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New AFM or something more sinister?

Skaith4224
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Skaith4224 Apprentice

Skaith4224

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Hey all, 

R33 gtst spec 2 / Rb25 DET Manual

Been having issues for a while where the engine randomly turns off. Could be idle, cruising, boosting or changing gear. More recently I've had issues with big boost where she suddenly shuts off fuel like it's over spooling. Running an apexi Fc so shouldnt be boost cutout, also have a greddy boost controller and psi looks normal. 

 

Any who, I've noticed that on the "stalls" the AFM shows a decimal down. When the engine is off, I get about 280mv but after the stall it'll show 28mv. It does move so not jammed or frozen. Shows on hand controller. 

Most of the time, to get going again, I have to turn the ignition completely off then back on to reset the ECU then the reading is fine again.

 

Does this sound more AFM sensor/loom or could it be an Ecu issue?

 

Thanks in advanced. 

Alan. 

Edited by Skaith4224
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joshuaho96 Veteran

joshuaho96

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On 8/22/2023 at 10:26 AM, Skaith4224 said:

Hey all, 

R33 gtst spec 2 / Rb25 DET Manual

Been having issues for a while where the engine randomly turns off. Could be idle, cruising, boosting or changing gear. More recently I've had issues with big boost where she suddenly shuts off fuel like it's over spooling. Running an apexi Fc so shouldnt be boost cutout, also have a greddy boost controller and psi looks normal. 

 

Any who, I've noticed that on the "stalls" the AFM shows a decimal down. When the engine is off, I get about 280mv but after the stall it'll show 28mv. It does move so not jammed or frozen. Shows on hand controller. 

Most of the time, to get going again, I have to turn the ignition completely off then back on to reset the ECU then the reading is fine again.

 

Does this sound more AFM sensor/loom or could it be an Ecu issue?

 

Thanks in advanced. 

Alan. 

You can try tapping the MAF or tugging on the plug while the car is stopped and see if it reproduces. Not unusual for MAFs to have failed solder joints when old.

Skaith4224 Apprentice

Skaith4224

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On 24/08/2023 at 4:29 AM, joshuaho96 said:

You can try tapping the MAF or tugging on the plug while the car is stopped and see if it reproduces. Not unusual for MAFs to have failed solder joints when old.

Thanks for the response, Was a little thrown off as the MAF voltage wouldn't go back to normal until I reset the ECU.

Was reluctant to start poking at the solder points if it wasn't the issue.

However, was driving Friday and the car completely died, no amount of ECU resets would get the voltage back so I got out and gave the MAF a slap, everything was then fine again.

So, Saturday, chopped the cap off and re-heated all the solder points. So far, I've been driving it for 3 days of varying lengths and so far so good!

The smell of petrol has gone, No hesitation under high boost and no cutouts!

 

Will keep testing and let ya'll know if any issues to occur.

 

Thanks,

Alan.

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