Jump to content
The mkiv Supra Owners Club

Rough idle and deceleration problem.


Kaan W

Recommended Posts

After going for a little drive and after some short bursts of acceleration ive noticed the car decelerating in an irregular motion. I can noticably feel this and see it on the rev gauge as if the cars running out of petrol and can see the needle dipping as its going down. It doesnt do this all the time but if im doing say 40mph then decelerate it starts doing it but I dont know why. I dont know if it could it be a faulty sensor I just havent got a clue.

 

The car is being mapped by Ryan next week so it can be sorted then I guess but its just bugging me why this is happening all of a sudden and if its safe to drive?

 

Thanks.

Edited by Kaan W (see edit history)
Link to comment
Share on other sites

  • Replies 52
  • Created
  • Last Reply

Top Posters In This Topic

Thanks :looney:

 

I guess it could be something ecu related as I think after switching off then back on it stopped doing it. It seems to be after hitting the rev limiter when shifting manually I get it and thought it could be some kind of limp mode that needs the engine switching off then on again :shrug:

Link to comment
Share on other sites

Thanks :looney:

 

I guess it could be something ecu related as I think after switching off then back on it stopped doing it. It seems to be after hitting the rev limiter when shifting manually I get it and thought it could be some kind of limp mode that needs the engine switching off then on again :shrug:

 

If your car has an issue, why are you hitting the rev-limiter?

 

Nurse it and get a clean bill of health first...

Link to comment
Share on other sites

I think you need to do some serious research before going further :)

 

Research what? :conf: I thought this was the perfect place with the amount of knowledgeable people on here that can maybe help me. Do you know what it could be?

 

If your car has an issue, why are you hitting the rev-limiter?

 

Nurse it and get a clean bill of health first...

 

I didnt think it had an issue but after the second time this has happened I know that it may well be an issue.

Link to comment
Share on other sites

Research what? :conf: I thought this was the perfect place with the amount of knowledgeable people on here that can maybe help me. Do you know what it could be?

 

 

 

I didnt think it had an issue but after the second time this has happened I know that it may well be an issue.

 

 

i think what they are saying is that you know nothing about the system that is in place in your car! and that most if not all your problems are not actual problems and is your kit just doing what its ment to do to save your engine,

 

IE, you may have been booting it alot intake temps get hot you get det ecu pulls timing , or oil preasure drop as it fins out with heat,

 

it could be many things just let Ryan see what the ecu is logged and sort it out next week mate

Link to comment
Share on other sites

Research what? :conf: I thought this was the perfect place with the amount of knowledgeable people on here that can maybe help me. Do you know what it could be?

 

I find it worrying that you obviously don't know a huge amount, yet are spending a huge amount to build a hugely fast car.

 

Buying and reading this book will help you more than you could ever imagine: http://www.google.co.uk/products/catalog?hl=en&rls=com.microsoft:en-gb:IE-Address&q=street+tuning+book&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&bvm=bv.41018144,d.ZG4&biw=1229&bih=892&wrapid=tlif135833110375310&um=1&ie=UTF-8&cid=17378937359483574409&sa=X&ei=6Hz2UP69C8iGhQeAqIGQDw&ved=0CE4Q8wIwAw

Link to comment
Share on other sites

I find it worrying that you obviously don't know a huge amount, yet are spending a huge amount to build a hugely fast car.

 

Buying and reading this book will help you more than you could ever imagine: http://www.google.co.uk/products/catalog?hl=en&rls=com.microsoft:en-gb:IE-Address&q=street+tuning+book&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&bvm=bv.41018144,d.ZG4&biw=1229&bih=892&wrapid=tlif135833110375310&um=1&ie=UTF-8&cid=17378937359483574409&sa=X&ei=6Hz2UP69C8iGhQeAqIGQDw&ved=0CE4Q8wIwAw

 

Tbh I dont know nothing about the functions of ECUs and there saftey features or how they work which is why I take the car to a knowledgable person to have the work carried out, however I do have a reasonable idea about basic mechanics and can carry out most tasks to rebuild or change an engine im just useless when it comes to the electrical side of things.

 

I just thought this forum was the perfect place for what may sound like stupid questions, but in all fairness may help for simular problems that may occur with other members in the future.

Link to comment
Share on other sites

Right so ive just been out again and its still doing it, when accelerating its fine but as soon as I let off or sit at traffic lights just ticking over its slightly reving up and down and not stable like it should be. It seems to have only just started doing this so im a bit confused.

Link to comment
Share on other sites

Right so ive just been out again and its still doing it, when accelerating its fine but as soon as I let off or sit at traffic lights just ticking over its slightly reving up and down and not stable like it should be. It seems to have only just started doing this so im a bit confused.

 

Alternator on its way out and the voltage varying causing the injector loads to change?

Link to comment
Share on other sites

Not great with electrical, but I think battery should be >12v and stable when engine running... I think it's 13.8v.

Put a multimeter across both terminals.

 

Yeah 13.8 is running voltage so I guess i'll check this out and see whats happening. Is there anything else it could be if the alternator seems to be charging fine?

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.