GT-ER

iTrader: (4)

I bought a cooling mist system and installed it. It has a pressure switch that is activating the system at about 6psi and a light that tells me if there is pressure in the system when it activates to ensure it's working. I first had a 500cc nozzle installed and the car would run find except for when I let off and got on it again, then it would misfire so bad that the car would literally feel like it would shut off for about 1-2 seconds and then restart. If I shut the car off without going WOT a few times with the system off it would be a nightmare to get it back on again afterwards.

I figured my nozzle was simply too big and it was dumping too much water/meth so I put a smaller nozzle in ( 380cc ). It still does it. It REALLY bad.

I leaned my car out to make up for the difference the meth makes...right now it's running about 12.0-12.2 on the meth so it's obviously not to rich. What I do notice is that when I let off, the meth light stays on for about 2-3 seconds and then turns off. I'm guessing it's staying on while the pressure in the lines gets alleviated and turns the switch off. But this would also mean that the system will still inject for 2-3 seconds AFTER I let off ( which is probably why I'm getting the problems AFTER my first flawless run ).


SO... what do I do? Run an even smaller nozzle? Anything I CAN do? Has ANYONE had this problem?

FWIW, My nozzle is placed after the maf, before the TB.

streetzlegend

iTrader: (2)

From what your saying, it sounds like its still spraying after you let off like you said. Few options I can think of; you can increase the boost inwchich it activates, instead of 6 maybe 8, that way when you let off it turns off sooner, or you can also find a solenoid you can put right at the nozzle, so when you let off the solenoid closes. Where does the pressure switch get the vacuum/boost reference from? Try to get it from a good size vac line so there is a faster reaction when you let off. 380cc is a pretty good size, i wouldnt go to 500 if it was mine. I got 7gph on my setup and I think its more than enough.

From what I have always read, the rule of thumb for picking a nozzle size is, if when you spray it, it drops your afr more than 1 point, then its too much.

GT-ER

iTrader: (4)

My A/F only goes down about .5. The problem isn't the pressure switch because it shuts off instantly when I let off....the residual pressure in the system is what is keeping the nozzle "ON" until the pressure goes down low enough to simply stop.

You idea of the solenoid is pretty good though...does everyone have solenoids though?

streetzlegend

iTrader: (2)

I think i know the problem, did your kit come with a check valve? Some kits come with solenoids, most dont. However all should come with check valves, they are a must. You wanna put the check valve as close to the nozzle as possible, so when the pump turns off the checkvalve closes right away (since they have certain cracking pressure to open)

GT-ER

iTrader: (4)

Mine has a check valve placed about 12 inches from the nozzle.

djamps

iTrader: (1)

I would suggest installing a solenoid. A check valve will prevent back-flow but I don't see how it's going to stop the pressure from the pump spooling down --I think this is the 2-3 seconds of extra spray...you want that spray to stop the split second you let off.

GT-ER

iTrader: (4)

That's exactly what I'm thinking...but it makes me wonder if anyone else running just the checkvalve is running into this problem?

350z 6spd

iTrader: (9)

I fought this problem FOREVER in my car. I have 2 175ml/min nozzles and everytime I would have the exact same problem as you are describing. My pump activation light goes off instantly but after the many tests I've conducted, I've noticed there is definitely a little residual pressure as you are saying.

My car has a t-fitting just behind the plenum and I have a check valve right before the t-fitting. Now, before the t-fitting was sitting right near the top of the plenum (between the plenum and firewall). I thought maybe the check valve would fix the problem like you guys are saying but it didn't. I figured out that the extra fluid in the lines after the check valve (the 2 lines going from the tee to the nozzle) would slowly dribble into the piping after the residual pressure was gone. This caused large water/meth droplets/puddles to be sitting in the intake. So the problem, as I have found it, was not the residual pressure as that is somewhat atomized, but the residual little droplets/puddles caused by gravity.

I fixed it by lowering the tee fitting so it could rest near the bottom of the plenum (below my intake piping) instead of near the top. I also moved my nozzles from the side of my intake piping to directly on the underside of the piping. They sit vertical just in front of the TB's. I then made sure that the line went downwards all the way from the nozzle fitting to the tee fitting with absolutely no upwards angle to promote flow to the nozzle without pressure.

I was hoping someone could possibly benefit from all the crap I went through trying to figure out what was wrong with my system lol. Hope it helps.

streetzlegend

iTrader: (2)

This is weird, because I have had mine for about 3 years or more and never had this issue. The checkvalve is not there to prevent backflow (since there is no way that can happen anyway), its there to prevent fluid from leaving the line when pump is off, it has a cracking pressure, so only allows flow when the cracking pressure is reached. Instead of a solenoid you can find a higher pressure check valve such as this one: http://www.alcohol-injection.com/check-valves-64.html, has 16psi cracking pressure.

GT-ER

iTrader: (4)

I have the nozzle pointed slightly downward on the upper/side portion of the pipe...what you say makes sense. I'll have to move the nozzle below the pipe and point it upward to see if that helps.

I might try out another checkvalve as well...I dunno.

streetzlegend

iTrader: (2)

I would assume its not the position of the nozzle, but the position of the hose, if the hose comes from below then it shoudlnt be an issue, if it comes over the top and pointing down then yea. The check valve should take care of it, try putting it right on the nozzle, and see if its a pressure one not just one way.

350z 6spd

iTrader: (9)

Streetzlegend, I thought so as well. So, after I fixed the issue and positioned them below the piping, I got curious and tried to move them back to the side of the pipe with all of the hose facing down and the problem came back.

GT-ER

iTrader: (4)

Okay, I checked the tubing and there was a spot that was indeed higher than the nozzle and it was post checkvalve as well. I repositioned it and placed all the tubing below the nozzle....tomorrow I'll use the system to see how it goes.

maXmood

iTrader: (16)

keep us posted.. and pics are a plus

str8dum1

iTrader: (11)

FWIW, i was using a 600cc nozzle, so injection wise you should be fine after you get the pooling sorted out.

GT-ER

iTrader: (4)

I tried it again today and the same thing happened. First run is super smooth and pulls hard. 2nd run and up it starts to buck heavily and will barely accererate. I turn the system off and do a few WOT runs and it cleans out and everything goes back to normal.

str8dum1

iTrader: (11)

post a message on the cooling mist forum. They have some of the best tech support. If you can call, even better. The guy that answers really knows his stuff.

GT-ER

iTrader: (4)

I'll do that, let's see what they say and I'll post it here.

str8dum1

iTrader: (11)

they are super active on the srt4 forums as well if you dont get a good answer. I always read/post over there when I have a meth question

http://www.srtforums.com/forums/f189/

350z 6spd

iTrader: (9)

Did you try moving the nozzle so the outlet is facing straight up from the bottom of the intake piping? It took me months to finally figure this out so that it wouldn't start pooling. It's the only way mine will work.