dhdenney

iTrader: (53)

Just wondering. Someone said mine must be purging at WOT due to the brief black puff going down the strip.

HumpinSS

iTrader: (1)

I have but i think it has to meet certain PT conditions for it to purge

dhdenney

iTrader: (53)

Has it affected anything since you did so? Do you even notice? My gas tank won't explode if I do this will it?

HumpinSS

iTrader: (1)

i physically removed the evap solenoid and the only thing that happens is the car runs REALLY rich after each fill up but id back to normal about 2-3 miles down the road

GuitsBoy

iTrader: (4)

I still have my evap controls and My car is still very rich after each fillup. I get -20 LTFTs for the first few miles. Why is that?

HumpinSS

iTrader: (1)

only thing i can think of is depressurizing the gas tank

95 TA - The Beast

iTrader: (2)

Ok, I went the whole 'pull off all the evap stuff' route a few years back, and there are a few reasons why you do not want to do that...

First off it is the only way for your gas tank to vent excess pressure if the fuel tank vent valve gets 'stuck'. The vent valve is the small white valve down by the body plug-in for the harness for the fuel pump and it is to allow air into the tank, so as not to vacuum lock the fuel system, as well as venting excess pressure that builds up, but a VERY common failure mode is for it to allow air in,but no longer allow for venting of excess internal pressure. I know this because I replaced mine after I started burning out fuel pumps (I have a large fuel system, external SX pump, -10AN feed, -6AN return, and before I added the fuel cooler I was burning up pumps due to vapor lock from overheating the fuel), and when I had the evap system disconnected there was no way for excess pressure to vent, thus I was burning out pumps within a few weeks. After I replaced the vent valve the problem went away for a few months (but I did start noticing a gas smell after I parked the car, as the vent was obviously working), but then one day the smells went away and about a week later I lost another pump.

So, in the end I hooked the evap back up (with the evap hooked back up I noticed no more gas smells) and I added a large fuel cooler with fan and I have yet to burn this one out in the past 3-4 years... I have yet to buy a new vent valve...

So, the key with the evap is it is another way excess fuel vapors get released into the intake when the pcm commands it... Which can only help if the vent valve isn't operating properly...

Now, as to why your car has a burst of black smoke I do not believe can be attributed to the vent system, as it is vapors, not raw fuel... Same goes for the guy with the weird running for the first few miles after filling up...

I mean if your cars have a ton of internal tank pressure (and pressure will build-up with any fuel pump setup because of heat from the muffler and in the case of non-stock fuel pump setups that do not use the stock in-tank 'catch-can', you are recirculating hot fuel from the fuel rails back into the tank), maybe the vent valve is siezed and not working at all... and in that case I would start looking into fixing the real source of the problem, vs just removing the EVAP, as in my case it just caused the quicker demise of fuel pumps for me...

HumpinSS

iTrader: (1)

With the ls1 i think its a little different. my evap hoses are still hooked to the manifold so it is still pulling/venting the tank (in essence open all the time) via vacuum in the manifold. I just lost the control to purge at those specific PT conditions( my solenoid is gone hoses still there and hooked up to the provisions in the manifold)....

dhdenney

iTrader: (53)

Thanks for the info guys. I'll check my vent valve.