I've suffered recently with fluttering / missfire / holding back at about 4500rpm in higher gears. Accelerating through the gears usually is OK. Then last night I had CEL with MAF warning, Temp sensor so today I've bitten the bullet and ordered

New Bosch MAF
New leads (porsche)
New Bosch coil
2 x Bosch knock sensors
1 x Bosch Cyl head sensor
1 x Bosch inlet sensor
Throttle position sensor
Denso IX22 Plugs

Last month it had 4 x new O2 sensors.
New fuel pump & filters.

Anything else 'while i'm in there'?

Oh, and a switch from 0-40 back to 15-50 along with valve covers.

 

I guess a N75 too... Anyone know the part number?

 

um, overkill much.

 

Bad grounds? Engine loom breaking down or deteriorating?

 

It's not really overkill when you consider the time it takes to change the ignition leads. Buying parts direct from Bosch is typically 1/5th the price from Porsche!

 

O/40 cant be helping can it?

See this thread

https://rennlist.com/forums/showthre...ferrerid=10902

 

ok, but considering how much you are spending on sensors that may be totally fine, I think its overkill.

why not TEST the sensors before replacing the whole lot?

 

Unfortunately sensors don't always just fail open circuit. They can sporadically break down, like the flywheel sensor recently did!

 

should still be able to use an oscilloscope to test sensor function.

 

Well, she's back and WOW!
In the end they did:

New Bosch MAF
New leads (porsche)
New Bosch coil
2 x Bosch knock sensors
1 x Bosch Cyl head sensor
1 x Bosch inlet sensor
Throttle position sensor
Denso IX22 Plugs
Boost sensor
Fuel / Oil / Air filters
6 in Injectors (one was leaking)
6 x inlet manifolds as 3 or more were D shape instead of round!
N75 valve
Air con recharge.
Change to 15/50 oil
Rocker covers & gaskets

I'll try and post some pics. The HT leads in particular looked shot.

Car runs like a watch now. Incredibly smooth in every gear. No flutter or stutter.

I'm running UMW stage 2 turbos with an RS tuning 455 ECU. I have a new RS tuning 475 ECU that caused much stuttering before but may be tempted to try it again.

Would you believe the ABD light illuminated on the way back from the garage! Time to start working on the front.

 

Glad it's running we'll again!
Now what are these rs tuning ecu's? Are they for k24s? Kevin's will give you 475, no?

 

It always ran very inconsistently with Kevin's ECU. It would do a couple of fast runs then that was it for a while. With the RS455 ECU it was quicker and more consistent.
I had my car at 9excellence for about a month with them data logging etc.

I'm not sure of the spec of the UMW2 turbos compared to the RS475 turbos though so may just leave well alone!
The RS455 ECU was designed for near standard turbos though.

 

what did all of this run you, if you don't mine me asking?

 

right, I remember you posting about that. Might do better with the new electronics?


Hey we don't keep track of stuff like that! (the parts list should be enough) Wives have access to computers!

 

I purhcased everything direct from Bosch as I have an account with them:

From memory

Injectors £57 each
MAF £200 (Porsche wanted £1200!)
Knock / Temp etc £30 each
HT leads (Beru) £220
Coil £25
Plugs £30
Thottle position £35
N75 (from Porsche) £40

Labour.... enough

I've been given the permission to use a private mile long runway that's only 500 yards from my house so testing will commence asap. 60-130 etc