M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine management => Topic started by: KenC on October 11, 2007, 09:27:17 AM
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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?
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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?
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check the fuseable link
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check the fuseable link
would the entire electronic system work including the fuel injection if the fusible link was broken?
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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?
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not sure, but the car wont run if they arn't working. Yes you can ground to the VC.
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Update:
Plugs ARE sparking. Fuel IS reaching cylinders.
Timing?
Mixture?
I'm at a total loss.
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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.
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did you check cam and crank sensors hot and cold? sounds a lot like a crank sensor...
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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.
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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.
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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... ;)
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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.
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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.
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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!
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coils connected to the right cylinders...?
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coils connected to the right cylinders...?
I should edit the title of the thread.
After further investigation, I AM getting spark. Just won't start.
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yeah, you will get spark if they're connected wrong, you will just get spark at the wrong time which will make it not start.
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Are you sure your fuel pump is working ? Can you hear it when you turn the Key to the on position ? There is supposed to be around 42 pounds of pressure in the fuel system .
Sounds to me like the fuel pump went or is going and not making enough pressure. Connect a fuel pressure guage at the tank under the seat to make sure you are getting fuel pressure .
good luck
also check your fuel pump relay
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The fuel pump is fairly new (from the dealer) and it is working. Fuel is reaching the cylinders.
Wires are connected to the right cylinders.
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UPDATE:
Tried the WOT start - Nothing
Pulled the valve cover off. Rotated the crank to TDC. Cams looked to be pretty perfect. Hasn't jumped a tooth.
We're still baffled at this point.
We decide to compression test it just for shits. I had done this about a month ago and got 190-210 on all four so I wasn't expecting anything too drastically different. Boy was I wrong.
ALL cylinders are reading 80-100psi for compression.
We put the valve cover back on and did a leak down on three of the cylinders - 90% leakage on all of them. We can't find where it's leaking from, but it sounds like the air is coming right back up from the sparkplug holes.
We then do another compression test. ZERO compression now. I'm not sure how in the course of 15-20 minutes I could go from 80-100psi (which is WAY low for the M42) down to absolutely nothing.
We even had a running M42 to compare with so we could rule out the gauges being faulty.
We're pulling the head tomorrow.
WTF could cause that? All of the cylinders have essentially no compression now.
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dip your compression tester screw in oil, or rub it around it and redo it and make sure it has the 0ring on it
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dip your compression tester screw in oil, or rub it around it and redo it and make sure it has the 0ring on it
We did. And we tested it on another M42 to make sure it wasn't fouled.
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We took the head off of the car last night and everything looked fine. It's going to be pressure tested today or tomorrow. If everything turns out well we're going to get another gasket and slap it back on.
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talk about strange, I've been thinking of ideas for you but am coming up empty, let me know what happens when its all back together, that compression issue is strange...
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Hey, have you figured out what the problem was?
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Hey there, this is my first post, so not to sound like an idiot, but I have seen several scenerios like the one you described...
First, the fuel pressure regulator goes iffy, allowing too much pressure, flooding the engine.
Each cylinder is soaked in gas, which washes the cylinder down and gives the impression of having no compression. One remedy is squirting a little bit of motor oil in each cylinder AFTER a good suirt of STARTER FLUID. Usually will crank right up.
I know it sounds bizarre, but I've seen it happen. One minute all is fine, then the next, it isnt running and after a compression test, it's bad news. All this because the cyclinders got totally soaked with fuel.
Just my .02, hope it helped allthough, the thread started two months ago....
Cheer and beers
Hodge
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Sounds plausible. I'm going to give it a try tonight.
Was working after reassembly, but is dead again.
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Success.
I just dumped like a cap and a half of oil into each cylinder and it fired up. I'm going to order a new FPR tomorrow.
I don't think it's the rings because it's not a constant problem. That and I compression checked the engine luke-warm a few months ago and it was 190-200 on all of them.
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where abouts is the fuel pump relay cause this sounds like the same problem i have
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its under the plastic wire cover across engine bay near the wiper linkage
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glad to have helped...
keep us in the loop guys.
cheers and beers
Hodge