Think I\'ve got a boost leak?

[B.Martin]

So I start my car up and It won\'t idle, is sitting at 1.5k rpm. I\'ve checked all pipes, other than my DIY blanked hose it could only be 1 other hose again that I\'ve DIY\'d.  

This is the first one it could be, but I\'ve ordered a new hose blanking thing for it.



The other is this one, I suppose I\'ll need a custom one for this as the oem one didn\'t fit the BOV. So we DIY\'d it with 2 hoses as you can see!



I\'ll just have to take it all apart and get the right size and measurements and re do it all. I don\'t suppose it\'s anything to do with the coolant system and the only thing it could be caused by is me messing around with the BOV!

Is there anything else it could be?

[Prof]

can\'t really make it out too clearly in the pics - I\'m guessing they are night time shots.

[B.Martin]

Yeah they are, try and get better ones tomorrow.

[m1tch]

Where the Jubaliee clip on the pipe under the BAC? Did you not use the OEM one that came off the OEM pipe?

[papercutout]

How long is it sitting at 1500rpm? Mine idles at 1500rpm till it has warmed up, and I thought it was the normal warm up proceedure


Just want to eliminate that option!

[m1tch]

Might be an air leak, mine idled slightly higher, than I sorted out the TINY split in 1 of the intercooler hoses, now it idles correctly

Ben - does your rev up to 4k RPM when you start the car?

[papercutout]

Mine doesn\'t rev up to 4K, it almost dies, then sits at 1500rpm. How about the other Ben? (when warm, mine idles about 700rpm)

[B.Martin]

It goes upto about 3k usually, then drops down to about 500rpm. Mitch the pipe you can see in second pic which is 2 pipes made into one, were put there as the oem one wouldn\'t fit. I think it\'s got to be something to so with the BOV as it was fine before.

[B.Martin]

Okay, so i\'ve been out this morning before work and taken apart the pipe i think that could be the problem. I\'ve also taken some more pictures that i should help support my theory, at least i hope so anyway! First picture is my DIY plumbed pipe, which as i say i have a blaking peice ordered for so i can\'t do anything else to this untill it comes. You can see it here with silver ducktape on and a stock hose clamp.



Then here you will find the pipe i think is causing the problem, we had to fit 1 pipe into another to get it to fit as i think there is a bend in the oem pipe and obviously with the BOV fitted it needs to be more or less straigt, problem is it looks like the BOV pipe connection is bigger than the one on the engine. The second of the following pictures (with said pipe removed) shows the difference in outlet size.



Then with pipe removed it looks like this:



(sorry for the sun glare, kinda unavoidable) Ignore the top hose, i took that off just to get to the BOV easier. You can see though that the connection for the pipe on the BOV is a slightly different size, i will have to measure them up this afternoon to make sure i get the right size to plug this gap. Its all very odd because after i fitted the BOV everything was fine, took it for a drive etc and all seemed fine.

Any further suggestions greatly appreaciated.

[Prof]

The pipe that has the BOV attached - nornmally that has 2 smaller outlets - one goes to the BAC valve on the side of the engine through a \'s\' or \'z\' shaped hose, and the other one goes to the recirc valve.  It\'s that connection that\'s normally used to fit a BOV, but I suspect you have a downpipe that has the BOV mounted to it, which means you\'ll only have the 1 connection.
 
It should allow orientation so that the stock hose can be used for the BAC, as this does need to be airtight or you\'ll get unmetered air and bad idle.  Try rotating the BOV and Turbo to intercooler pipe until that end comes out slightly towards the wing.
 
As for the bit that\'s taped over - is that out of the back of the 90 degree bend just after the airfilter / air flow meter ?

[B.Martin]

The pipe that has the BOV attached - nornmally that has 2 smaller outlets - one goes to the BAC valve on the side of the engine through a \'s\' or \'z\' shaped hose, and the other one goes to the recirc valve.  It\'s that connection that\'s normally used to fit a BOV, but I suspect you have a downpipe that has the BOV mounted to it, which means you\'ll only have the 1 connection.
 
It should allow orientation so that the stock hose can be used for the BAC, as this does need to be airtight or you\'ll get unmetered air and bad idle.  Try rotating the BOV and Turbo to intercooler pipe until that end comes out slightly towards the wing.
 
As for the bit that\'s taped over - is that out of the back of the 90 degree bend just after the airfilter / air flow meter ?

I can\'t turn the BOV because its quite big there is no space to move it, as far as having a downpipe with the BOV fitted to it - i have no idea. Neither did Si. The stock hose we just couldn\'t get to fit as it had a bend in it and was a fair bit longer than we needed.

And the taped over bit i think is where you mean, i will add a few more pics at the bottom to confirm as i don\'t know the names of anything or what it does to be honest. I\'m a massive n00b to this engine :Giggle

In this pic you can see the taped over part just under the BOV trumpet.



And this is a closer look at it.



Thanks for help Prof, are you thinking that its just an air leak as well?

[Prof]

It\'s most likely an air leak.  When you see the size of the hole in the throttle body and BAC valve that\'s used for idle air flow - you\'ll see why even the smallest of hoses off can cause an issue.
 
Normally a vac leak post throttle will kill the idle as too much air is getting in.
 
Revving to about 1500 when cold is normal (upto 4000 rpm for 30-40 secs on cold if you\'ve got that stupid warm up solenoid still on the car and you don\'t start it with the car in 1st and clutch down (this kills the AWS warmup nonsense).

[B.Martin]

Right i didn\'t understand the last bit to well, probably becuase i\'m a bit dense! I will try and sort a pipe out that will bridge that gap and when i get the hose blanking cap i\'ll fit that too. The biggest pain in the ass is that i think the 2 connections are different sizes so i\'ll probably need a reducer peice as well as some pipe.

As for starting the car up, i usually start in neutral with clutch pressed in. Am i doing something wrong? The car usually revs upto 3-4k for a few secs then drops down to the usual idling point at around 500rpm, as you say i was always under the impression this was normal.

I\'ll try to sort this out asap but finding hoses and stuff over here is a real ball ache and ideally i\'d like to get purple samco stuff but i might just be being a bit picky as no one seems to stock these things.

[Prof]

The FC has a couple of extra solenoid valve\'s on it that are designed to push a lot fo air into the system when the car first starts.  The purpose of this is to rapidly warm up the cat - but a lot of peeps don\'t really like to rev the engines from cold like this, so Mazda have put some programming in the ECU that \'defeats\' this mental warmup.
 
NOTE - the warmup only happens when the car is started cold - not when warm started.  It revs to about 3-4K then drops back down to the normal cold idle of about 1500-2000 (does vary a bit from car to car).
 
To defeat this higher revving warmup, place the car in gear (1st) and keep the clutch down (don\'t want to go through a wall or shop window - lol) and start the car - it will only rev to the normal cold idle.
 
The system is called Accelerated Warmup - and it\'s a stupid idea !

[B.Martin]

Right okay, well even wen the car warmed up it didn\'t drop below 1.5k. I guess it\'s best to replace the hose then hope it goes back to normal.