Positioning Of Inlet Air Temp Sensor?

[B1ack_Mi16 67]

I've been done a little mapping on the 2.3 now, and it idles pretty good, but there is a problem.

After idling for a while the AFR's suddenly rises and idle drops to 700rpm, barely running. Blipping the throttle at this stage will make it die.

 

I've mounted the air temp sensor on the filter backplate so I'm suspecting that's where the problem lies.

 

It idles so nice at 80 degrees coolant and 15-25 deg inlet air temp readings, but when inlet temp rises to like 30degrees C and coolant was up at 90C it started behaving bad.

 

Where have you other guys running TB's placed the air temp sensor?

[Robsbc 0 1 Cars]

I've been done a little mapping on the 2.3 now, and it idles pretty good, but there is a problem.

After idling for a while the AFR's suddenly rises and idle drops to 700rpm, barely running. Blipping the throttle at this stage will make it die.

 

I've mounted the air temp sensor on the filter backplate so I'm suspecting that's where the problem lies.

 

It idles so nice at 80 degrees coolant and 15-25 deg inlet air temp readings, but when inlet temp rises to like 30degrees C and coolant was up at 90C it started behaving bad.

 

Where have you other guys running TB's placed the air temp sensor?

 

Unless your gonna run an enclosed airbox with the sensor mounted in there then your gonna have the issue you talk about....If it idles ok @ 15-25deg then you might need to look at your air temp corrections at 80 degrees plus....

 

My own car on tb's the air temp is mounted in the filter plate also and I don't have issues with the car idling at 80 degrees...

 

Like said before in another post if you want the perfect idle like a production car fit an idle air control valve.

[B1ack_Mi16 67]

Unless your gonna run an enclosed airbox with the sensor mounted in there then your gonna have the issue you talk about....If it idles ok @ 15-25deg then you might need to look at your air temp corrections at 80 degrees plus....

 

My own car on tb's the air temp is mounted in the filter plate also and I don't have issues with the car idling at 80 degrees...

 

Like said before in another post if you want the perfect idle like a production car fit an idle air control valve.

 

I understand that with the idle control valve.

But this issue is pretty strange and has nothing to do with my earlier issues about getting it idle from cold.

 

The air temp corrections is +4% at 10 deg airtemp, and -4% at 30 deg airtemp, same as the Mi16 maps supplied on the disc with the emerald.

 

Anyway the air might have been 10 degreees and sensor told ecu it was 30 deg airtemp.

 

That's 8% lesser fuel, but with 14:1 AFR to start with a change of 8% in fuelling will only take the aft to approx 15:1, so it might be something else too, not that I can think of what that could be.

 

Hopefully the temp readings will be more correct once I get this thing rolling anyway.

 

Btw .could you possibly send me your Map file? Email: kristian@wdesign.no

[TT205 42]

On mine we have lowered the radiator and then fixed a sheet of plastic horizontally on top ending under the tb's (it's horizontal in other words. Very little heat around the tb's, whatever the engine temperature. My sensor just dangles next to 1st and 2nd tb

[B1ack_Mi16 67]

On mine we have lowered the radiator and then fixed a sheet of plastic horizontally on top ending under the tb's (it's horizontal in other words. Very little heat around the tb's, whatever the engine temperature. My sensor just dangles next to 1st and 2nd tb

 

Ok I see. The problem is just there after I've driven, parked the car for some while so it's heat-soaked.

Then air-temp goes to like 50 deg C when I start it, inlet draws most of the air from the front anyway, and little air-flow around the back-plate of the filter means it takes some minutes for the temp to drop to normal levels.

 

I think I'll move it to somewhere in front of the inlet.

[stevec205gti 0]

Ok I see. The problem is just there after I've driven, parked the car for some while so it's heat-soaked.

Then air-temp goes to like 50 deg C when I start it, inlet draws most of the air from the front anyway, and little air-flow around the back-plate of the filter means it takes some minutes for the temp to drop to normal levels.

 

I think I'll move it to somewhere in front of the inlet.

 

I was about to say - sounds a lot like heat soak. The problem is not the air itself being hot, just the sensor giving you the wrong fuelling for the actual air you're sucking in. Can you make a "plastic" holder for the sensor so it's not screwed into metal? This could simply be a threaded sleeve - just somthing to insulate it. I'd have thought that even if you move it, there's still the risk of heat soak if it's still screwed into metal.

[mos 1]

black mi16

 

how have you got to the bottom of this yet?

[B1ack_Mi16 67]

black mi16

 

how have you got to the bottom of this yet?

 

No, sorry, as I wrote in the PM I've not really had any time to try to change this yet.

But I'm pretty sure it's just too little airflow around the back-plate.