Aquamist flow low after 3 months of no use.

scheides · Mar 4, 2009, 12:06 PM

So, I switched to E85 last fall, drove it for a while and all was fine. I had my alky turned off the whole time, and kept it full so i could use it for mapswitching in case i ever needed to fill up on gasoline.

I switched back to pump gas about a month ago, and the car runs perfect on my old tune, except for the Aquamist HFS-1. First pull, it flows what it should, then teeters off up top. Any pull after that, I get 4/8 bars of flow, and AFR's are 1 point higher on the wideband. I use 50/50 meth/water, 1.0mm jet. Normally I see 6 or 7 out of 8 bars on the flow meter when it is operating correctly. I checked for leaks around the on/off valve, flow sensor, and at the point of injection. I swapped out the nozzle with a .9mm jet, and got consistently only 2 bars out of 8.

I haven't ripped apart the trunk yet to see if there's anythign leaking back there, but I haven't seen any drippage or excessive loss of fluid.

I think it is temperature related, because I was on the dyno recently, and the temps in the dyno bay were ~60-70 degrees F, while normally the car is outside, it is much much colder, anywhere from -10 to +30F. While on the dyno, I got the normal amount of flow I'd expect, right around 6 or 7 bars.

I've 'solved' the power loss associated with this problem (i.e. just running w/o alky, straight pump gas) by installing a BBK

, but for some strange reason I have the urge to turn the alky back on and boost back up

Any ideas?

Boltz. · Mar 4, 2009, 12:14 PM

have you cleaned out the filter by the pump?

scheides · Mar 4, 2009, 12:20 PM

no...brilliant!

But how would this be temp related? Perhaps water freezing in there or something?

Richard L · Mar 4, 2009, 12:41 PM

Someone in Canada reported the same, when the temperture went down to -40C.

As soon as the car went into a garage overnight, it start to flow normal again. We think it has something to do with the viscosity.

Chart shows the viscosity doubles between 25 deg.C and 0 deg.C

dudical26 · Mar 4, 2009, 12:45 PM

Checking the filter is a good idea.
You already swapped out nozzles so its not a clogged nozzle.

I'm just guessing now - does water's viscosity change with temp?

dudical26 · Mar 4, 2009, 12:47 PM

Arggg... Richard you beat me to it...so it is realated to viscosity change with temp.

Any way to calculate the viscosity of water when mixed with meth 50/50?

Richard L · Mar 4, 2009, 01:14 PM

I found this chart by google.

Abner has posted a viscosity formula some time ago. I can seem to find it at the moment.

scheides · Mar 4, 2009, 05:52 PM

Hrm well it'll be extra warm here tomorrow and friday, I'll have to flip it on and see what happens! 45F woot!

scheides · Mar 11, 2009, 08:04 AM

Ok so on the days where its colder, I get 4/8 bars consistently. When its warmer than 32' F, I get 5 bars. When I was on the dyno, the bay was about 60'F, and I got 6/8 or 7/8 bars, as I would expect.

Last night I pulled the tank/pump assembly out and examined it. All looked fine, took apart the filter and it is nice and clean, and no signs of any leaks, anywhere.

I installed the kit last March, and if I think back it was probably fairly warm the whole time, maybe like 35+. Not sure what to do next.

Richard L · Mar 11, 2009, 09:42 AM

When a nozzle is spefied for oil, it flows differently for water. The viscosity may have something to do with it.

If you still have a cold days left, perhaps you can made a one-minute test with your spare nozzle onto a measuring glass. and repeat the same test on a warmer day.

If I have time I will freeze a gallon of water/methnol overnight and run some tests. I want to find out the mystery soon so that I can design some counter mearure if there is a drop in flow or just reading lower by the flow sensor.

scheides · Mar 11, 2009, 09:51 AM

IDK, there's several other aquamist kits running around MN, I haven't heard any of them report this problem. I could switch back to 100% meth I guess....

scheides · Mar 11, 2009, 10:14 AM

* and they're all running 50/50 that I know of.

scheides · Mar 17, 2009, 02:27 PM

Well sure enough, its 50'F here today and I get a solid 6 bars of flow. At least I can be happy for a while

naudlee · Mar 18, 2009, 08:54 AM

how could it evaporate/disperse with a sealed cap? I think a leak is depleting your fluids

scheides · Mar 18, 2009, 08:56 AM

Nope. The tank was 100% full the entire time, I never topped it off. I had some issues with leaks last summer and had replaced the tank and re-sealed everything.