Author Topic: car wont idle?  (Read 4206 times)

Rally Culture

  • Newbie
  • *
  • Thank You
  • -Receive: 0
  • Posts: 38
  • Freshly Registered!
    • View Profile
car wont idle?
« on: July 09, 2014, 02:10:09 AM »
i have a 91 318is m42 motor. i have to constantly give the car throttle to keep it from staling and it sometimes wont rev past 4k or it just wont go any where with my foot on the floor in any gear it also starts to sputter. it acts like its in limp mode i checked the check engine light 1st go it was camshaft/ cylinder id sensor. so i changed the cam sensor and it helped let the car rev a bit more freely but still goes on and off with limp mode. im thinking i need to change the crank sensor too? after i cleared the code and drove the car now its switching from emission (lambda) control to vehicle speed signal not present? the car runs better after swapping out the cam sensor but still falls on its face at wot and wont idle. what do you guys think? crank sensor? or something else?
« Last Edit: July 09, 2014, 02:16:41 AM by Rally Culture »

Darky

  • Hero Member
  • *****
  • Thank You
  • -Receive: 23
  • Posts: 630
    • View Profile
Re: car wont idle?
« Reply #1 on: July 09, 2014, 03:18:53 AM »
Have you checked for air leaks? After afm
Icv is another possibility
Cheerrs

deansweet

  • Hero Member
  • *****
  • Thank You
  • -Receive: 12
  • Posts: 530
    • View Profile
Re: car wont idle?
« Reply #2 on: July 09, 2014, 07:10:23 AM »
test crank sensor?
when I was looking in to my stalling issue I was told the cam sensor would not cause the car to die but the crank sensor would.
It's supposed to be in the 500-600ohm range but mine was 900+. Swapped it out and haven't seen the issue since.

Dean

Nick_318is

  • Sr. Member
  • ****
  • Thank You
  • -Receive: 11
  • Posts: 378
    • View Profile
Re: car wont idle?
« Reply #3 on: July 09, 2014, 07:44:00 AM »
Sounds like a vacuum leak or something wrong with the ICV.  When I did the mess under the intake I know I installed mine the wrong way and the car ran like shit until I turned it around, then everything was great.

Rally Culture

  • Newbie
  • *
  • Thank You
  • -Receive: 0
  • Posts: 38
  • Freshly Registered!
    • View Profile
Re: car wont idle?
« Reply #4 on: July 09, 2014, 02:25:41 PM »
i sprayed all hoses and seals to check for leaks and nothing. i went to clear the code today and drove it to see if its consistent and the c9 emission control came back on. when light is on car wont rev above 2k and sputters. what all is apart of the emission control? im thinking it might be the crank sensor when i was looking at it there were some exposed wires that are prob causing it to short. i got a friend who has an e36 crank sensor would that work for my e30?

DesktopDave

  • Administrator
  • Legendary
  • *****
  • Thank You
  • -Receive: 60
  • Posts: 5076
  • Lives in the 80s
    • View Profile
    • The Iconic BMW
Re: car wont idle?
« Reply #5 on: July 09, 2014, 03:12:09 PM »
Any exposed wires are bad on a position sensor. The outer jacket is a shield for the signal wires. If you have a multimeter, test pins 1 & 2 on the sensor. Should be about 1280 for the cam sensor and about 680 for the crank. Test the other two pairs as well (2 & 3, 1 & 3) - those should be very high, like 100K ohms.

I don't think the sensor heads are the same length on the M44 crank sensor, but all the M42 parts are the same regardless of model. Your buddy's sensor should work for you.
'08 Karmesinrot 128i 6MT
'86 Zinnoberrot 635CSi (M30B32/G265/3.46 torsen LSD)

Sold: '97 Montrealblau 318iS, '91 Brilliantrot 318i, '91 Brilliantrot 318iS

Rally Culture

  • Newbie
  • *
  • Thank You
  • -Receive: 0
  • Posts: 38
  • Freshly Registered!
    • View Profile
Re: car wont idle?
« Reply #6 on: July 12, 2014, 06:24:53 PM »
so my friend had one for an e36 but wasnt for the m42  :( and i found one on ebay for cheap but its listed for an e36 with the m42 motor and i just want someone that has had experience with this to confirm it before i buy something that wont work.

DesktopDave

  • Administrator
  • Legendary
  • *****
  • Thank You
  • -Receive: 60
  • Posts: 5076
  • Lives in the 80s
    • View Profile
    • The Iconic BMW
Re: car wont idle?
« Reply #7 on: July 13, 2014, 04:22:18 PM »
The E36 after '96 has the M44 motor - that crank sensor is not compatible with the earlier M42. The M44 unit mounts on the side of the block, not on the lower cam case like all the M42 cars.

All M42 sensors are the same from what I've heard. You can cross-check any BMW part number here at RealOEM, among other places. My E30 comes up with Pulse Generator (updated PN) 12141721504. RealOEM tells me I'm wrong, that the E30 sensor is unique. At times, BMW will issue different part numbers based on cable lenghts or some other unimportant detail. I'd stick with the correct PN in this case as the cable length is pretty important in our cars.

I found two compatible parts at RockAuto for about $70 (+shipping):
http://www.rockauto.com/catalog/moreinfo.php?pk=936449&cc=1011249
http://www.rockauto.com/catalog/moreinfo.php?pk=443168&cc=1011249
Bosch OEM is $94 there.

'08 Karmesinrot 128i 6MT
'86 Zinnoberrot 635CSi (M30B32/G265/3.46 torsen LSD)

Sold: '97 Montrealblau 318iS, '91 Brilliantrot 318i, '91 Brilliantrot 318iS