The Project Pad

DE80q wrote:It actually sounds like the engine needs new rings, that's a lot of blow by to be causing smoke from the exhaust.

Yes, that is the case. But, an engine rebuild will be another project another day. For now I will connect a hose to the intake without a PCV valve to get rid of the vacuum leak. The donor car had a small amount of oil in the cone filter, so over time I am sure some oil would get into the intake without a catch can.

viridia wrote:Run a hose without a PCV. Was using the Urq hose on mine:

Thanks for confirming your setup. That looks like the best solution for now.

viridia wrote:

DE80q wrote:HEY! I remember reading about those fuel lines. How well did they hold up?

Hah, they work just fine. Driven roughly 10k with them, though removed now awaiting the EFI stuff. Had my fun with CIS!

Can I get some more details about this? Looks interesting!

Well, that didn't work. I connected a hose from the intake to the valve cover and got a rough start, rough idle and engine sputtering. When I pressed the throttle I got smoke out of the exhaust and the car nearly stalled. When I put the cone filter back on the PVC valve port and capped the intake port, the car started a bit better, idled nicely and revved well when I hit the throttle.

That reads like the engine has a vacuum leak somewhere else in the breather system. Normally, the crankcase is closed to atmosphere and experiences the same vacuum as the intake prior to the turbo. The only relief to that vacuum is through the CIS metering plate which lifts, allows a certain portion of air through, and allows a certain volume of gas through the fuel metering head.

Could there also be a blockage somewhere in the breather hose system that the cone filter is relieving?

TrailAgent wrote:Could there also be a blockage somewhere in the breather hose system that the cone filter is relieving?

My first bet would be the big hose from the side of the block (driver side)
Either collapsed in on itself or the 'bowl' is full of gunk

I recall alot of people warning about using those with 115 psi of fuel (or whatever max you run). We all secretly wanted it to work for you tho

88a5tq wrote:I recall alot of people warning about using those with 115 psi of fuel (or whatever max you run). We all secretly wanted it to work for you tho

It must be working for me! Cold start is difficult, but once it's started it drives like a rocket! My mechanic is German and used to work for Audi in the 80's. He is a bit of a mad scientist when it comes to CIS. He's confident he can get the cold start sorted out when he has more time. In the meantime, today I got started swapping the power leather seats from the Audi 200 into the 4000. It's the little things...

Untitled by TrailAgent, on Flickr

Untitled by TrailAgent, on Flickr

Untitled by TrailAgent, on Flickr

I need some advice on the exhaust system.

For the swap we temporarily mated the 2.5" down pipe to the stock 4000 2.25" system. It was quieter than a minivan both outside and inside. The stock system had two mufflers.

Today, we replaced the 2.25" pipe with 2.5" and a Vibrant Ultra Quiet Resonator and a Borla XS Pro muffler. The sound is dreadful inside the cabin. Between 2k and 3k RPMs, when you hit the throttle, the sound is incredible deep (like a tractor) and painfully loud. It does not settle down to a nice rumble until you hit 4K RPMs and let go of the throttle.

Does anyone have some advice or recommendation on which muffler (and resonator) combination brings out the nice sound of the 5 cylinder engine, but gets rid of the painful low frequency?

Seems like you need a 1/4 wave resonator to eliminate drone.

Really happy with the Flowmaster 60 Series I just installed on my 7A Coupe GT. No cat, cherrybomb resonator, Flowmaster.

Traced the cord-start problems to the Warm-up Regulator. I think I found the last NOS part in existence in the U.S. at RockAuto.

Got started on new suspension and brakes this weekend. I will be replacing every bushing and bolt. The struts and springs will be replaced with Bilstein Struts and H&R Sport Springs. I'm hoping for a firm ride without the clunking and rattling. The old suspension was dangerously loose.

Untitled by TrailAgent, on Flickr

Untitled by TrailAgent, on Flickr

Untitled by TrailAgent, on Flickr

Wow, what a difference new suspension and tires make. Finished installing H&R sport springs, Bilstein B8 springs and new bushings, bolts, etc. all around. After the alignment, the car feels amazing. I also sorted out the exhaust drone. Turns out that the exhaust tips needed to be extended a bit and the resonator removed. Now, I have just straight pipes leading to a Borla XS muffler. Sounds great and not too loud.

Next week I am tackling the new warm-up regulator, grill and headlights.

Untitled by TrailAgent, on Flickr

Nearly finished fitting the replica grill I ordered from Latvia (cool-wheels.com). Originally, it was too tall because of the stainless metal trim on the bumper. But, with some trimming and cutting, it should mount nicely and hide the intercooler.

