MTDI a MK4???

alright... ive got my nomex suit on, ready for the flames...

I want to see an A4 jetta/golf or new beetle that has been converted to mechanical injection.

I searched high and low but found no examples of this being done and i was hoping that someone could point me to a thread or build if it has indeed been done.

YES i am aware that there are very few good reasons to do this, VNT's are more responsive, the ECU will get all pissy, ALH's are great as they are... ETC ETC ETC... That is not the point. I was recently dragged kicking and screaming from my comfort zone of PRE-1999 TDI's because my B4 was just to far gone to be worth fixing anymore.

I am not particularly familiar with A4's other than the ALH TDI but i think i remember that the early MK4 gassers had drive by cable setups VS drive by wire which would mean there are OE parts i could use for pedal assemblies and throttle cables. would this be a viable option for the throttle cable?

I built and ran a mechanical pump on my MK4.Its not on there anymore.I was able to tune it myself and had the engine starting better in the cold and had better boost response with less smoke than the tuned ECU.That was the only 3 benefits to the system.There was less fueling,rpm,timing available.Losing cruise control wasn't a big deal.I wouldn't recommend going with a mechanical pump.

So to be clear I did still run a tuned ecu with vnt turbo etc and just put the mechanical pump on to experiment with.

I modded an old mk4 throttle pedal to do the job and used an mk3 (AAZ) throttle cable.It was alot of work to make the pedal work and I had to remove the return spring from it also as the inj pump has its own throttle return.

Interesting. It's pretty cool that you got better starting and turbo response from a mech pump. You have more mojo than I can dream of. Lol

I have no intentions of going anywhere near as big as your drag car, I probably wouldn't even be pushing the limits of an 11mm rover pump... I was thinking Baja beetle in the 180hp range if I ever decided to try this.

I'm still curious if the early mk4 gassers may have a viable option for throttle cables.

I'm still more likely to do a pickup with an mtdi AHU, always wanted a mini diesel truck... But cheap (sometimes basket case) ALH beetles keep tempting my on Craigslist.

The controls on a 99-03 TDI are virtually the same as your A3 / B4 cars, except they have better diagnostic information available with a scan tool.

-J

Yes, I know. More sophisticated monitoring systems can also be a double edged sword though. Higher repair costs and less diy friendly. Admittedly, the ALH is still rather simple.

My main gripes with the A4 are the smaller interior space - particularly the back seat , the unnecessary immo system, and that awful motor mount in the middle of the timing belt path. Both a3 and a4 require paying - and relying on - a tuner. For most ppl anyway... but at least I don't have to have physical chips burned on an A4.