Crank Sensor?

[jluis]

I removed mine without removing the dipstick pipe,however my pipe had what looks like a factory made dent in that area.

Removing the pipe is just a matter of undoing those 3 screws at the bottom.

If your oil level is bellow max then it won't spill oil.
Just be sure to remove the dipstick before removing the pipe to reduce driping.

The screw that sits at the back of the pipe is a real pita to get to.
I had to use an extension and one of those adapters for variable angles.

 

[saintetienne]

Chaps,

One for the engine gurus out there..

I've had an intermittent problem with my car where I get a flat spot that seems to last from 2k RPM up to 5k RPM when all of a sudden the engine comes alive again and pulls strongly.

If I put my foot down, once above 2k RPM I can play with the throttle pedal but it seems to have little effect on my rate of acceleration nor engine noise/effort/rpm. It's almost like it's not letting the throttle open fully until I hit 5k RPM.

In the past 12 months I've had replaced all the knock sensors, lambda sensors, 1 coil, plugs, filters, MAP sensors, turbo pipework and dump valves.

The car has no CEL's, no errors in the ECU at all and the engine runs faultlessly (no smoke, no misfire) apart form this annoying (massive) flat spot.

A colleague and I were staring in the engine bay at work today discussing what on earth it could possibly be (we've ruled out an air leak on the turbos as it's producing the right amount of boost (around 0.7bar peaking at 1.1bar)). He seemed convinced it's more of an electrical problem than a mechanical problem, and I'm starting to agree with him. He then suggested I double check the MAP sensors because if there is some kind of discrepancy there it could be causing all kind of issues with the electronic throttle and ignition.

Well I've put the multimeter across them and they're reading the right values within the tolerances given in the book of words. I then decided to start going around all the connectors trying to find anything amiss.

That's when I got to the crank position sensor.. the book says it should be 650ohm (which seems around normal for a lot of these sensors..approx 500ohm). However I got 1300ohm which seems way out to me.

Now I always thought a crank position sensor would cause a misfire, or failure to start, or a sporadic RPM dial.. none of which I have.. however it's clearly out of spec and could therefore be feeding the ECU duff information.

What do people think? Have I found my culprit?

Looking for a replacement (as it's clearly not right) Eurospares are out of stock (and I bet this will be another discontinued part!) but stumbled across this 1999 Fiat Punto 1.2 crank position sensor http://www.ebay.co.uk/itm/Engine-Crankshaft-Position-Sensor-Fiat-Punto-Panda-Doblo-Cargo-Bravo-Brava-Crank/331315598390?_trksid=p2141725.c100338.m3726&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20150313114020%26meid%3De57b709acf4b43309259ceaa627945ae%26pid%3D100338%26rk%3D12%26rkt%3D19%26sd%3D291239967479

At first glance it looks identical to whats mounted to my 3200; what do you think the chances are that this is exactly the same part but in a Fiat box??

Cheers

Mark

Here you go Mark

 

[mchristyuk]

Interesting.. yours is quite high too!

I wonder if the spec changed over the years and the book of words was never updated??

Mark

 

[mchristyuk]

Jorge,

Out of interest, the spare you have out of your car.. is there any chance you can put a multimeter across it?

Cheers

Mark

 

[saintetienne]

I changed mine a few years ago as it appeared to have a hot start issue when both fans were on flat out - didn't make any difference !

 

[jluis]

I get 1100 to 1200 ohm as well

 

[mchristyuk]

HAHAHAHAHAAAAAA!!!! SUCCESS!!! I think...

1) Took all plugs out to examine them.. all looked perfect.. slight grey tinge to them all.
2) Checked plug gaps, all perfect.
3) Sprayed contact cleaner in the TB.
4) Sprayed contact cleaner in all connectors I could find under the bonnet.
5) Did a Throttle Pedal reset.. went for a drive.

No bl**dy different.. still felt flat.. but something did strike me, when in Sport mode I couldn't get the gearbox to "kick down" as often as I thought it should.. instead it stayed at the low revs and just tried to pull itself up. Hmmm.. why's it not "kicking down"?

1) Read internet.. pedal should be 350~600mv at idle and 2900~3700mv at the top end, BUT.. the ECU will reduce that to a minimum of 2900mv if it doesn't see full throttle on a trip over time.
2) Check my pedal (again) and had 380mv to 3100mv which is within spec, but at the low end of all the acceptable values and it wouldn't be long before the "full throttle" value was at the minimum 2900mv.
3) Moved pedal arm one spline on the pedal pot.. values now go from 560mv to 3200mv.
4) Decided I'd like to see my top end getting nearer 3700mv so undid the stop screw on the pedal and took it in 1 TURN... 1 TURN..
5) Noticed now that the pedal "clicks" like a traditional auto pedal should click at full throttle..
6) Max voltage is now 3650mv.
7) Did a Throttle Pedal reset.. went for a drive.

Initially didn't feel massively different.. but hit sport button and "clicked" the pedal at full throttle and.. WAHEY!!!.. we're off... and when it changed gear it didn't bog down and just pulled. Each time I hit the pedal now the gearbox "kicked down" and she set off like a scolded cat.

So whilst I'm a happy bunny now I do have a couple "observations" that I'm questioning...

