Jellybean Posted July 26, 2012 Author Share Posted July 26, 2012 In the Diagram, I dont have a Vacuum Switching Valve between the h pipe (Map sensor & Gas filter) & Fuel regulator Plus I dont see one in your pic hmmmm; maybe USDM thing http://www.mkivsupra.net/vbb/attachment.php?attachmentid=13939&d=1112558977 Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 26, 2012 Share Posted July 26, 2012 Yeah, we don't have that. Didn't even notice it on the diagram! Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 26, 2012 Share Posted July 26, 2012 Thanks Ian , will give it a go tonight Triple check the h pipe under the manifold , but from what I remember the EVAP outlet Hose goes to the h pipe; the two hoses from the h pipe go to the VSV ; whick would mean , instead of one fo the hoses going to the check valve in your diagram it is get rerouted back to the EVAP outlet circuit That sounds like a simple way of blocking off that hose, then - just looping it back on itself. That means t'ing it into the boost controller and gauge circuit should make zero difference. Makes me suspect dodgy wiring to the MAP even more. Reason behind thinking it was a hose pop-off is, the car started overfueling after I came off boost for a slow corner back onto the main straight; as soon as I tried to put the foot back in she started trying to die on rpm & overfueling. I was under the impression a MAP sensor will not just suddenly die, maybe the heat for the engine bay's morning session got to the MAP sensor. I've never heard of a MAP sensor being the cause of a problem, so it's not high on my suspect list. But wiring can be damaged, fretted, break in some way quite easily and cause such an intermittent fault. If the MAP sensor saw atmospheric pressure, i.e. a hose popped off, the ECU would fuel for 1bar absolute. This is far too much when idling or at light throttle openings, it'd overfuel a lot and struggle to keep running. The flipside of this is, going on boost would run dangerously lean as the MAP sensor would never see the positive pressure and never fuel for the extra air. I know of one person who lost a stock motor because of the hose coming off the MAP sensor while on boost. Does any of that match your symptoms? Something else you can do to test matters is to swap the hoses whle the engine is idling normally. Do it without disturbing the wiring My bet is that it causes no problem at all But wiggling the wiring is the easiest first test still. Quote Link to comment Share on other sites More sharing options...
Jellybean Posted July 26, 2012 Author Share Posted July 26, 2012 She is working! Thanks Ian owe you a few beers! Looks like it was a loose MAP sensor connection ; what puzzles me is the car appears to work fine with the Idle air Ref hose disconnected even though the Map Sensor was loose but as soon as I connect the Idle air Ref hose the Engine light , over fueling, rough idle all kicks in. It is a bit puzzling! why the car does not over fuel with just a loose Map Connection! Why it needs the Idle ref hose connected I dont know! Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 27, 2012 Share Posted July 27, 2012 (edited) Try blowing into the end of the idle air ref hose while it's unplugged, see if it leaks If it introduces an air source it could change some things, but usually just a higher idle with sucha small hose. What made you think it was the loose connection after all? Did it alternate between working and poorly as you moved wires around? Edited July 27, 2012 by Ian C (see edit history) Quote Link to comment Share on other sites More sharing options...
Jellybean Posted July 27, 2012 Author Share Posted July 27, 2012 Try blowing into the end of the idle air ref hose while it's unplugged, see if it leaks If it introduces an air source it could change some things, but usually just a higher idle with sucha small hose. What made you think it was the loose connection after all? Did it alternate between working and poorly as you moved wires around? Hi Ian I went through the whole EVAP system, blowing through hoses etc to see if any leaks , none! I did notice on the check valve the silicon hose was rather short for my liking so I replaced all the hosing but I dont think the seal was compromised by the short hose. When I tried the Map sensor it was not fully clicked in , so I just pushed it in till it clicked on the intake connector! I reconnected the Idle air Ref hose after I replaced the check valve hoses ; and no issues; took her for a spin , she boosts fine no engine light, over fueling ; I presume with the Idle air ref hose connected the MAP sensor comes online or is more sensitive at idle because the Idle air ref hose is dependant on the MAP sensor, I presume for the Idle? Why the car was not illustrating the same symptoms regardless if the Idle air ref hose is connected or not is a bit or a puzzle; because I did drive the car with the map sensor not fully connected to the intake loom and see did seem to run fine when the Idle Air ref hose was off but not good with the Idle air ref hose connected. Maybe replacing the Check valve hoses and the hose up by the fire wall helped too but from what I could find from blowing into the pipes , they did retain pressure (no leaks) As a treat Ian , I made this Video for you http://youtu.be/qyYvFiHFeK8 Quote Link to comment Share on other sites More sharing options...
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