home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > maintenance & nonperformance

Reply
 
Thread Tools Display Modes
Old 11-28-2016, 11:02 AM   #1
greasegram
Member Board
 
greasegram's Avatar
 
Join Date: Dec 2015
Location: kelowna, bc
Default Failed Crank Position Sensor

About a month ago, i replaced the crank position sensor in my 93 240. Yesterday, my car was having the same symptoms- dies randomly, won't always restart. I pulled the sensor out and visually it looks okay. What could be causing the sensor to fail? Or, is there something else that fails that causes the same symptoms? I've inspected most of the electrical system, and i can't find anything wrong.
__________________
8v death squad
greasegram is offline   Reply With Quote
Old 11-28-2016, 11:34 AM   #2
ZVOLV
<Master Tech>
 
ZVOLV's Avatar
 
Join Date: Nov 2002
Location: California
Default

Lab scope is best way to test one. You can also measure AC voltage.

Or pop open efi relay and observe like linked in me no start thread in sig.
__________________
No Start Thread
ZVOLV is offline   Reply With Quote
Old 11-28-2016, 11:52 AM   #3
greasegram
Member Board
 
greasegram's Avatar
 
Join Date: Dec 2015
Location: kelowna, bc
Default

Snap-On guy said i can demo scope if I need one, i'll give it a try. I'll check the relay too, thanks.
greasegram is offline   Reply With Quote
Old 11-28-2016, 01:06 PM   #4
turbochimp
Board Member
 
Join Date: Nov 2011
Default

I experienced a similiar issue on a 93 240. It was actually the tach wire on the coil grounding out. It was highly intermittent which made it difficult to diagnose. If you have a tach wire connected (red/white maybe?) to the coil, it might be work pulling it and seeing if the problem persists.
turbochimp is offline   Reply With Quote
Old 11-28-2016, 01:10 PM   #5
ZVOLV
<Master Tech>
 
ZVOLV's Avatar
 
Join Date: Nov 2002
Location: California
Default

http://www.forums.turbobricks.com/sh...d.php?t=322395


here is a DEFINITIVE way of testing your ignition components with zero guesswork


Above is my ezk diag thread.
ZVOLV is offline   Reply With Quote
Old 11-29-2016, 01:05 PM   #6
ZVOLV
<Master Tech>
 
ZVOLV's Avatar
 
Join Date: Nov 2002
Location: California
Default

Powerstage is also a common issue. It just happened to me in my 1990 240.

When it dies, you verify if you have spark or not. Simply ground the king lead to the strut tower and crank. Or watch for tach movement, if you have one. Certain models WILL cut power to tach on cranking so be careful on that one. Just pay attention how YOURS works.


A incandescent test light should also blink when put to coil negative on cranking. LED test light should blink when put to the 5v square wave signal AT THE POWERSTAGE FROM THE EZK terminal. Look at a diagram.

Without special tools like a scope, noid light, LED test light, I wrote that article to go LOW TECH. Pop the cover off the EFI relay and if the fuel pump contact closes WHILE CRANKING you DO HAVE A CRANK SIGNAL!!!

You need to revisit the car and figure out which signal is missing where and why.
ZVOLV is offline   Reply With Quote
Old 11-29-2016, 02:39 PM   #7
greasegram
Member Board
 
greasegram's Avatar
 
Join Date: Dec 2015
Location: kelowna, bc
Default

Talked to my local Volvo dealer yesterday about this issue, and they gave me a new CPS. Now the car runs perfectly again. EFI relay is fine. I drove it a ton yesterday and this morning, and it hasn't died. I'm almost hoping it dies again so i can get to the bottom of this...
greasegram is offline   Reply With Quote
Old 11-29-2016, 02:45 PM   #8
ZVOLV
<Master Tech>
 
ZVOLV's Avatar
 
Join Date: Nov 2002
Location: California
Default

I had some odd issues with my 1990 240 where it wouldn't start sometimes. I forget what I did to fix it, but crank sensor was fired at it a time or two with no luck. I think I recall having issues with the ECU/EZk connection. There was a TSB or something for it I heard, years ago, where grease was put down in the connectors. I would make sure no water damage down there and maybe unplug em and wiggle test em when the problem happens, or IF it happens again.

I would be curious to see if you could see a bunk waveform in the crank sensor on the no start.

Something gives me the feeling it's still gonna be the powerstage. Like I said, THE SECOND it happens, jump outta the car and do a spark test. Maybe drive around with the cover off the EFI relay and do the visual test when it happens and see if the fuel pump circuit does/doesnt activate. It will tell you a LOT with NO tools. Good skills to have when you are out on the road. I had to fix my car on a date with a lady recently. Just a busted stim wire to the alt. Fixed it and got laid!
ZVOLV is offline   Reply With Quote
Old 11-29-2016, 02:54 PM   #9
greasegram
Member Board
 
greasegram's Avatar
 
Join Date: Dec 2015
Location: kelowna, bc
Default

Nice work! I hate throwing parts at things, but when it's free, i can't say no. I'm talking to my snap-on rep right now about getting a demo on his fancy scope right now, so i can test all that. When this happened a month ago, i tested for spark and i was getting it, but didn't check it this time. I did check the fuel relay following your guide when it wouldn't start, and the relay is fine.
greasegram is offline   Reply With Quote
Old 11-29-2016, 03:16 PM   #10
ZVOLV
<Master Tech>
 
ZVOLV's Avatar
 
Join Date: Nov 2002
Location: California
Default

Don't get the versus pro scan tool. It crashes.

The modis ultra worked well for me, but only two channels and not much buffer memory.

I have my cheapo hantek but really want a $1k+ picotech.

I would prob recommend getting a standalone scope unless you really need a snap on scan tool already for otherthings. I need one. II'm trying g to get a mobile tech gig going.
ZVOLV is offline   Reply With Quote
Old 11-29-2016, 03:30 PM   #11
greasegram
Member Board
 
greasegram's Avatar
 
Join Date: Dec 2015
Location: kelowna, bc
Default

I'm 17, so no fancy tech for me yet. I've became buddies with the snap on guy over the past couple years, and has offered me to demo some of his expensive tools, if i need them. I've used the versus pro before at school, and had good results. The local snap-on guy is awesome, and gives good deals so i like to support him
greasegram is offline   Reply With Quote
Old 11-30-2016, 11:20 AM   #12
ZVOLV
<Master Tech>
 
ZVOLV's Avatar
 
Join Date: Nov 2002
Location: California
Default

I like the snap on scantools with the scopes. I have done a lot of work with them. I just didn't like the Verus because it ran on windows XP and it always crashed. I want to play around with the new big screen one! The Verdict. But for the money, I am not completely convinced they are best bang for buck.



Here is a thread with some of my waveform experiments:

http://www.forums.turbobricks.com/sh...d.php?t=313652
ZVOLV is offline   Reply With Quote
Old 11-30-2016, 04:48 PM   #13
greasegram
Member Board
 
greasegram's Avatar
 
Join Date: Dec 2015
Location: kelowna, bc
Default

So, same problem persists with the new CPS. I disconnected the battery, and reconnected it, and it fired right up. I've been test driving it, and it hasn't died yet. Is there a chance this has something to do with the ECU/Ignition controller? I haven't had a chance to use a scope yet.
greasegram is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 09:37 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.