Jump to content
The mkiv Supra Owners Club

Back pressure?


ADD

Recommended Posts

For the last 6 months ive had a strange problem with the car when its runs over 1 bar.... it feels like a miss fire and hesitating feeling. So anyhow i thought i would put the exhaust bung in to quieten it down a little whilst on nights. Now the problem has completely gone away (added back pressure)!! Does anybody have any idea why this could be?? under 1 bar its fine but anything over and its horrible.

cheers

Link to comment
Share on other sites

could be down to the plugs, wrong temp grade or too large of a gap i had similar, but at a lower boost level.

 

over 1 bar so bpu, what plugs you got in there?

 

Im running IK24's mate thought they would be more than enough. Im due a plug change soon so can see if its running uber rich or not.

Link to comment
Share on other sites

http://www.mkivsupra.net/vbb/showthread.php?t=35931&highlight=spark+plug

 

;) for less than a tenner, id give the ngk's a shot, i have read atleast 3 occasions where the iridiums brake down after little milage, ik24's are the iridiums right?:innocent:

 

Ive ordered IK's now from Nic ( DOH) prob see how i get on with these ones and go from there. i changed the coil packs and conectors and got a bit of a result but then after a few mils the problem came back.

Still cant see how the added back pressure is stopping the problem, coz im getting to around 1.3 bar with it in and no problems at all.

Link to comment
Share on other sites

Ive ordered IK's now from Nic ( DOH) prob see how i get on with these ones and go from there. i changed the coil packs and conectors and got a bit of a result but then after a few mils the problem came back.

Still cant see how the added back pressure is stopping the problem, coz im getting to around 1.3 bar with it in and no problems at all.

 

you seem to have had exactly the same results as me, with the connectors and such, it could well be the plugs are just starting to go and the bung is bringing something within tolerance, never used the IK's personally but i know if the fuel is not good they dont like it, i am on NGK's, there cheap do the same job and dont brake the bank should it start to miss again, i had 2 sets of NGK before changing the gap, from 1.1mm down to 0.85mm and no sign of a misfire, you cant change the gap on the IK's.

Link to comment
Share on other sites

if its a deffinate under/over the 1 bar mark, maybe a dodgy FCD / BCC

 

altho at 1.3 bar id guess a different ecu altogeather:)

 

The FCD did come to my mind but once again its to much of a coincidence it goes with the bung in. my b/c is constantly playing up anyway, i cant get it to set boost. oh and with it off (which it always is) i can get 1.35 bar but with it on i get lower boost! now i didnt think they could lower the boost levels?? :rolleyes:

Thanks you for your help so far dude

Link to comment
Share on other sites

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.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.