Untitled by TrailAgent, on Flickr

Untitled by TrailAgent, on Flickr

Untitled by TrailAgent, on Flickr

sweet project! glad to see others still playing with 20vt's.

after driving a 4.11 20vt car I think that a 3.89 is better suited. to each their own opinion, I just don't like running at 4000rpm all day just trying to do 80mph, especially with all the extra heat that these engines hold. If I lived in a metro area I might prefer the 4.11 but out here in the hot flat desert I want taller gears.

its worth noting that the 5k 20vt had a center locking 016 with 3.89 final. I was trying to buy one from vt10vt but he never got back to me with a shipping quote.

Well, apparently, it has been a few years since I have posted on this Forum. The Audi 4000 20vt has been running pretty well. I've made a few upgrades, such as larger intercooler placed in front of the radiator which allowed me to go back to a stock grill and quite a bit of maintenance. My biggest headache is the CIS (no surprise). This is partly my own fault. The CIS is from an '84 URQ. Once the car warms up, it runs great. But, it has a hard time getting fuel into the engine when cold. So, that begs the question. What would it take to go EFI? I know this question has been asked but I have not found a start to finish write-up on forums. In most cases, the posts are old and no longer available or they contain a few bits and pieces of info.

Is there anyone on this forum I could pay as a consultant to help? I already have the 034 fuel rail and injector inserts. I have a general idea of the other parts I need (injectors, pump, etc.), but getting it all put together and actually running is the part that seems to be missing from my research. Anyone interested?

There are a couple options for EFI comouters. I'm running MS3X on my 20vt, others are running VEMS. The 034 EFI computers are no longer supported by 034, so not much help there any more.

Injectors will be up to what your power goals are. I'm running a set of 440cc injectors from a Volvo. They have an extended tips that works well with the CIS head. You can run the factory pump for quite a while before it runs out. My suggestion would be to remove the fuel accumulator though. With that removed, the pump will respond better.

Let me know if you need any more info. Happy to help where I can.

Thanks for responding. I definitely could use some assistance. I’ll take a look again at MS3X and let you know what questions I have.

Are you using MS3X for both fuel and ignition? My woes appear to be mostly related to fuel delivery. Do you recommend using MS3X for both fuel and ignition right away? If possible, I would like to tackle fuel now and consider ignition another day.

I'm using the MS3x to run full sequential fuel and ignition . If you want to do fuel fuel only, you can do that with MS2 and save some funds. I was going to do fuel only with an old ECU32, but it needed me it add a second trigger on the cam with a 5 window wheel. Doing it all at once made life easier for me.

Pulled the trigger on a MS3Pro Evo. I'll start with fuel only for now, but be able to easily add boost control and ignition down the road.

The MS3Pro EVO manual says “For fuel only installations, you will want to use a 12 volt square wave tach signal, like the one provided by most aftermarket ignition modules.”

This is where I need the most help. How does one tap into the 12v square wave tach signal? Is it simply a matter of connecting a wire to the ignition control module next to the ignition coils?

TrailAgent wrote:The MS3Pro EVO manual says “For fuel only installations, you will want to use a 12 volt square wave tach signal, like the one provided by most aftermarket ignition modules.”

This is where I need the most help. How does one tap into the 12v square wave tach signal? Is it simply a matter of connecting a wire to the ignition control module next to the ignition coils?

Yes exactly, I'm not sure on 3Bs but on a 20vt there's 2 ring terminals on the coil, 12v pulse from ECU and ground, you can just run another ring terminal from the appropriate post back to your ECU.

To clarify, could I splice the MS3Pro CKP+ Wire (which is the wire the MS3 instructions say to use for a hall sensor - see below) with either the Mac-14 ECU Hall Sensor Timing Signal (Pin #27) or RPM Sensor Signal (Pin #11)? If so, which one #27 or #11? There is also a Tachometer wire (#7) from the Mac-14 ECU that I assume goes to the tachometer and a Ignition Module Control wire (#22).

The MS3Pro EVO manuals states the following:

4.3.4 Fuel only installations
CDI ignitions send a high voltage pulsed signal, from 300 to 600 volts, to the coil. You do not want to try to get a tach signal from the coil by any means when using this sort of ignition, including external adapter boxes. Instead, use the ignition box’s tach output wire to the CKP+ instead if you are using a distributor advance mechanism to control timing and just want the MS3Pro to control fuel. Do not use the CKP- wire or the CMP+ and CMP- wires.