Technical help Q & A Got A technical problem with you car? Keep it in here where the techies hang out and we will try to solve it for you!!

Cosworth crank sensor voltage

Old 02-07-2019, 09:00 PM
  #1  
Topjoe9
Wahay!! I've lost my Virginity!!
Thread Starter
 
Topjoe9's Avatar
 
Join Date: Jul 2015
Location: Caithness
Posts: 65
Received 2 Likes on 2 Posts
Default Cosworth crank sensor voltage

I've been carrying out tests on my crank sensor. I've been told I should have at least 2volts at ecu pins 3 and 4 whilst cranking the engine with ecu disconnected.
im getting nothing so presume sensor failure or break in the loom.
Is the test procedure correct or am I doing something wrong?
Thanks for your help.
Old 04-07-2019, 12:46 PM
  #2  
martysmartie
PassionFord Post Whore!!
iTrader: (1)
 
martysmartie's Avatar
 
Join Date: Dec 2007
Posts: 8,460
Received 102 Likes on 100 Posts
Default

Are you measuring AC voltage?

If so, yes it's faulty.

Martin
Old 06-07-2019, 01:44 PM
  #3  
stevieturbo
C**t
 
stevieturbo's Avatar
 
Join Date: Oct 2003
Location: Norn Iron
Posts: 7,912
Received 258 Likes on 237 Posts
Default

scope it, a multimeter is almost useless.

Voltage will vary with rpm, and could be as low as say 0.5 volts to a few hundred at higher rpm's and will be a waveform. NOT a steady voltage.
Old 07-07-2019, 12:09 PM
  #4  
Topjoe9
Wahay!! I've lost my Virginity!!
Thread Starter
 
Topjoe9's Avatar
 
Join Date: Jul 2015
Location: Caithness
Posts: 65
Received 2 Likes on 2 Posts
Default

Thanks for the replies, My problem is my car is running a p8 ecu which is in limp mode. I've now replaced crank,phase, air and water temp sensors, tried another map sensor, set tps and base idle and still have the fault.
Om going to try to reset the ecu again as this may be the problem. When I try to do the reset procedure I don't get the very quick clicks as I'd expect even when being done on a standard chip.
Any ideas on anything else it could be ?
cheers.
Old 07-07-2019, 12:15 PM
  #5  
stevieturbo
C**t
 
stevieturbo's Avatar
 
Join Date: Oct 2003
Location: Norn Iron
Posts: 7,912
Received 258 Likes on 237 Posts
Default

Rather than doing random shit and throwing needless parts at it....some proper diagnostic procedure might help.

And what is this actual problem...and how are you determining what limp mode might be ?

http://bigturbo.co.uk/
Old 07-07-2019, 07:35 PM
  #6  
Topjoe9
Wahay!! I've lost my Virginity!!
Thread Starter
 
Topjoe9's Avatar
 
Join Date: Jul 2015
Location: Caithness
Posts: 65
Received 2 Likes on 2 Posts
Default

I'm determining limp mode as it runs perfectly until exactly 4000 rpm then will not rev past it. I've been diagnosing the wiring and sensors using manuals and guides found on other threads.
the sensors I've replaced along the way have been spares I have which are known to be working.
Old 07-07-2019, 09:29 PM
  #7  
stevieturbo
C**t
 
stevieturbo's Avatar
 
Join Date: Oct 2003
Location: Norn Iron
Posts: 7,912
Received 258 Likes on 237 Posts
Default

So you've made up a limp mode ?

Check for fault codes, it will be a sensible first step, rather than throwing parts at it. It may be a basic system, but in the absence of anything else, it will be a starting point
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Roosie
General Car Related Discussion.
2
08-04-2012 06:26 PM
Roosie
General Car Related Discussion.
4
10-06-2008 04:36 PM
gibbo frst
General Car Related Discussion.
1
08-03-2007 02:15 PM
SteveB
Technical help Q & A
3
09-07-2006 03:34 PM
Matt
General Car Related Discussion.
6
27-07-2005 07:41 AM


Thread Tools
Search this Thread
Quick Reply: Cosworth crank sensor voltage



All times are GMT. The time now is 07:35 AM.