No Throttle Response after sitting on a Hill

[Evoluzione]

Just a guess, but if you're making a hill start then the revs will be higher at a given point of clutch travel, the clutch also has a sensor or a switch on it too. That would explain the differences, but not what is happening.
If it's anything like an MX5 (and they are very similar in many respects) it'll have an adjustable clutch pedal. It's an adjustable rod up in the pedal box under the dash, basically undo a small locking nut and turn the other one to adjust the biting point, you never know it may clear the issue or make it worse, but at least if it did it could tell you something. They do come very badly adjusted from the factory sometimes.
I would have a look up into the footwell and see if everything is clipped on and working as it should. I once got into a Mazda with my work boots on and managed to unwittingly snap off the brake light switch. That took some finding as it was a bright sunny day and I couldn't see the brake lights were permanently on, just that the battery kept going flat. It was only when it was pulled into the workshop did I realise.
Sorry I digress If it gets to the point where you need any parts to swap out let me know as i'm breaking one of these, it won't be long before its scrapped though. They're quite a rare thing so good s/h parts are difficult to find sometimes.

[GreenV8S]

imck said:

When the fault occurs the Pedal compared to the Throttle values do not seem consistent to me.
The Pedal % Increases but the Throttle % doesn't.

That's consistent in that both pedal position sensors show readings consistent with the physical position, and the throttle pot position sensor confirms that the throttle is closed, which is consistent with the lack of power. That suggests that these sensors are working correctly and the problem is that the ECU is not opening the throttle. The lack of fault codes suggests it is not even trying.

I'm assuming here that the ECU provides a fault code for the throttle actuator.

[imck]

Thanks for the Ideas.

I work in Electro-Mechanical Repair and usually quite good with Logic.
This just doesn't make sense !!

I had considered replacing the Throttle Body and MAF. Not cheap Parts to throw at it though.
It can be quite jerky in crawling Traffic and there is some hesitation/hiccup at certain Revs.

One of my Colleagues suggested Breather System? I was giving him a lift for a Week and he said he had noticed some Hesitation.
There are some guides/videos for changing the PCV. Intake needs to come off. No idea if this would cause any of the Symptoms I have got?

I can't find a Service Manual apart from a scanned Russian one.

Getting a bit fed up with the Car
The AC only cools for around 30 Mins. Hopefully a regas and Drier might fix that. Suspect moisture/icing
The Wheels need a refurb and new Tyres.
Bought in the Rain and didn't notice a badly touched in scrape down the Side.
Do I spend or move on.

I will order an OBD Adaptor that is compatible with Forscan and see if that gives any more clues.

I might well be interested in the Throttle Body and MAF.
Presuming you are not scrapping due to yours also being an arse

[GreenV8S]

Since I don't understand the mechanisms causing the problem, I'd be inclined (sorry) to try to get more information about what provokes it. Is the slope significant, or just a coincidence that the times you are stationary during your regular drive just happen to be on a hill?

[imck]

GreenV8S said:

That's consistent in that both pedal position sensors show readings consistent with the physical position, and the throttle pot position sensor confirms that the throttle is closed, which is consistent with the lack of power. That suggests that these sensors are working correctly and the problem is that the ECU is not opening the throttle. The lack of fault codes suggests it is not even trying.

I'm assuming here that the ECU provides a fault code for the throttle actuator.

Since I don't understand the mechanisms causing the problem, I'd be inclined (sorry) to try to get more information about what provokes it. Is the slope significant, or just a coincidence that the times you are stationary during your regular drive just happen to be on a hill?

That makes good sense Thanks.

If Pedal Pressed and Fuel Pressure (for example) Sufficient, the ECU opens the Throttle.
If not, the Throttle is not opened.

[stevieturbo]

There will be extensive fault reporting for many DBW problems if something is amiss. DBW is a rather safety critical item

You say no codes or fault lights...the CEL does actually work though ?

But viewing some live data just isnt always enough, especially when some values may be calculated rather than raw inputs.

Add to that, the blade will not always track your foot 1:1, there will be a blade target map, based on pedal position and other factors so this can confuse any readings.

Clutch switch is a possibility, to prevent someone going full throttle with the clutch depressed. Another could be a brake pedal switch for similar reasons.

Not sure of any generic OBD will allow you to view these inputs though. I'd expect a vehicle specific setup should though

[imck]

I have found an English Service Manual and have downloaded.
https://drive.google.com/file/d/0B6ixeaKldj3rVW9Sc...
Page 1133

Very apt Statement in the Manual....
The PID/DATA MONITOR function monitors the calculated value of the input/output signals in the PCM.
Therefore, an output device malfunction is not directly indicated as a malfunction of the monitored value for the output device.
If a monitored value of an output device is out of specification, inspect the monitored value of the input device related to the output control.

Yes. the CEL is working.

There are some reference values in the Manual. The Pedal and TPS values I captured with Torque match them.
I think I need to expand what Functions I am monitoring.
The Forscan App has unit options. Voltage, etc rather than % Values.

I really appreciate your ideas and suggestions. It has made me think about this differently.
Cheers

[GreenV8S]

stevieturbo said:

Another could be a brake pedal switch for similar reasons.

Good thinking. I can well imagine the ECU having an algorithm to limit power when the brakes are on.

[imck]

My New OBD Adapter turned up Today
Used with Forscan. Excellent bit of Software. Can do all sorts with it on my Windows 8.1 Tablet.
Multiple Systems can be monitored including the Brake and Clutch Switches.

It showed an Error Code which does not cause the CEL to come on.
U0140 Lost Communication with Body Module
No indication of when it appeared. I did disconnect the Battery when cleaning the Throttle Body 6+ Months ago.
Cleared along with TPMS Errors (Sensors are on my Bench at Home waiting new Batteries and Valves rather in the Wheels)

The position of the OBD Socket and size of the Adapter means it is a bit too close to my Right Foot to drive safely with it plugged in.
Have ordered an OBD extension Cable.