1) Should the pedal "click" at the bottom of it's travel like every other auto I've ever owned? (This is an auto BTW!)? I've shone a light up in the footwell to try and see what is "clicking" but there's just too much in the way and I can't see anything... it's a noticeable "step", I don't know if it's the mechanical linkage going "over centre" OR if it is pressing some kind of button up there.

2) Is the rumour of updated ECU software for the throttle pedal between early 3200's and later 3200's true? My old 2000 3200 which was not OBD2 compliant suffered from a real on/off throttle pedal and was tricky to manoeuvre no matter how many resets were done on it.. and it did get worse over time! I understood why people said 3200's were a bit snap happy on the throttle. My current 2001 car has OBD2 and the throttle has always felt as docile as a kitten (in comparison!) with two different pedal pots.

The throttle stop screw had the factory dab of yellow paint on it that showed it had never been adjusted, so has been like this since new...

Mark

 

[Contigo]

Later cars have a smoother throttle response. Do yourself a favour mate and go contactless TB and Davy's pedal sensor. It transforms the car.

 

[saintetienne]

+1 , my manual throttle was like an off switch prior to TB upgrade , now much more progressive.

 

[mchristyuk]

Chaps,

That's the thing, my throttle has never been on/off and has always been nice and progressive (unlike my old 3200)... just perhaps a little too progressive!?.. It idles perfectly and responds smoothly to inputs so considering it's due a Cambelt/Waterpump service now I think I'll be holding off the TB upgrades until the new year.. unless my lottery numbers come up

Phil, out of interest.. does your Auto have a "click" at the bottom of the pedal travel like a "step down" switch?.. If not I may go back half a turn on the stop screw in case something is going "over centre"...

Cheers

Mark

 

[Contigo]

Chaps,

That's the thing, my throttle has never been on/off and has always been nice and progressive (unlike my old 3200)... just perhaps a little too progressive!?.. It idles perfectly and responds smoothly to inputs so considering it's due a Cambelt/Waterpump service now I think I'll be holding off the TB upgrades until the new year.. unless my lottery numbers come up

Phil, out of interest.. does your Auto have a "click" at the bottom of the pedal travel like a "step down" switch?.. If not I may go back half a turn on the stop screw in case something is going "over centre"...

Cheers

Mark

No weirdly it has a click at the top of the pedal!!!! Not like a step down (that's more of a notch down) this is like a microswitch feel.

 

[mchristyuk]

No weirdly it has a click at the top of the pedal!!!! Not like a step down (that's more of a notch down) this is like a microswitch feel.

Bizarre. Looks like yours is permanently in kick down mode then

Mark

 

[Contigo]

I do subscribe to this paradigm.

 

[davy83]

Hi Mark, great you are finally having fun with your car, sounds like its been a while. There are no microswitches for kick down so the clicking feeling is probably the insides of the pedal sensor hitting an end stop. The voltage values you had initially should have worked fine, so this would suggest that the pedal reset, or calibration was not accepted by the ECU, so you were not recalibrating, like you thought you were? The gradual reduction in the full throttle voltage is internal to the ECU, so the only way to fix that is a pedal calibration, moving the pedal would not fix that. So you have a collection of odd things going on there. How long were you holding the pedal at full throttle for the calibration? the book says 5 seconds but i reckon closer to 10 is more reliable?
There are a couple of reasons the ECU will ignore an attempt at re-calibration, one is if the voltage is outside the acceptable range, second is the voltage moves during the calibration, and third is the two outputs are different from each other by more than a certain amount around 30-50mV. Any chance you had on of these going on and the pedal sensor calibration was not accepted?
I mean if it works now, like the man said drive it like you stole it, personally i would back it off until the clicking stops . did you look at the voltage from the sensor while pressing the pedal, does it increase smoothly all the time the pedal is moving?

HAHAHAHAHAAAAAA!!!! SUCCESS!!! I think...

 

[mchristyuk]

Hi Davy,

Understand regarding the gradual reduction, what I was trying to say was that my initial values were not far off the absolute minimum the pedal would ever get reduced to anyway.. so wanted to give it some head room as it were "just in case" things were a bit temperamental (it is Italian after all!).

I did check the voltage whilst moving the pedal and it was smooth.

I've reset the pedal on my old 3200 more times than I care to remember and never had a problem with it accepting it.. perhaps this one is just that bit more picky! I do make sure full throttle is kept down for at least 10 seconds.

One thing that is never clear about the calibrations though is whether we should wait for the ECU red light on the dash to go out before starting.. like we would before cranking the engine over to start. What are your thoughts? Wait for the red light, or not before pushing the pedal down and starting the clock?

Maybe the pedal pot tracks were a little worn and when holding full throttle were varying by more than the 50mv and moving the arm around one spline has just moved it off that spot and is allowing the calibration to be accepted?

Cheers

Mark

 

[davy83]

Wait for the lights to go off or not, before pressing the pedal. i have failed and succeeded doing both of these so i don't think it matters. I think the 5 seconds starts some time after all the lights go out which is why i reckon hold it a bit longer to be safe. Yes i think maybe a bad spot in the carbon track around your full throttle location might give you this problem where the full throttle calibration was rejected. I always assumed it used the last good calibration in this case, but i am wondering now if it adopts a default which would maybe mean you never got close to full throttle because it was a voltage way above anything the sensor was putting out, as you say it was close to the lower limit? hey it's Italian.