M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Electrical => Topic started by: longms on January 12, 2010, 09:56:02 AM
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My car abruptly died when I stopped at a light yesterday and have been searching high and low about this problem and everything is pointing me towards these sensors. I am getting 1-2-2-2 from the "stomp test." Which this code really doesn't tell you anything.
I am not really familiar with using a multimeter and checking electronics. When I pull these sensors I have gathered that the cam should read about 1200 ohms and the crank should read about 650 ohms. Where on the sensors should I be touching the leads??? Should the car be on the "on" position, should it be cranking or should the car be off? I am not sure what I am doing and am looking for some direction.
I am also checking the DME relay and am not sure what readings I should be getting and between what plugs they should be reading from. My last fear is that I have a faulty computer in my car.
I am trying to get parts ordered today and get them shipped overnight so I can possibly have a car by the end of the week. Thanks fellas.
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I don't totally agree with your diagnosis. The 1222 code is an O2 sensor problem, likely from a big vac leak, faulty AFM or old O2 sensor. Here's a good list of codes (http://e30world.com/fuel/BMW-E30-DME-Motronic-fault-codes) & a little good advice. Likely as not you might have more than one problem.
I'd start with the fundamentals. Is the car getting a spark? Is it getting fuel? Is there any cracks in the intake boot or ICV pipes? Replace them or tape them up if so. They'll stop the engine if they're too big.
Your DME is likely OK, since it sends codes. It wouldn't light the CEL if it was dead. Sure it's possible, but not likely.
I don't think the cam sensor can set a code if it's bad, but it's only for fine-tuning the timing...it'll make the car run rough but it should still run.
The crank sensor will stop the car but not set a code at all (you'll get a 1444 normally, the all clear code). The fuel pump will not run but the engine will turn over. If the crank sensor doesn't have enough resistance it can't send a clear signal to the DME/ECU and the DME locks out the fuel pump for safety reasons (it assumes the car isn't running & prevents fuel from flowing intentionally).
You can test these sensors at their connectors on the engine conduit...it's a long black metal channel that runs between the upper & lower intake manifold. Car should be off. You'll see the two connectors near the front of the engine (by the oil filter housing) on the driver's side. Pull those plugs & probe them with the multimeter. Top is the cam, bottom is the crank. Here's a pic of the engine, look at the very top center for the two black plugs I'm talking about:
(http://i729.photobucket.com/albums/ww299/desktopdave/th_IMG_1464.jpg) (http://s729.photobucket.com/albums/ww299/desktopdave/?action=view¤t=IMG_1464.jpg) You can see the black conduit too, bolted to the intake manifold support bracket.
I don't want to sound like a jerk, so if you know what I'm talking about just ignore all this:
To use the multimeter (or DMM) you'll have to set it on ohms or Kohms (1000+ ohms) to test for resistance to electricity. Make sure you have the DMM plugs in the right sockets too. Mine has a single ground for the black probe, but two for the red probe. You have to move the red probe from one plug to another depending on the test you want to run. On mine, like most, the high-current amperage tests are dedicated to one socket, all the others run off the other one. You might have to learn the symbols for the tests to be sure which is correct...resistance is measured in 'ohms' and the symbol is a Greek omega. Sort of looks like an 'O' with feet.
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Thanks for all of this information.
Symptoms so far:
No Spark
No fuel that I smell (when I pulled the plugs)
All hoses are brand new but will give them a once over tonight.
Would a bad O2 sensor cause the car not to start at all? If the crank sensor were bad and not sending a signal would that car be able to run? My understanding is that it would not be able to run at all.
I will probe the plugs on the sensors when I get home from work. Do those numbers sounds about right when checking the sensors?
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You need to get the bentley manuals to work on these cars............
(http://i141.photobucket.com/albums/r73/bogeyman700/silvere36.jpg)
(http://i141.photobucket.com/albums/r73/bogeyman700/rede30.jpg)
Below is a link to no start issues and testing of the cps.
good luck
http://m42club.com/forums/showthread.php?t=5462&highlight=cps+testing
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Thanks for all of this information.
Symptoms so far:
No Spark
No fuel that I smell (when I pulled the plugs)
All hoses are brand new but will give them a once over tonight.
Would a bad O2 sensor cause the car not to start at all? If the crank sensor were bad and not sending a signal would that car be able to run? My understanding is that it would not be able to run at all.
I will probe the plugs on the sensors when I get home from work. Do those numbers sounds about right when checking the sensors?
