Thursday, 8 June 2017

Mr Cockup returns for a late encore

The chap from Emerald connected up to my PC (amazingly,  this all worked first time) but he noticed an immediate problem with my TPS signal - it was showing a value of 420 at zero throttle when it should have been around the 200 mark. Also, it initially DROPPED to 410 as I pressed the accelerator before rising up to about 600 - it should go up smoothly to a maximum of around 900.

I had a panic attack about having to spend £70 on a new TPS and wait days for it to be delivered. After much panic Googling and posts on forums,  another bloke at Emerald suggested it was more likely to be the wiring to the TPS plug (Simon also said this). 

At first,  I just couldn't understand that; the engine started,  ran and idled pretty well -  surely if the TPS wiring was wrong,  there would be more obvious symptoms? 

There  are only 3 wires into the TPS plug; ground,  positive 5V from the ECU and the signal back to the ECU. Could I be that stupid to get them wrong? Well,  a few tests with a multimeter gave me the answer.  I can't remember where I got the TPS pin layout from but it was obviously wrong. Half an hour to redo the wires and now, 180 to 850 showing in the Emerald software - what a relief! I don't need this sort of panic so close to IVA. 

I was at least able to confirm that my map switch works - got it flicking between a power map and another map that will be the emissions when I upload that (Simon has sent it to me). I've got some instructions from Simon and Emerald to help fiddle with the map when I have the car connected up to a gas analyser (booked in for Saturday before IVA - first weekend day I could get). 

Went for a drive up the road - still no self-centering of the steering and getting a little concerned about that now. I'm going to check the front ride height (maybe it could be lowered although not sure if that will help) and might drop the tyre pressures a little (20 psi at the moment,  18 psi is a common setting but I don't know how much difference that will make). Last resort is to try adjust the front tie rods for some more toe-in and maybe loosen the steering rack even more? 

11 days to IVA... 

No comments:

Post a Comment