Checking all the sensors on the t-spark

[Joss]

As I'm putting the 155 back on the road I need to sort out a couple of problems. As mentioned in other posts I've got elect problems which will hopefully be solved by the drying of the fuse box. I've got a bit of a rough running problem when cold. Now I changed the MAF a while back along with the Cam sensor and Lamda sensor. But as the cars has been parked up for so long I think they could be creating the fault. the injector light is on and I've moved the camsahaft into so many different possitions using the blocks or otherwise that it can't be in the wrong position all the time. I know there is a way to check teh sensors with a multi meter but what should I be looking for accross the pins. (resistance, non) ETC. Is teh injector light like the MSCF light on newer alfas. meaning it could relate to a number of problems or is it just injector system and cam timing?

Cheers to all

[Thompatruck1]

To check your lambda sensor....unplug it, should be a plug on the back of the engine poss on the bulkhead (on a 155 its under a plastic cover) 4 wires in it 2 will be either black or white do a resistance reading across the two wires they should give a reading between 3.5-5.0 ohms anything outside of that at it's probably knackered

Cam timing sensor, Not sure how to check the sensor but were you careful when tightening the exhaust pulley? reason I ask is once I tightened the pulley and damaged the sensor ring on the inside edge (bent it!) which when the engine was spinning at x'000 rpm killed the sensor, if you've done it that many times it could have damaged it

The injector light on a 155 covers a whole load of errors on the fuel mixture side of the engine, lambda, injectors, afm, water temp sensor...... although don't quote me on that!

HTH

[pull]

I had similar probs, mine turned out to be the lambda. Whilst I was at it though I also cleaned the ICV, MAF and replaced the temp sensor (one on the thermo housing), she ran like new and the annoying little injector light went out :-). Might also be worth running some home-made injector cleaner through - there is thread on here somewhere about it, 500ml of parafin or the similar, people have had great success with it and at a fraction of the cost of shop stuff.

[Joss]

I replaced the lambda a while back as the wires were all broken but it didn't show a fault at the time. The cams have been out of this engine upteen times so I bet its got damaged. Bit of a shame as the sensors are 100 quid new. Might change the temp sensor as that s never been done to my knowledge. I'll stick the cleaner in too.

Does anyone know the resistence accross the cam sensor. I found it once but that was a long time ago

[celadon]

Not sure, but I have an engine out at the moment, and the sensor was ok, I'll check the reading for you if you like .

[Joss]

Wicked. If you wouldn't mind mate. No rush, Just tell me what it is next time we're online Forzaring!

[celadon]

No probs,

I'll be doing lots of work on her at the weekend, i.e putting engine back in

Going to replace all the clutch components including master cyl + slave cyl,
Had a look at the master cylinder, and can see why it is such a job to do with the engine in, as it looks like a right PITA with the engine out !!

Gonna clean up the gearbox a bit - inside and out - before it goes back on.

Really miss driving her

[Joss]

Cool. yeah good shout on doing both. I had the slave go a while back. Everyone said the master wouldn't be far behind and suprise suprise it went a week later.

[celadon]

Thats exactly what I thought, although my slave has been 'fixed' a couple of times.

I already had a replacement slave ready to go on the next time it failed, and I checked the seals the other day, and they were pretty close to going again.

As I was going to be putting a new slave on, the thought passed through my mind that it may put extra pressure on the master, and for the cost of replacement, thought to do it with engine out of the way.

[celadon]

Tested the sensor, but got no readings at all.


Checked the manual to find out why :-


"The cam angle sensor (timing sensor), supplied at 5v by pin 12 of the control unit
and sends a signal in frequency corresponding to the phase to pin 8 of the control unit itself:
These two signals are very low in intensity and are therefore suitably screened.
The sensor comprises a Hall effect device due to which the voltage signal sent to the control unit
'lowers' abruptly when the hollow machined on the camshaft passes in front of the sensor."

Ie, no resistance reading.

[Joss]

Awesome. cheers for that mate!

[Thompatruck1]

If you need the cam sensor, I might have a spare it would save buying a new one, if it's any use let me know and i'll have a look