Curious ECU problem

[papak]

I have a Typhoon 2 ECU running a 2.3l Duratec in a new Birkin. We conducted a series of initial tuning runs to improve from the base map and ran into a few problems. It turned out that the cams were off by 8 degrees (my dumb) so I had to halt the tuning process and remove the front cover to resolve this issue. At this point, I coincidently discovered a pinhole leak in a corner weld on the fuel tank. That really brought things to a halt. All of this was resolved last week. When we started to work on the tune again, we ran into a new problem, the current issue. The engine starts and reaches a brief 1000rpm or so and then shuts down due to the ECU fuse blowing. I have been working with Tom Carlin on this as well as Simon at Specialists Components. The current thinking from Simon is that either the alternator is causing the problem when it kicks in or the base map is corrupted, allowing the coil dwell to increase dramatically (apparently this can drive the load up to as much as 31 amps according to Simon).

 

I removed the alternator to have it checked (tested on spec) and discovered that the exhaust gasket wasn't sealing well at he bottom of the #1 exhaust port. I was getting a fuel-rich load of soot and apparently hot gases) blowing onto the diode area of the alternator. I replaced the gasket with a new one, with a thicker, more compressible inner layer and it seems better so far.

 

I have visually checked every wire in the ECU harness as well as the continuity of all that I can access. In the course of the cam adjustment, none of the ECU wiring was modified or touched. This one is really puzzling. We didn't have this issue prior to readjusting the cams. It ran, although lumpy and rough, as long as I kept blipping the throttle but not now.

 

We plan on loading a fresh map on Monday. If that doesn't do it, I am ready to extract the entire ECU harness and ship it back to Tom. He is as perplexed as I am. I won't be able to do much until Monday but am open to any ideas on how to resolve this.

Edited October 29, 2016 by papak

[fastg]

What size fuse are you blowing?

 

Graham

[papak]

15a as required by the ECU manufacturer. I eliminated the alternator as the problem today. I'll delete and reload the base map tomorrow and try again.

[papak]

Reloading a fresh base map solved the blown fuse issue. Go figure. Now back to tuning.