UPDATE: this is expected behaviour with the Greddy piggyback EMU + Karcepts tune.
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Well this is frustrating. For some time now I have been dealing with a slight hesitation at particular throttle positions. It's most noticeable coming on/off the throttle when changing gears.

I thought I had narrowed it down to the TPS, as the position % read-out looks like this:



That dead spot at 78% seems to be the obvious culprit and I'm sure that's not normal, right? Anyway, I ordered a new Skunk2 TPS and just installed it. Sure enough, exactly the same behaviour with this new TPS.

So there are a couple conclusions:
- this behaviour is *normal* (doubtful)
- the issue is somewhere else (ECU?)
- my car scanner app or OBD2 reader is faulty? (also doubtful, as the read-out backs up the car's actual behaviour)

This is an AP1 and I have a Greddy Emanage piggyback ECU (tuned by Brian at Karcepts). I suppose I need to disconnect this and see if it's somehow responsible.

I would be very grateful for some smart people to weigh in here. Anything else I should try?

 

I would bypass the emanage just to rule it out. I did the same when I had a misfire I was diagnosing. Can just pop off the kick panel, unplug the connectors from the emanage and then plug them back into the ECU to bypass it. A bit annoying but does not take too long. I doubt it is that but best to rule it out up front.

 

It's the emanage. Stock ECU gives me a smooth TPS reading up and down.

I flipped the dip-switches on the emanage all back to their 'down' position as well (which is the map for sub-93 octane I believe), and no change.

I don't even know what this means. Is my ECU unhappy with the emanage? Is there a bug/misconfig in the emanage mapping? Maybe the harness (for the emanage) has a bad wire? God, I hope that's not it.

What kind of troubleshooting can I do at this point?

 

Well keep in mind the emanage is programmed to alter the signals to the ECU so I cannot say for certain if how it is behaving is normal or not. Given you do have a drivability issue too it seems like it could be related. I would take your data and email it to Brian and see what he says. he can for sure confirm if the signal you are seeing is expected.

I have heard of people having hardware failure of an emanage, but honestly not anyone I really know well. And typically it was an all out failure of something, not an odd signal like this. Brian is pretty helpful and responsive so I am sure he can help shed light on it.

As for the switches, I think only the ones he sold in CA (unless specifically requested) had the 2 maps. The dip switches do not do anything on mine.

 

So that does appear normal, at least with the emanage and tune from Karcepts. Below is the output from mine.

 

@engifineer, thanks so much for checking that.