Thread: ECU Dilemma
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dgarrood dgarrood is offline
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Join Date: Dec 2009
Location: Chelan, WA
Posts: 58
ECU Dilemma

I have a dilemma in that the way forward is not clear to me with limited P-car background. Here is the dilemma but first some background.

I have a 930 converted to "modern" EFI circa 2004, the motor was rebuilt by the PO using first class parts to achieve good street performance but to a budget. The EFI components were chosen to be compatible with the ECU - the DTA P8 Pro which means they are used on Euro cars making some items hard and expensive to get. The car was "street" tuned using a wideband O2 sensor and common sense. The car has seen about 20K miles since the rebuild and conversion. I bought the car about 2 years ago (10K miles) fully knowing the history of the conversion.

The dilemma concerns the ECU: It has no output on one of the coil channels (#4). It took me awhile to figure it out; but when I put the timing light on the wire attached to cyl #4 - nada, no drive either, verified by using an o-scope. Coil ohms-out the same as other coils. So I am discovering that fixing the ECU looks like a non-starter by anyone in the US as the unit is obsolete. I am waiting for a reply from DTA, but not expecting much support. I can purchase a new one for a couple of grand or a used one for maybe half. DO I ABANDON THE DTA, ADD SOME MORE CASH AND PURCHASE AN ECU plus whatever else I need that is supported in the WESTERN USA? Maybe the kit by Clewitt? Opinions are solicited from the forum.

There may be an relatively inexpensive fix to this which involves changing the ignition to wasted spark. This configuration uses channels 1 -3 avoiding #4. I would have to buy a triple dual coil pack, connector and make new HT wires. I understand the performance trade offs made by going to wasted spark; but I have a 400HP car at best so it should be fine. This would get me back on the road; but I still have an ECU with one failure in the coil drivers, who is to say whether more to follow.

Any feedback on any of the issues raised are solicited.

Thanks for your feedback,
1996 993TT Arena Red
1997 993 Coupe C2, 1987 930 Turbo Coupe, 1985 911 Carrera Coupe, 2002 Boxster S Blue (all departed)
Old 06-10-2012, 06:07 PM
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