How to tell if timing sensor needs replacement

[ehoe]

To all the sifu's out there, does the timing sensor on our UDM has a 'life span' or it is one of those parts that is suppose to last the life of the car?.I ask coz I read somewhere that some of the symtoms of a weak timing sensor is like hard to start the car (needs a few cranks), bad idling, lost of power, etc. Anyone know what are the symtoms of a failing timing sensor?BTW this is for a friends M20B20.....

 

[bmwky]

if you mean the pulse sensor. you can check the impedence of the sensor. It should read btw 540+-50 ohms.

when it is going bad it will produce the symptoms as described.

 

[WhiteTip]

Not sifu but life experience on my M20B25.

I dun feel the lost of power, no idling issues. Only problem is intermittent starting issue.

Systoms is simple. Most of the time you have no problems on starting the car. Then out of 5 - 10 times you will have diff. to start the car (few cranks). Later stage the problem become more rampant....

Change the timing sensor and it solved. About RM 450 if i am not wrong..

 

[moots]

Here's my personal experience:

1. hard starting -> 4-5 seconds to start in the morning one day on my way to work when normally it takes just a crank
2. reached office.on way out for lunch-> unable to start
my trouble shooting:
1.chk for fuel from hose into fuel rail whilst cranking- nil fuel
2. went to give a few thumps at the fuel pump in boot - nil joy
3. chkd fuel pump connector for dirt - ok
4. swapped fuel pump relay with other adjacent relays - nil joy
6. called Kenny from M Speed and he said to chk for spark at plugs.if nil,could be CPS(crank position sensor) - confirmed nil spark
7. i straight away disconnected the CPS connector and confirmed the reading at 8 megohms.per Haynes manual it should be 500-600 ohms
8. went on to buy the CPS at Autobav PJ at rm 240 i think (definitely not > rm300) and fitted - presto start at first crank. :yes!:

this happened about a year ago........

 

[ehoe]

Thanks to all the sifu's that replied. Am experiencing some of the symtoms as described by you all so I guess my CPS is really getting weak. Time to get it replaced, hopefully the price is a lot cheaper now. :huh:

I know several years ago I had a much worst problem, the car bad ilding and felt like it was misfiring. Refused to rev despite pressing on the gas pedal and this was an intermittent problem. Later found out that the CPS (aka timing or pulse sensor) was rubbing againsts the pulleys/belts and the cable had been partially cut thru!. So for those changing their CPS, better make sure the cable is securely fastened and not rubbing against anything.

Tks again to all.