adi Posted March 12, 2003 Share Posted March 12, 2003 hi.. this is a 1JZ question so prob not apllicable to the mkiv's but i thought id ask anyway seeing as its a general technical question... Ive just replaced the part below for a bit which allows me to plumb in my boost gauge into the map pressure line.. The old bit (which went between the MAP sensor pipe and the inlet manifold)) is a funny shape, and it isnt a straight through hole from one side to the other.. it appears to follow a route inside the part, perhaps going through some filter or something to straighten/restrict the air flow... now, my new bit obviously doesnt do this (air in - air out)and i'm wondering if it will cause any probs to the MAP sensor. I cant fit the adapter *and* the original air bit on as there isnt enough room.. Anyone know if the stock piece is designed to tamper with the air flow in some way? Like i say, i dont think you have this piece on a mkiv but maybe someone with a bit of tech know how would know the answer? Cheers adi Quote Link to comment Share on other sites More sharing options...
adi Posted March 12, 2003 Author Share Posted March 12, 2003 oh.. and heres my new bit... Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted March 12, 2003 Share Posted March 12, 2003 Can't help with your question. But why didn't you just T into the rubber hose shown on the left of your second picture ? That's what most of us do ? Quote Link to comment Share on other sites More sharing options...
adi Posted March 12, 2003 Author Share Posted March 12, 2003 I did... with a plastic T piece.. but the hose that feeds the boost gauge is 4mm o/d nylon hosing... and it doesnt fit onto the T piece. I bodged it on using a bit of tubing and some glue but it blew off at full boost !! Twice !! After considering its not worth the risk of making me run lean so ive decided to do it this way. Quote Link to comment Share on other sites More sharing options...
adi Posted March 12, 2003 Author Share Posted March 12, 2003 you can see it here in the pic.. is that the type of hose that feeds most of your gauges? If so how did you plumb it in to the vacuum pipe? Quote Link to comment Share on other sites More sharing options...
adi Posted March 12, 2003 Author Share Posted March 12, 2003 DOH !! just realised.. i could have used a different adaptor at the back of the boost gauge which would have allowed me to use vacuum pipe ! Oh well, i suppose the nylon pipe is a bit more sturdy for routing through the firewall i suppose. Quote Link to comment Share on other sites More sharing options...
Ian C Posted March 12, 2003 Share Posted March 12, 2003 Looks like a one-way check valve to me. What came off that bit when it was installed? Edit - from what I can gather re-reading the thread, this bit taps into the intake manifold, and has a vacuum pipe going to the MAP sensor and nothing else, right? Seems to me that if it's a check valve, and it looks like one, the MAP sensor doesn't like being exposed to vacuum perhaps? -Ian Quote Link to comment Share on other sites More sharing options...
adi Posted March 12, 2003 Author Share Posted March 12, 2003 Its two way though Ian, i can blow through both sides so it cant be that.. unless its broken , which i suppose is a possibility. perhaps its a smoother .. possibly to prevent boost spikes being fed to the sensor? I have no idea really.. just guessing. It could also house some kind of filter to prevent the sensor from getting clogged with any oil from the manifold.. who knows. Im going to run the car tonight with just the straight through new bit on and see if it does anything dodgy. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 12, 2003 Share Posted March 12, 2003 The device is a pulsation damper to smooth out rapidly pulsing waves which could upset the ECU metering. It realy should be there between plenum and MAP sensor. I'd re plumb the rest of it to allow it to be refitted. Quote Link to comment Share on other sites More sharing options...
adi Posted March 12, 2003 Author Share Posted March 12, 2003 ah right cheers Chris.. No prob to replumb it.. i'll just swap the two connections over.. i presume it wont make a difference to the pressure sent up it if its right angled off by putting it at the top connection? Logic says no but i gotta ask, dont want to be running lean now do we.. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 12, 2003 Share Posted March 12, 2003 I have been TOLD it's a damper, but usually these just have a pin hole sort of size restriction in them. My PERSONAL feeling is it's an anti back fire valve, to protect the (expensive...) MAP sensor from violent pressures in the case of a manifold backfire, but I have no proof. Either way I feel it is there for a very good reason! Quote Link to comment Share on other sites More sharing options...
adi Posted March 12, 2003 Author Share Posted March 12, 2003 hmmm.. when i blow through it there is a restriction of sorts.. id go with the smoothing theory myself.. but either way i guess i gotta refit it... i dont think it'll be too much of a pain to swap the position to the top (the only place it'll fit) so i may as well put it on. Better safe than sorry i guess.. cheers adi Just thought, i'll look on the EPC and see what its called ! Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted March 12, 2003 Share Posted March 12, 2003 That's a good idea Adi. The MKIV one is described as 'Filter, Gas' Quote Link to comment Share on other sites More sharing options...
adi Posted March 12, 2003 Author Share Posted March 12, 2003 yep.. same for me when i checked! Could mean anything really ! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 13, 2003 Share Posted March 13, 2003 Normally it's essential to have the MAP sensor higher than the intake manifold to stop any petrol puddled in the intake running into the MAP sensor. Maybe it is some sort of filter to stop fuel getting as far as the sensor? Quote Link to comment Share on other sites More sharing options...
adi Posted March 13, 2003 Author Share Posted March 13, 2003 well, the nylon pipe feeding the gauge is clear and wont be attached to the filter, so i guess if it gets full of crap over the next few weeks we can assume it was for that purpose. Quote Link to comment Share on other sites More sharing options...
adi Posted March 13, 2003 Author Share Posted March 13, 2003 Hmmm.. i've been advised on anothe forum not to tap into the MAP pressure line (just to be on the safe side) so im considering taking it off another line. Are *all* the vacuum hoses that come off the inlet manifold related to pressure? Is there any one in particular i should go for? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 13, 2003 Share Posted March 13, 2003 Any tappings direct into the plenum will see both vac and pressure, or make a new one if you prefer. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 13, 2003 Share Posted March 13, 2003 Adi, my Autronic has a built in 4 bar MAP sensor. This *must* have a dedicated line. There must be loads of other places to tee in, if not drill & tap the plenum. Quote Link to comment Share on other sites More sharing options...
adi Posted March 13, 2003 Author Share Posted March 13, 2003 Drilling and tapping is fine but i dont fancy removing the thing to do it.. so i might just tee into a piece. There are some vacuum size pipes and some a little bit thicker.. for now im going into the vacuum pipe but i can get a better connection on the thicker one.. i'll post a pic later just in case it isnt a pressure/vacuum pipe. Cheers for the help !! Oh, and apparently yes, its a filter. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.