Overfuelling

[Rory's Dad]

While typing this up I have just wondered if I've got the supply to #4 injector and the temperature sensor muddled up.  That would confuse the ecu wouldn't it??  I'm sure I checked it carefully when I put it all together - I'll check it again...

That can't be a possibility - it 'runs' on four cylinders.

Rory's Dad

[Guest]

I think you will have to have the car 're mapped'. The chances of having the throttle butterflies and the TPS in exactly the same position as before is virtually zero.

The ECU needs to be 'set' for your new settings as this is the start point of the fueling maps and will not work correctly unless they are mapped.

There is no 'load' sensor with your EFI unlike a MAF system which actually measures the airflow into the engine.

Your TPS is the only way the ECU knows how much air is going in and this needs set properly in conjuction with your throttle butterfly angle (Did you know what this was before they were stolen - I doubt it   )otherwise the whole of your fuelling MAps will be out.

The throttle bodies will also need balancing as part of the process. You are really wasting your own time by trying to mess around with this.

[Rory's Dad]

Thanks BMS but, with the DTA ecu, the whole point about setting the throttle stops is that the ecu reads the fully shut and fully open positions and recalculates accordingly.

Rory's Dad

[Blatman]

And it will. The point is that the new throttle bodies only have to be eversoslightly different to the old ones for the TPS to be unhappy and make a mess of the readings / voltages it sees. That despite the new bodies being well within any manufacturing tolerances, the upshot is that if the TPS is even a little out, it'll be out all the time. So you need to "re-map" the TPS position in the DTA. I doubt you'd need to re-map the whole thing...

[CedricTheBrave]

are the injectors the correct impedance or same flow rate as before?

[Guest]

Thanks BMS but, with the DTA ecu, the whole point about setting the throttle stops is that the ecu reads the fully shut and fully open positions and recalculates accordingly.

Rory's Dad

I won't say 'I told you so' but how do you know that the throttle bodies at the TPS 'fully shut' point are flowing the same amount of air as before?

[Rory's Dad]

Blatman - this is not eversoslightly its by a huge margin.  The mapping was done by Steve Greenald - the car just went brilliantly from trickling through town to  doing something else on the open road!

DWilkes - the injectors are SBDs equivalent of 744s.

BMS - I don't, but I have got the butterflys as synchronised as possible and they all look equally shut.  The settings (open and shut) are taken without the engine running.

I'm going to check the wiring on the TPS again this evening just to make sure I haven't got the wiper and the 5v supply the wrong way round.

Thanks for all your comments      

Rory's Dad

[Dave Eastwood (Gadgetman) - Club Chairman]

DWilkes - the injectors are SBDs equivalent of 744s.

So not the same then, "equivalent" can cover a multitude of sins sometimes.

Same flow rate, impedance, spray pattern?

[CedricTheBrave]

I would just take it to Steve at Track n road and he will map it correctly for you. for all you know the old injectors could have been poor quality or worn and it was mapped accordingly. and Steve will set the TPS correctly and you will be back to normal.

[Rory's Dad]

I'm going to check the wiring on the TPS again this evening just to make sure I haven't got the wiper and the 5v supply the wrong way round.

Well I had about half an hour to spare and just swapped the wires around and turned the key and it started and ran reasonably cleanly.  AT LAST      

I had turned up the idle screw last time I was at Kevin's and so I turned it down so it was running at about 1000 rpm - which it did more or less.

I wanted to take it for a decent run but I didn't have the time  - or the steering wheel       .  That's tomorrow evening's job.

I'll ask Kevin Brown (my new best friend!) to check it over again and then he said he'd lend me a data logger thingy that plugs into the lamda sensor socket and he can then get a sense of where it is in terms of good settings.  I better go out a get some more beer!

I'll try and fix it this way Mr Wilkes before I work out how I can afford a trip darn sarth  

Thanks again for all your help chaps!

Rory's Dad