R34 Gtr Original Condition Untouched

[The Alchemist]

Situation: workshop with good experience with Skylines and all their associated problems. Has Nissan Conzult software and 4 channel scope.

Vehicle: Untouched R34 GTR with 55,000km on the clock. standard everything!!!!

Problem: running rich like you wouldn't believe at idle and light throttle cruize.

Work done or checked: New Air filter, cleaned AFM's, replaced one dead O2 sensor ( thought we had it but no )dropped exhaust to check for blockage, return line off the fuel reg into bucket to check for return fuel line blockage > ok, New plugs, new coils, checked and flow tested injectors > Mint, checked fuel pressure > mint, checked TPS sensor > mint, checked factory blow off valves for leaks etc etc > mint. Used a can of brake cleaner looking for air leaks > got high but no leaks found. No fault codes, reseting ECU makes no difference. Checked fuel pump voltage regulator function > mint. Checked factory ECU for any mods > none.

Losing many hair follicles by this stage.

I believe all we have left is the ECU but this would be a rare fault.

Has anyone had experience with a R34 GTR with this problem, I realise the ECU is a much more clever unit than the earlier R32,33's and I think its almost like the engines going rich like a fault condition exists between sensor inputs making the fuel settings pig rich for safetys sake but I'm buggered if I know what.

Only odd thing is that the car goes fine when cold in the morning for the 1st 10mins then it all goes belly up once its warmed up.

Any ideas?

Mike

[R31Nismoid]

Well i would have said fuel reg, but you say its right.

Was it just checked @ idle, or driving on the street?

[The Alchemist]

Well i would have said fuel reg, but you say its right.

Was it just checked @ idle, or driving on the street?

At idle and free reving, unfortunately we don't have a 4WD dyno to run it up on.....

Does anyone know more about the fuel strategy and limp modes on the R34 GTR'S and what activates them...

[GTRgeoff]

Just a thought, but try running it without the O2 sensors plugged in for a while. Mine is supposed to eat them (OK 260rwkw on stock computer) and runs best without.

Also could be a leak in an IC hose as it will sense air going through and fuel for it, but not be delivering the air.

[700HP-GTR33]

Have you tried dumping the fuel from tank.......If the car has been sitting for a while

the fuel can go off.

Was it driving fine and this happened or has it always had this problem.?

Cheers

[raz0r$harP.UK]

I had a similar problem with my r32. The fuel reg was checked many times and was found to be working alright. But the problem was that it was intermittently working. It would be worth while trying it with a different reg...

[r33_racer]

is there a vacuum line on the fuel reg on a 26? if so is it split by any chance? Im a 25 man, just taking a stab in the dark haha...ya never know

[R31Nismoid]

At idle and free reving, unfortunately we don't have a 4WD dyno to run it up on.....

Does anyone know more about the fuel strategy and limp modes on the R34 GTR'S and what activates them...

Put the gauge up under the bonnet so you can see it from the drivers seat, go for a drive around the block and slowly come up onto boost.

You certainly dont need a dyno to check that, its very easy and basic to do

Slap it on, drive, see what it does, i think you might be pleasantly surprised to find it isnt happy.

I'll wait to hear back... but if your only idle/free rev that wont show a stuffed reg all the time

[The Alchemist]

Have you tried dumping the fuel from tank.......If the car has been sitting for a while

the fuel can go off.

Was it driving fine and this happened or has it always had this problem.?

Cheers

Has had problem since the owner brought it several months ago. Many tanks of gas later

Thanks for the reply....