Ritchie Rich!?

[Prof]

From memory mine started at about mid to high 20\'s and went to 86 during the warmup.
 
Not sure if you\'ve tried this, but did you disconnect the battery and leave it 10 or so seconds and then reconnect - that should clear the codes out of the old ECU if there were any, and let it find it\'s own way again with the eManage out of circuit.
 
One other question - what release of firmware are you using in the eManage - there was a lot of problems with early releases - I have 2.11 in mine at present, and I think 2.13 is available now (eManage Ultimate) - not sure if you have the blue one what versions they are on.  I would recommend the Ultimate over the older blue one in any case, as it has much better control for rotaries.

[BenLewisMav]

I have the ultimate, with the latest firmware, 2.13. So theoretically that shouldn\'t be the problem.
 
I\'ve read over what you wrote in this thread and am I correct in thinking that it was the Intake Air Temp sensor wiring what was causing the problem? [that it thought it was hotter/cooler than it was and therefore injected too much fuel?] And that the device you are creating will stop the signal resistance changing?
 
 
I also read on a US forum that people found that their ultimate stopped overfuelling when they disconnected the injector ground (but then had no control over it). Sadly nobody seems to have posted up the results of how they fixed it, and many more sold the ultimate on to buy a microtech!

[Prof]

I\'ve read over what you wrote in this thread and am I correct in thinking that it was the Intake Air Temp sensor wiring what was causing the problem? [that it thought it was hotter/cooler than it was and therefore injected too much fuel?] And that the device you are creating will stop the signal resistance changing?

That\'s basically it - the Engine air intake signal (the sensor on the throttle body, as that\'s the one I have wired up as it\'s more useful) was being loaded by the eManage and this makes it read \'low\' on the temperature - upto 40 degrees low - which means a lot more fuel get\'s chucked in
 
 

I also read on a US forum that people found that their ultimate stopped overfuelling when they disconnected the injector ground (but then had no control over it). Sadly nobody seems to have posted up the results of how they fixed it, and many more sold the ultimate on to buy a microtech!

The way I wired the loom, I could disconnect ignition and injectors seperately and wire them back to the stock ECU - it still ran rich when the only wires attached to the eManage were the sensors - so the problem isn\'t with the injector outputs (the ultimate was reporting 5.7% in and 5.7% out for fueling on idle, so it hadn\'t altered the signal itself)  The one guy with an MX5 did get this to work.
 
The issue seems to be the impedance of the sensors in the old system - which are several tens of Kilohms, and the relatively low impedance of the inputs on the eManage (about 140K), so they create a significant load.  More modern ECU\'s and sensors are probably less effected because they can work with much lower resistances and still be accurate.  It doesn\'t help that the sensor devices are logarithmic, so the errors are worse at one end of the temp scale.
 
These were the voltages with the eMange unplugged:
 
Air Flow Meter: 3.98
Intake Air 4.36
Water 2.72
Boost 2.31
 
 
And the same signales with the eManage connected:
 
Air Flow Meter 4.03
Intake Air 4.23
Water 2.71
Boost 2.31
 
These readings were taken from a cold engine, not started, so they represent the signals the ECU would find on starting.  As you can see, Intake Air temps are reading quite a bit lower than they actually are, and the stock ECU seems to compensate for the \'cold day\' by overfuelling.  Boost signal and Air Flow were measured on the output side of the Ultimate, so these are the signals after they\'ve passed through it - Boost is unaffected (which is how I\'ve set it) and AFM seems to show a slight error, but that could easily be mapped out.

[BenLewisMav]

Ah right ic. Do you think this could still have an influence on the system, even with the emanage unplugged?
I really dont know whats causing it to be so hard to start, the engine was rebuilt 6k ago, so should have good comp, new plugs, completely put back to standard, deflooded and still won\'t start, or at least run smoothly without cutting out..
It also sounds as if the ign. timing is slipping all over the place. Is it possible with no alterations to the ign map that connecting the ultimate has messed with the ign. timing?
Also is there any way to test if the CAS is defective?