Yeah, sounds like a bad CPS. Test & report on the resistance. Your numbers are correct, roughly 600 ohms on the crank & 1200 ohms on the cam sensor IIRC.
You can also isolate the problem by pulling the fuel pump relay & short socket pins 30 & 87 with a bit of 14-16 gauge wire. Then turn the key on, to position II. If the fuel pump now runs (it won't turn off BTW) you know it's likely the CPS is bad.
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RED IS 91- I know, I know...I do need to get those manuals. They would probably answer a lot of questions that I seem to have.
Thanks for the responses. I will try the short socket method for fuel pump relay and check the resistance on the sensors.
If it turns out to be the cps should I replace bith crank and cam sensors? And, where can one order the crank position sensor? Are the crank and cam sensor basically the same thing? I can't seem to find it on Pelicanparts.com.
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I didn't find it there either. Likely you could call. I did find one here:
http://www.partsgeek.com/catalog/1991/bmw/318is/engine_mechanical/crank_position_sensor.html
I'd replace only what was dead...crank & cam sensor are basically the same style of sensor, with different mounts & likely different sensitivities.
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Yeah, sounds like a bad CPS. Test & report on the resistance. Your numbers are correct, roughly 600 ohms on the crank & 1200 ohms on the cam sensor IIRC.
You can also isolate the problem by pulling the fuel pump relay & short socket pins 30 & 87 with a bit of 14-16 gauge wire. Then turn the key on, to position II. If the fuel pump now runs (it won't turn off BTW) you know it's likely the CPS is bad.
Sorry for the Hijack:
but Dave, If my car's fuel pump is turning off causing my car to bog due to crank position sensor, or soem other sensor, could I jumper this, and drive it around the block to see if it continues to bog? If it doesnt bog that means that it is getting a signal to turn off the fuel pump? If it does, it must be ignition then? or the Injectors are getting a signal to turn off.
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I am not sure if those pictures are representative to what the sensors really look like but those look way different than what the stock ones look like. I can get those or should I get the from Bmrparts.com? $50 gets a used one with a 6 month guarantee on it.
I am getting them overnighted and the bmrparts is charging $35 and the partegeek will charge $25. So they are basically the same price. I am thinking the brand new one is the better call.
Correct me if I am wrong.
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Go to http://www.bavauto.com/
enter your car info and type in the search crankshaft position sensor and it will pop up.
They are a great asset .
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These are on this site ............
this will get you the manual for your engine I believe..........
http://m42club.com/forums/showthread.php?t=2282
This one for your body..............
http://m42club.com/forums/showthread.php?t=964
The books are a lot better but maybe this will get you in right direction.
Good luck
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just tested the sensors and got 1.195 Kohms (which is 1195 ohms iirc) from cam sensor and tried every possible combination between the 3 prongs on the crank sensor and could not get a reading anywhere.
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Sorry for the Hijack:
but Dave, If my car's fuel pump is turning off causing my car to bog due to crank position sensor, or soem other sensor, could I jumper this, and drive it around the block to see if it continues to bog? If it doesnt bog that means that it is getting a signal to turn off the fuel pump? If it does, it must be ignition then? or the Injectors are getting a signal to turn off.
That's a tough call. I'd suspect a flaky relay, connector or pump. Possibly a fuel line leak or FPR too. IIRC you'd replaced most of those though. If you shorted the FP relay the pump would run all the time the key is on. Might be useful for troubleshooting, try it out and let us know how it goes.
I'm an computer geek so I always test, test, test.
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just tested the sensors and got 1.195 Kohms (which is 1195 ohms iirc) from cam sensor and tried every possible combination between the 3 prongs on the crank sensor and could not get a reading anywhere.
Yeah, Cam PS checks out...but Crank at zero resistance = very bad sensor. It must be internally shorted & not sending any signal. Isn't that kind of a dumb system? I prefer the impact/rollover fuel shutoffs myself, hopefully I'll never have to use one.
I'd recheck the reading if it was me (mine was jumping around a bit & tested low the last time I did this), but it wouldn't surprise me. Check the dealer price, they might surprise you & be pretty close... Last time I was there the part (radiator bleed screw) was in stock and reasonable. I was like :eek:... :cool:.
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crank sensor at dealer was like $225:eek:...found one at partsgeek for $60...i believe it is a Delphi brand...is this a good brand?
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Just went through this ordeal, IIRC you have to test between pins 1 & 2 on the plug (could be 1 & 3, but I don't think it is). Changing the crank sensor is a mild PITA.
