|June 9, 2011 - A-ha!|
Bill and I spent some time on the car last night, and determined that the injector duty cycle is changing when the car goes rich. That means it's not a mechanical problem such as a fuel pump, but bad instructions from the engine computer. We also discovered that unplugging the MAF makes the car go rich, which points towards a real problem with the programming.
After discussing this with Steve from V8Roadsters, it seems that our computer was reflashed for the wrong type of MAF. Unplugging it forces the computer to go back to the static tables, but they're set up for sea level and not 5000' of altitude so they're too rich. To add to the fun, the computer was given a custom operating system so our copy of HP Tuners will no longer communicate with it.
I've been put in touch with the programmer who set this thing up, and hopefully we'll have an answer soon. I've got another track day scheduled for Saturday, and I'd love to have the car on the track in full health. I'm not confident it'll be sorted in that time, but at least we know where the problem is!
entry 859 - tags: conversion, programming