Jump to content
The mkiv Supra Owners Club

Unusual problem with Na-t


scott87

Recommended Posts

Ok so im sure a lot know im taking the aem out of my car and fitting a different unit as i just couldnt get on with the aem and get it to function correctly in my car. Anyway the car is na-t in essence except for the having a mapped ecu part. The car has been running fine and obviously has been kept off boost for times when i need to use the car or i have moved it to various places to do work on it. Its been running absolutely fine then the day before attempting to map the aem the car started to be a bit lumpy and hesitant, mainly under load. A quick error check and this brought back a map sensor error. Anyway checked all the wiring and put the bridge back in as the car has been running on this not the ecu, so stock wiring. Started the car and the error had gone and the car ran fine.

 

So finished up my cuppa started the car and took a leisurely drive home. About 3 miles into my journey the lumpyness returned and gradually got worse. So i windered whether the cable had perhaps loostened itself or a dodgy connection. Today i removed the section of wiring to the map sensor that had been fitted as part of the aem loom, so the map wiring is back to stock with a little bit of extra wiring there to make up for what was removed. Again started the car and the car was much better at idle. Took it for a nip round the block to get tax and the lumpiness is still there. It is not as bad as before and if you 'push' through it with gentle acceleration staying off boost, you can get through the lumpiness. But again this is exactly the same feeling the car had when the map sensor was throwing a code.

 

So my real question is am i likely to have knackered the map sensor, or is this likely to just be the fueling jibbing out a bit with the alterations. The new ecu and mapping is occurring at the end of the month but it just seems an odd fault to develop when off boost the car is exactly as it was before the turbo was fitted. Granted it isnt ideal using the car, not to mention how slowly i have to go to stay off boost, but ireally just want some useful information on the fault rather than just stop using it and wait to map. Because if the fault is something that will hinder mapping i want to fix it first obviously. Thanks in advance, and probably thanks to David who will answer this first :p

Link to comment
Share on other sites

So the fic us out and running completely stock ecu?

Could it be something daft like moisture in the spark plug wells?

If you think it's the fuel trims pull the negative terminal on the bag for five minutes then go for a drive, after reattaching it obviously and see if that cures it or if it comes back after 15 minutes,

What ecu you going for next?

Link to comment
Share on other sites

So the fic us out and running completely stock ecu?

Could it be something daft like moisture in the spark plug wells?

If you think it's the fuel trims pull the negative terminal on the bag for five minutes then go for a drive, after reattaching it obviously and see if that cures it or if it comes back after 15 minutes,

What ecu you going for next?

 

Yer thats right. The whole time the car has been running on the stock ecu. The aem comes with a bridge connector so that the stock wiring can be used so the aem could be removed easily. As the aem couldnt be mapped, i have been running the car using this bridge.

 

I have checked for moisture and that is not present, my new mod to the bonnet has stopped this. It definitely feels like a map sensor error. Im wondering whether the ecu would need resetting now that i have returned the wiring to stock. Would the ecu need this?

 

Im going for a det3 with launch control :D

Link to comment
Share on other sites

the pipe next to it :)

 

they are strange things. ive done 5 na-ts 3 I could t into the map line fine . 2 of them had your symptoms exactly unless I left the map line alone

 

The pipe next to it goes to the charcoal canister?

 

Thanks very much for your help lets hope it cures it :)

Link to comment
Share on other sites

no the other side that goes into the manifold from the thin pipe that comes from beneath the manifold

 

You sir are my favourite human being!!!!

 

I changed the t section to the pipe next to the map sensor one and touch wood the problem has completely gone away! :D Its so odd that the car was fine for a fair few miles then this problem started....

 

Im hoping that is the end of that. And for such a simple fix too! Its back to driving like an na off boost and means i can pootle to work off boost on days like today when its chucking it down! Thanks very much...

Link to comment
Share on other sites

You sir are my favourite human being!!!!

 

I changed the t section to the pipe next to the map sensor one and touch wood the problem has completely gone away! :D Its so odd that the car was fine for a fair few miles then this problem started....

 

Im hoping that is the end of that. And for such a simple fix too! Its back to driving like an na off boost and means i can pootle to work off boost on days like today when its chucking it down! Thanks very much...

 

 

takes bow ;)

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.