I got the new sensor at autohausaz.com for $66 shipped, it works perfectly.
http://sd.autohausaz.com/autohausaz/detailw.jsp?sid=vz4jqs55w200zo45ur2fuqyl&partner=autohausaz&product=W0133-1662132
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crank sensor at dealer was like $225:eek:...found one at partsgeek for $60...i believe it is a Delphi brand...is this a good brand?
I just showed you a few post above how to get one at bavauto . Don't go cheap on these cars or you'll regret it.
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Ordered the part from partsgeek and it should be here tomorrow. Cross your fingers and wish me luck...anything else I should address while I have the car up on jacks for this issue?
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sounds like you have it covered for all the things I can think of while car is up, your sig reads like it has all been gone through .
let us know results
good luck
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haha...thanks
Any tips for replacing the crank sensor? Anything that I should know that might save me a headache???
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Pull off the A/C bracket totally, not just the A/C compressor. You might look at it and think it's possible to leave the compressor mount on...but it isn't. Awful design from BMW. That's the only big trouble with installing it. Also, don't bend the wire around too much. It's shielded cable and will fail if the shielding breaks.
Test the brand new sensor too. They'll give you flack about returning an installed sensor. Some have failed right out of the box...you'll be able to get a new one if it hasn't already been installed.
Make sure the little plastic channel bracket is right (it's on the passenger side of the motor), or the fan belts & pulleys might chew your new CPS cable up. Mine was loose, bolt fell out & the bolt/metal standoff was pressed into the front case!
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Thanks for the heads up on the A/C bracket. I will for sure test the sensor. I am assuming just check the resistance?
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^^^Yep, just resistance, unless you have an oscilliscope & bench PS handy.
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That i do not...I managed to see about 875 ohms or so on the new sensor
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Dicey. Seems a bit high to me. I'd wait & see what other members have to say...I haven't had to replace mine yet so I feel uncomfortable giving a 100% answer.
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Hmmmm....I will check again when I get back from work. I checked quickly on my lunch break.
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876 on the dont...she is going in...I talked to a few people and they seem to think it will be fine.
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876 is fine.....My new one (actually second new one as first brand new one tested low--543) tested out at 900....I was a little concerned also but car fired right up and no problems since...
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Car fired right up and idles better and takes less time to start now. If only I would have known about this stupid distributorless ignition system.
Thanks for all the help guys and I am now the happy owner of a running 318is
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Now all you need to do is clean up the mess under the intake, COP kit, bigger injectors, electric fan conversion and.....Never mind....The list is endless....:D
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Glad we could help. I hope it runs great for decades to come.
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UPDATE:
Car has been running great for about a week now so I think the crank sensor was the issue.
I have one more question. To install the crank sensor one should take out the cam sensor to give the wire holder some slack to run the crank sensor where it needs to be. Or atleast this is what I did. I guess i just want to know if I could get an oil leak around the cam sensor? I have since developed a nice little leak and am wondering if it has a gasket that goes on with it. I dont remember there really being one there.
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Yeah, it has an 18x2 o-ring according to RealOEM (http://www.realoem.com/bmw/showparts.do?model=AJ93&mospid=47318&btnr=11_2683&hg=11&fg=10). It's part 7 in that schematic. Pull the cam cover & see if its stuck in there somewhere. I'd replace it with a new one, they harden over time & leak forever after.
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By the amount of oil that it is leaking I am thinking it is more of an oil pan issue but I dont think that the sensor has an o-ring. It couldnt be missing anywhere cause we have only about 2000 miles on the motor after rebuilding it. I just need to get the o-ring and put it on there.
Thanks again DesktopDave
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I'm guessing mine is leaking from the front main seal or dipstick tube o-ring. When I get the 325 sorted I'll take it apart for repairs & report on my findings...
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hmmm...I didnt think about the dipstick o-ring
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Yep. O-rings for everyone...they're all over this motor. I'll bet the gasket and/or o-ring in my oil filter housing leaks too.
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Motor was freshly rebuilt and all the o-rings were replaced. The only kicker was the care came with no dipstick. Had to source a used and not sure if the o-ring on that is new or not. If this o-ring were dried up could this make a decent amount of leakage? Also, can this o-ring be replaced without draining the oil. I am thinking yes but am not sure.
Thanks.
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I'm honestly not sure. I think you can pull it without draining the oil...it's pretty high on the oil pan.
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mine is at 520 Ohms right now, but hte car starts... do you think this could cause occasionnal misfiring at mid rpms