# "rebuild light" came on...and stayed on



## kismetcapitan (Nov 25, 2005)

well, I trashed my entire injection map today and spent several hours on the road dialing it all back in again. My goal was to get 14.5:1 at idle, 11:1 at 1.9 bars boost (around 4300mV airflow on Z32 AFMs) and basically just to get the whole thing to work.

Had a lot of problems making the map smooth. Some of the transitions were rough, and I had to raise the rpm where the injectors kick in after lifting, because for some odd reason engine braking was a lot more severe than before (could be something else, hope not)

I trimmed the injectors a little, although RC flow tests each set and send a report so I know mine are spot on 1002cc.

But then...THE LIGHT came on. Anyone who has blown an engine knows which light. It didn't flash, and I was stopped at a stoplight - it just came on and stayed on, until I pulled away. I had just started the car a few minutes prior. I stopped, had dinner, then as I drove away, the damned light did the same thing, coming on as I approached a stoplight, and turning off when I pulled away. Never did it again during that drive. I think that's when I raised the rpm setting for when the injectors kick back in to 1500rpm, 1600rpm with A/C on. The car didn't jerk around much anymore with hard engine braking (although why now? I have always used engine braking with my driving technique and never encountered the feeling when lifting the throttle would give a fuel-cut jerk, like hitting a fuel-cut limiter, but not as hard a yank of course).

What on earth would cause the light to come on and stay on?

My fuel gauge is also smoking crack - I filled up 33 liters and the needle DROPPED 1/3rd of a tank.

I wonder if this might have anything to do with it - I found that my left turn indicator (D-speed smoked indicators) up front was filled with about an inch of water (the bulbs still work). I found the leak - the mounting screw is too long and poked a hole in the housing, allowing water to pass through there). I sealed the hole and it's now drying in the kitchen.

I shouldn't be so stingy with the fuel, the car really does run smoother and the knock graph is spike-free, when running richer in the 13s than in the 15s in normal off-boost driving as I had been. My cruise AFR is richer too but no shuffle - so my shuffle elimination was purely ignition timing.

btw, for those who have their fuel pumps running at full voltage all the time off the battery - where's your ground? The negative terminal, or grounded to the chassis?

On the plus side, the car is totally detailed and looks like it's been resprayed. Four nights of rubbing compound and coats of wax seem to have done the trick nicely


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## frostmotorsport (Aug 10, 2007)

kismetcapitan said:


> btw, for those who have their fuel pumps running at full voltage all the time off the battery - where's your ground? The negative terminal, or grounded to the chassis?


Chassis. why?


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## kismetcapitan (Nov 25, 2005)

I grounded to the battery...not sure if that was a good idea...?


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## Rain (Apr 8, 2006)

why would it matter, chassis will have a connection to the negative terminal anyway, all goes to the same place.


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## Sub Boy (Jan 28, 2008)

Rain said:


> why would it matter, chassis will have a connection to the negative terminal anyway, all goes to the same place.


Not sure about fuel pumps and the like....

But with audio amplifiers you should not ground the amp to the Negitive terminal, as it is the "Noisiest" earth in the car (Electrical noise from the altinator)


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