very hot exhaust

[driftin jo]

Have you tried disconnecting the TPS connector plug ? If not try that and see if it still the same.

[miljan]

Have you tried disconnecting the TPS connector plug ? If not try that and see if it still the same.

I tried this but it just happens.

I mounted innovate wide band oxygen sensor and it shows about 12.6 air fuel ratio.
I check errors on the ecu and throw error 2121. It is Idle switch problem.

I dont know what can be it?

[prj]

1. Pressurize intake, check for boost leaks.
2. Measure fuel pressure, make sure it is OK.
3. Renew G70 (MAF).
4. Put all injectors onto a stand and check spray pattern, possibly one or more leaking.

12.6 AFR shows that the MAF is reading way too high for some reason or one or more injectors are leaking.

[A80Avant]

it makes you think though that if the afr is 12.6 and the EGTs still very high, that there might be a timing issue there as well? 12.6 is very rich, and i would expect it would reduce the EGTs a fair bit!

[diesel des]

Yea double check exhaust cam timing.

[prj]

it makes you think though that if the afr is 12.6 and the EGTs still very high, that there might be a timing issue there as well? 12.6 is very rich, and i would expect it would reduce the EGTs a fair bit!

Rich mixture does not decrease EGT's. On the contrary.
Though here the mixture is not causing this, it is timing that is completely wrong.
Whether it is retarded by ECU due to a high reading on the MAF or due to wrong cam/belt timing remains to be seen.

Anyway, my bet is on a mechanical problem with cam timing as well, but OP said they checked that.
Maybe you should check again.

[miljan]

timing is 100% ok. fuel pressure is 3 bar. I saw the cracked hose between MAF and turbo. I replaced it. the same happens again. After that replaced the MAF. after 1 min on 3000 rpm exhaust manifild red but less than before. This problem is partially solved. vems coming soon and I hope that these problems will not be back.

[prj]

No ECU in the world is going to fix mechanical problems with your car.

[Thuppu]

Havn't tested my self, but maybe it's normal that the exhaust manifold is red after 1min @ 3000rpm..? If all works fine, why is this a problem? Where does cast iron start to glow... 500C ->

[driftin jo]

Doesn’t matter what the emitting material is, cast iron, stainless steel, tungsten in a light bulb, ETC, the temps are about the same for a given colour. Generally accepted colour/temps are

400 Deg C Red heat, visible in the dark
474 Deg C Red heat, visible in the twilight
525 Deg C Red heat, visible in the daylight
581 Deg C Red heat, visible in the sunlight
700 Deg C Dark red
800 Deg C Dull cherry-red
1000 Deg C Bright cherry-red
1100 Deg C Orange-red

[miljan]

car works great. if it is normal for the exhaust turns red after 1 min at 3000 rpm work it is probably all right. thank you very much for your help ...

[prj]

How is your AFR now at idle? Should be 14.7 with warm engine.
If it's not 14.7, and you have no fault codes in ECU, try disconnecting the Oxygen sensor (lambda).
If you disconnect lambda and AFR comes closer to 14.7, then replace Lambda.