After driving my 4ktq for a while with the stock 5kt CIS fuel system, I came to realize that 'tuning' and 'CIS' are two words that don't belong in the same sentence. When my fueling needs changed, CIS could not put out the kind of smooth fuel delivery that I needed. I decided that EFI was definately the way to go.

After doing a little research, I went with 034 EFI as my system of choice. The price was lower than some of the alternatives and Javad had it up and running on his 80 turbo quattro. I decided that when I ran into questions it would be best to go with a system where someone would be able to help with information specific to the Audi I-5.

As far as the modifications necessary to make this system work, most of the sensors were fairly easy to mount. Nate Stuart has an excellent page up on his website listing the required inputs and outputs for this system. The setup on my car is very similar with a few differences.

I used the same Ford TPS as Nate, but mounted mine using a bracket that I welded together (he used a plastic plate).

On the fuel injectors, I used a set that I bought off ebay for ~$60 for a set of 6 that someone was using in a custom GMC Cyclone that were rated at 34#/hour. I may be upgrading these as I'm noticing that I'm running in the 90% duty cycle range at WOT, so I don't have as much injector 'headroom' as I would like. The great thing about EFI is that it is no big deal to go with bigger fuel injectors or some different type of just about any component for that matter.. just update the software settings to compensate!

On the ignition side of things, the EFI computer expects 5 pulses per cam revolution. On the MC distributor, there is only one window which means it pulses only once per cam revolution. The reason for this is because on the MC, the ECU counts the teeth on the flywheel to get the rest of the engine positional information that it needs. Granted you can install some kind of timing pin setup with a hall effect sensor to produce the desired pulses, but after fabricating such a beast I decided I did not want to go this route.. it just seemed a bit hackish to me to strap another timing device onto the engine. Plus it would have been a pain to come up with a cover to go over the pins and fit any kind of front mount intercooler at the same time.. Because of this I decided to rip out the MC ignition system and run with the type 89 ignition system which produces the 5 pulses per revolution that I needed and also makes use of a knock sensor. I have a separate page on my website that describes this swap. As an update, I later found out that Nate used the MC ignition system without the need for timing pins! His solution was to try and use the coil trigger pulse instead of the signal from the distributor. The downside to doing this is that the coil pulse could be considered somewhat late in comparison to the distributor pulse, as well as the fact that the ignition ECU constantly varies the advance/retart which would throw this input that much further off from the actual individual cylinder TDC event that is needed. Nate reports that despite this the engine runs great using this method. This is probably due to the fact that the fuel system in general is very tolerant to when fuel is delivered since the intake valve is only open for a brief period of time and it is perfectly acceptable to fire an injector at a closed intake valve...

After I had everything up and running I had to make a few mods just for fun. To give myself a 'heads up display' from my ECU software, I installed LCD screens in the sun visors and hooked them up to an AV box that lets me display the screen of my laptop on them. I have another page on my site that describes this mod a bit more, but here are a few pics:

Another fun thing about a programmable EFI system is the ability to log the running parameters of your engine and use them to fine tune the system. Just for fun I put up a page on my website where I download the logs and feed them to a script that parses the data and creates a graphical representation of the data. You can check it out here.

After having completed this conversion I think it would actually have been EASIER to go with EFI right from the start with my turbo conversion. It was more of a headache just setting up the MC wiring harness in my car than it would have been to adapt the 4kq ignition system to work with the EFI setup.

Well, that's about it for now. I have a whole pile of pictures that you can view in my image gallery.

Next mod: Exhaust header :-)