How would I know - IT needs fixing !!

[Cressidom]

Seeking advice from the pro's on the following..

1 ) oxy sensor shot - what are the symptoms ?

2 ) MAF shot - what are the symptoms ?

3 ) Crank or Cam Sensor shot - what are the symptoms ?

4 ) Throttle switch shot - What are the symptoms ?

How do i find out the above are not in 'normal' function ??

Thanks all
Dom

[shogun]

you have in my opinion 3 options:

1. Go to the dealer and ask for a diagnosis readout and then come back to us, so that we can help you from there on.

2. buy a PEAKE fault code reader, which on the long run will save some money
http://www.peakeresearch.com/

3. Buy a Bentley Repair Manual for the E34 whre all technical data are inside so that you can check these parts and how to check them.

Without these "tools" it is just searching for a needle in a haystack.



Even if we tell you now each symptom, it is not 100% sure that really these parts are damaged. You have to check them anyway before buying expensive new parts.


How do i find out the above are not in 'normal' function ??


The only good way is measuring them. The oxy sensors your can check with a voltmeter for example to find out if the voltage is frequently changing etc.
And for the rest you also need the data from the Bentley.

In general the symptoms will be:
hesitating, surging, running rough, erratic idle, hunting idle and stalling when accelerating.

[bagpuss]

Seeking advice from the pro's on the following..

3 ) Crank or Cam Sensor shot - what are the symptoms ?



when my cranks sensor went, it would not start.

[Flamin'Cow]

would it still turn over tho?

[DaveVoorhis]

would it still turn over tho?
None of the sensors you mentioned would stop the starter from running.

[GoldenEagleFan]

As long as the battery and starter are fine, the car should turn over. When the crank sensor is out the "brains" of the system can't figure out where TDC of a designated cylinder is so it doesn't know when to fire off the fuel injectors or spark at the correct time, hence it ussually doesn't start and if it does it runs like crap and usually kills quickly.

[SnakeyesTx]

Seeking advice from the pro's on the following..

1 ) oxy sensor shot - what are the symptoms ?

2 ) MAF shot - what are the symptoms ?

3 ) Crank or Cam Sensor shot - what are the symptoms ?

4 ) Throttle switch shot - What are the symptoms ?


1) Crap idle, rich fuel smell out the back, maybe a little even under the hood. -this sensor also trips the check engine light (not the worded display)

2) Really crappy idle(if bad), unplug the MAF, and idle should jump up about 1500 rpm and smooth out (but don't drive it unplugged or it'll stall out).

3) Again crappy idle (may idle fine but read-on), sometimes engine will just shut off while coming to a stop while driving, takes a few attempts to restart car again, may run okay the rest of the day, may stall out again at the next time you stop. If really bad, car won't restart either. This acts like a pickup-coil using a electro magnet for a pulse signal.

4) As in Throttle position sensor? Idle will wander while sitting still, like say from 600-1600 rpm and rev and drop rev and drop. This one you can unplug and hook up a multi-meter and check the resistance sweep from closed to wide-open throttle.

[Cressidom]

:D Thank you all ..great help...I will research more...

:( but ..looks like some of the tips/advice are already happening..so i'll have to troubleshoot 1 by 1 and start eliminating the 'problems'...


cheers all

[ThoreauHD]

1 ) oxy sensor shot - what are the symptoms ?

Fuel mixture rich. Idles rough as hell.

2 ) MAF shot - what are the symptoms ?

Drive for 30 seconds and stalls. Turn on and stalls.

3 ) Crank or Cam Sensor shot - what are the symptoms ?

Don't know. Haven't replaced it yet.

4 ) Throttle switch shot - What are the symptoms ?

Don't know. Haven't replaced it yet.

[Cressidom]

Thanks THD...

work in progress !!

Dom

[Cressidom]

Swapped a MAF from a mates car today....

Problem still there..SO guess it's not the MAF 3 more to go.

Cheers
Dom

[bagpuss]

would it still turn over tho?

Yes.

[bagpuss]

Why not do what someone else has suggested already and read the codes in the ECU ? An Indy will do it for next to nothing - mine charges either nothing or 10 quid. Better than trial and error, it should take you direct to the fault.

[Cressidom]

Thanks puss...I have made an appointment for a MODIC check this monday..
will know for sure then.

Cheers
Dom

[bagpuss]

If car still runs and its a recurring fault and you havent had the codes reset for some time, it would be a good idea to clear the codes first (so any old, irrelevant codes are cleared out of the way so not to mislead the diagnosis) and let the 'real' code appear after the code reset. Chances are if you dont do this first, the mechanic will clear them for you then ask you to come back. If car not running, ignore this advice, but if it is, you can clear codes by pulling the ecu out for a while or by disconnecting the battery for half an hour and touching the + and - together before re-connecting. Might quicken the diagnosis.

[Cressidom]

Roger that....

Will clear the faults first...

cheers
Dom