug attatched tot he wire and grounded to something. i would advise wearing a rubber clove or something to insulate yourself. see which cylinders have spark and which don't. are the other 2 relays beside it working?

Can I ground the plugs to the valve cover and/or intake manifold?

I'm 99% sure the two orange relays are working.  What do they control?

[kowalski]

not sure, but the car wont run if they arn't working. Yes you can ground to the VC.

[KenC]

Update:

Plugs ARE sparking.  Fuel IS reaching cylinders.

Timing?
Mixture?

I'm at a total loss.

[D. Clay]

With unburned fuel going through the motor, spark at the wrong time usually produces a misfire or backfire. A broken timing chain/gears usually gives you a peculiar sound when cranking. No compression variation because valves are open like cranking with no plugs. If that's the case, I'd pull the valve cover and either thank the Virgin or remark upon her questionable ancestry. This is a puzzler because of the no error code scenario and the way it quit running while sitting still. I thought only older English cars did that.

[kowalski]

did you check cam and crank sensors hot and cold? sounds a lot like a crank sensor...

[KenC]

did you check cam and crank sensors hot and cold? sounds a lot like a crank sensor...

Replaced both of them with ones from a known running M42.  That and both of them tested well within range with a multimeter.

Still nothing.

[KenC]

With unburned fuel going through the motor, spark at the wrong time usually produces a misfire or backfire. A broken timing chain/gears usually gives you a peculiar sound when cranking. No compression variation because valves are open like cranking with no plugs. If that's the case, I'd pull the valve cover and either thank the Virgin or remark upon her questionable ancestry. This is a puzzler because of the no error code scenario and the way it quit running while sitting still. I thought only older English cars did that.

There is no backfire or misfiring occuring.

It is just cranking and cranking.  Nothing sounds out of the ordinary.

Should I pull the valve cover and crank it?  That would show whether or not the cams are turning properly.  I'm assuming I should cut the fuel pump prior to this.

[318idol]

How are you cranking the car over for the plug/fuel tests?  With a remote starter, or someone inside using the ignition key?  I ask, because it's possible for the ignition key/switch, when trying to start the car will spin the starter but lose power to the coil and/or fuel pump.  However, if you turn the key to activate the car's electrical system and fuel pump -- and use a remote starter to spin the engine, everything will work fine.  But when you turn the key all the way to engage the starter, it basically makes the starter spin, but cuts out power to everything else.  I had this happen on a fuel-injection Chevy I rewired and picked up the wrong hot from the fuse panel.  

A long shot, but it would explain why you'd get spark and fuel while using a remote starter -- but nothing when using the ignition key.  One way to test would be to try and push-start the car.  Or check fuel pump and coil power when the key is activating the starter.  If that is the case, you'd need a new ignition switch.  Make sense?  I didn't think so...  

[KenC]

A long shot, but it would explain why you'd get spark and fuel while using a remote starter -- but nothing when using the ignition key.  One way to test would be to try and push-start the car.  Or check fuel pump and coil power when the key is activating the starter.  If that is the case, you'd need a new ignition switch.  Make sense?  I didn't think so...  

I'm getting fuel AND spark while using the key.

I pulled a plug and grounded it on the intake valve cover while turning the key.  It sparked like it should.  Then when I removed the other plugs they were all damp from the fuel.

[silverblades181]

Try cranking the engine with the throttle at WOT. I don't know if the M42 is like that but most engine will enter in a "unflooding" mode.

[318idol]

Bizarre... Guess it could have just been flooded.  Do you get spark with all the plug?  Did you remove all plugs and let the ending dry out?  Swap in new plugs?

What happened with my Chevy I had rewired, is that since cars rely on so much juice while running the starter, they cut power to certain systems when the starter is engaged.  I had the fuel pump hooked to the light circuit, which was cut off during the starting process.  I'd have juice to the injectors with key simply turned on, but when you engaged the starter, the injectors fell dead: No start.  Very odd.

Good luck!