EBCS set up options
 

Hello all,
I'm trying to pull everyone's collective knowledge on an alternative way to hook up a EBCS to the stock ECU without using the Evap Solenoid connection. @DeliciousTuning said it was possible while tuning my car. Why not use the Evap Solenoid connection you ask? Well in my line of work I have seen more solidly engineered pumps be destroyed by cavitation caused by a loss of net positive suction head. It's my understanding(correct me I I'm wrong) that taking away the Evap Solenoid causes the fuel pump to draw a vacuum in the fuel tank as it's no longer vented, which cause the suction of the pump to drop to a even lower pressure possibly causing cavitation. Is this possible or am I better off going to a full electronic boost controller?

This is a very valid concern and I'm glad you are thinking about this issue rather than just accepting a solution blindly. Consider this though. There are two solenoids. One is the evaporative purge solenoid. This directly controls the amount of fuel tank vapors going into the engine. The other is the vent valve. This basically deals with pressure in the fuel tank itself.

If I understand correctly, the "Evap solenoid" connection is using the purge valve. In that case, your HC emissions will indirectly increase by not pulling evaporative charcoacl canister purge. Your tank should be ok though because it still has the vent valve operation.

That is my interpretation of the attached image and document. If I am interpreting it correctly, you can use the Evap solution with minimal risk of a long term fuel pump/fuel tank issue.

http://www.ft86club.com/forums/attac...1&d=1397160674

Wow... I said "Brown".

I thought about this before I installed mine. Then remembered people have been doing the same thing on subarus for years and never heard of any ill effects

That may be true, but when you are spending your hard earned money on a upgraded fuel pump you want to know for sure that 1) it's not gonna break and leave you stranded and 2) will deliver the rated fuel pressure and flow. Both things which can't be guaranteed if the fuel pump doesn't have enough NPSH.

@arghx7 thanks for the explanation I was unaware that there were two solenoids I need to check and make sure that's how the system works before proceeding. I'm not sure how to figure out fuel tank pressure though.

Right now I have an eBoost2 installed in my car. Its not yet running so I cant really comment but thats an option for EBCS features but don't touch the evap system.

I completely get where you are coming from but with so many cars doing this already I think we would have seen issues by now.

I deleted the evap solenoid on my ej because the barbs snapped off and I didn't want to buy another just to break it again. I'm sure I'm far from the only one who did it for that reason let alone however many did it for other reasons.

Cleaned up the bay, no more *****footing around delicate plastic barbs. Was a win win.

Tank has not cavitated, as was stated above there's a separate unit at the tank.

The tank pressure changes based on the temperature of the fuel (vaporizing effect), the fuel level, etc. It's a return-less system so that aspect isn't involved (hot fuel not coming back to the tank). I know a lot about fuel systems but I'll admit this is a highly specialized area.

Part of the reason is that it depends how strict of an evaporative emissions target it was designed for (EPA SHED/ORVR tests) and how the evaporative leak OBD monitor is designed.

I can see from that service manual that for this engine Toyota is using an active OBD monitor which relies on a pump to check for leaks. Other engines will check for leaks using a pressure sensor as the tank heats up and cools down. This is called a passive OBD monitor. I have more experience with these passive type of systems so I can't speak for exactly how the vent valve will operate for this engine.

I'm reasonably confident though that using the evap purge solenoid output for boost control shouldn't present a problem for the fuel system. I'm actually still a big skeptic of E85 for long term use though in terms of fuel system durability--I'm a lot more concerned about that than not running the purge solenoid.

That's a full electronic boost controller really, have you been able to figure out if it can be hooked up to the stock ECU to control boost? The reason I want that capability is for flex fuel.

I'll wait for a answer from Bill directly since he was the one who mentioned using another conection but failing that looks like it should be safe to use the Evap purge solenoid.

@arghx7 yea I don't think many owners of this car understand exactly what is supposed to take place for a proper E85 conversion. The entire fuel system needs to be redone and is one of the tasks on my never ending list of upgrades and modifications. Thanks for the explanation again.

I wasn't going to link it to the ECU at all. I'm trying to keep things as basic as possible to start. The eboost won't be doing much of anything other then keeping an eye out for over boost.

So you have no plans for flex fuel or just a a simple high and low boost thing? If the flex fuel thing wasn't in the cards is be looking at a full electronic boost controller as well.
I think @King Tut had a full EBC as well but idk how it was set up.

e85 isn't an option where I live. I would like to do a high/low boost setting eventually and the eboost can certainly do that.

I do think ecutek has developed to a point that makes the eboost2 unnecessary but I already own it so Im going to get some use out of it.

I did have an EBC. I didn't have it wired into the ECU at all. I could have used the failsafe features of my AEM gauge to trigger the EBC to go to wastegate pressure though.

Thanks for the responses really it comes down to what the tuner prefers and the flex fuel capability desired. Or just say screw it and go full standalone unfortunately never enough money to just go all out. Haha