Rough start after WI installation...

[Chuck-S4]

Small problem with motor start / car ignition.

An Aquamist 1s kit was installed on an Audi S4 (2.7 Twin-Turbo); system is working great under WOT, no doubt... Max Fuel flow is approx 2100CC/min and we use twin 0.5mm jets (total of 400CC/min), (ratio slightly below 20%), running 35% Methanol / 65% H2O (windshield washer fluid). The Aquamist system is set to 8PSI.

We went WOT for a few test runs, everything was fine... We let the car sit (immediately after WOT I must confess...) for 60 minutes. We went back, motor still mild-hot, and started the car. Tthere was the problem; it did hesitate approximately 2 seconds before the motor actually started (like a cold start on C-16 - Xylene / Fuel mixture). After that, the motor runned ok.

Is it a normal? If not, is it mixture related (methanol causing rough starts)? or is it because I have excessive flow (twin 0.5mm)?

[Richard L]

Interesting - need to know more.

Where are the water jet installed? Without a priming pumop, the 1s system cannot inject more than 330cc/min.

[Chuck-S4]

Richard,

Well, if the pump is maxed out at 330CC/min without a priming pump, it's even better for me since the ratio would be around 15%. right on the spot.

Somebody from Audiworld have posted a nice theory. A similar problem occured to him when he first installed the Aquamist kit. The actual source of the problem was that some big carbon deposits were being flushed out of the motor, results of the methanol/H20 injection, cleaning the cylinders(and fooling the plugs).

I'll keep you all posted on this theory.

[Richard L]

Richard,

Somebody from Audiworld have posted a nice theory. A similar problem occured to him when he first installed the Aquamist kit. The actual source of the problem was that some big carbon deposits were being flushed out of the motor, results of the methanol/H20 injection, cleaning the cylinders(and fooling the plugs).

I'll keep you all posted on this theory.

Not sure which was first, flushing out the carbon deposites and (fouling) the plugs second ?

Would it be quicker to eximine the plugs and see what actually happened.
Please keep me posted - Still not sure what was happening.

Where did your place the jets?

[Chuck-S4]

Where did your place the jets?

The jets are located on each side after the ICs, probably 12 to 15 inches before the throttle body.

I have to change my plugs next week so timing is excellent. I'll look at the plugs and also inside the cylinders to see if some deposits are still there...

The car did it again yesterday. What we found out is that it does happen when we shut the motor off almost immediately after going WOT... If we let the car sit running idle for 20-30 seconds and then shut it off, it starts OK.

[janis]

Where did your place the jets?

The car did it again yesterday. What we found out is that it does happen when we shut the motor off almost immediately after going WOT... If we let the car sit running idle for 20-30 seconds and then shut it off, it starts OK.

Isn't that scary? Shouldn't you let things cool down first anyway? The oil inside one of your turbo's could burn up because of the heated turbo resulting in clogged oil lines.

Or do you have a turbo-timer?

[Richard L]

Could the water droplet affecting the some sensors such as the hotwire airflow sensor?

If the water wet it , it will think the air is very cold and dumping a great deal of fuel into your engine so it is difficult to start until the film of water has evaporated?

[Chuck-S4]

Found the problem... at last!

Totally **unrelated** to the Aquamist Kit ; unfortunately, the first time the problem occured was *immediately* after the ERL Aquamist pump. When it does happen right after an installation(the problem), well you tend to point at it and think it's the source of the problem.

Problem was the O2 Sensor wires that were sending intermittent signals ; wires were not installed correctly back last spring and were too close to the exhaust line, making them melt slowly but surely... Proper relocation et insulation solved the problem.

With correct O2 signal, everything is fine... Pumpin' good!