stock R34 GTR high EGT ?

[bigboss59400]

Hello,

 

During highway around 3000rpm I'm at around 840 in sixth gear.

During a WOT second gear to 4th gear I'm at 960 and I stopped at this point... (MFD starts to warn me)

Engine iddling I'm at about 550

I didn't pay attention in the past to this as I was solving others issues...

The car is fully stock, everything seems to work good

 

It looks like the engine is running too much lean ? Should I make some log data for the AFR ?

I suspected the fuel regulator and the fuel pump to be 22 years old....Is it probably the issue ?

 

THanks for your inputs

[syd_gtr]

I had this issue and it turned out to be massively wrong timing making the exhaust valves open too soon. The tuner had seen too many rb26s of all kinds and I think they forget what stock is supposed to be like. They just said to me dont worry about it, metal doesnt melt at that temp.

timing probably isnt your problem just saying that you know best that it has changed, so get to the root cause.

[GTSBoy]

Could be cam timing, as above, ignition timing (too retarded) or lean. All are bad.

[bigboss59400]

Thanks for your reply 

So for you it's not related to the fuel pump and fuel regulator 

What temps should I see on the highway idling at 3k in 6th gear ? 

So maybe the CAS is wrongly set, I will remove some advance to see

thanks 

[GTSBoy]

On 8/1/2021 at 9:25 PM, bigboss59400 said:

fuel pump

could cause lean.

On 8/1/2021 at 9:25 PM, bigboss59400 said:

fuel regulator

almost never fail in any meaningful way.

My 25DET Neo will cruise at ~400°, pre-turbo. Literally in the turbine inlet. Max load is ~900°C.

[bigboss59400]

So I try to set the ignition to 15,20 or 25 doesn't make any difference..

I have 2.6 bar at iddling on the fuel pressure line (taken after the fuel filter)

I have 3.0 bar when removing the vacum hose or during the next 5secs I put the ignition on

The fuel pressure is between 3.0 and 3.5 bars under WOT

The fuel pressure is droping slowly continuously a bit after I switch off the car

According to the service manual, these values are ok meaning pressure regulator and fuel pumps are ok

I don't know what to do/test...

The car is fully stock, seems to be in good health (no suspect sounds or lack of power )

Any suggestions ?

[joshuaho96]

Log AFRs, get a timing light and test your base timing, pull the timing cover and look at whether all the timing marks line up. One of those things will probably tell you what's wrong with the car.

[bigboss59400]

On 8/14/2021 at 8:13 AM, joshuaho96 said:

pull the timing cover and look at whether all the timing marks line up.

what do you mean by that? 

thanks for your reply 

[joshuaho96]

On 8/14/2021 at 10:51 AM, bigboss59400 said:

what do you mean by that? 

thanks for your reply 

It means check the mechanical timing of the cams relative to the crank. The belt and the engine itself will have alignment marks so you can verify this: 

 

[Ben C34]

On 8/11/2021 at 10:28 PM, bigboss59400 said:

So I try to set the ignition to 15,20 or 25 doesn't make any difference..

Man, adding a Heap of timing is a brave move. I hope there was no WOT action while doing that test

[bigboss59400]

Thanks for all your input guys 

It looks like the exhaust cam timing is wrong ...(1 teeth off )

However when putting the engine at its top dead center 

the admission cam is 0.5 teeth off and so the exhaust cam is 1.5 teeth off 

Does it means that the timing belt pressure is wrong which explains the 0.5 teeth difference?

Thanks for your time 

[bigboss59400]

So end of the story 

by setting correctly the timing belt everything Line up correctly 

The car is now running much better !!!

I couldn't go above 800 degree on medium/hard road drive 

I'm so happy 

thanks for all 

[joshuaho96]

On 9/5/2021 at 2:26 PM, bigboss59400 said:

So end of the story 

by setting correctly the timing belt everything Line up correctly 

The car is now running much better !!!

I couldn't go above 800 degree on medium/hard road drive 

I'm so happy 

thanks for all 

You should probably verify your base ignition timing and do a compression test before you celebrate. 

[bigboss59400]

Yeah I

So to conclude compression test is between 100 and 105psi (full throttle, battery charged )

I always noticed that the high rpm didn't felt powerful

So maybe it has been damaged due to the high temp or not

Anyway it's fine for me at the moment I will leave it as it is

Thanks for the help and suggestions !