Was pootering along in 5th hopping up to 100mph then suddenly the surge reduced - slowed down and went into boost in 4th, only boosting to 5-6spsi :chris:

 

No missfire, engine running smooth, not overheating (according to the gauge) - what's the standard checklist?

Firstly you need to run an ECU check for error codes :

 

There are 2 methods :

 

http://www.ttzd.com/tech/diagnostictech.html

 

http://www.twinturbo.net/ttnetfaq/FA...agnostics.html

 

Normally safety boost is caused by a problem in the det.sensor area (either genuine det detection / faulty sensor / sub loom 2 sensor) or a problem in the temperature sensor area (faulty sensor / poor connection / damaged loom)

Don't dismiss a combination as well.

If you have a faulty temp.sensor or bad connection etc, the ecu thinks the engine is cold and limits power until it sees normal running temp.

 

FYI there are 2 sensors just behind the fan in the water pipe in front of the cam cover. The LEFT hand sensor is the one that can generate a code 13 fault and cause safety boost. Check the connection. The right hand sensor purely drives the temp.gauge on the speedo and does nothing else.

Edited July 29, 201015 yr by turbocraigy

Check the ECU diag codes http://www.300zx.org.uk/ecu_codes.htm how to on this page http://www.300zx.org.uk/diagnostics.htm

yorkshire 1 jupiter 0 :)

Thanks guys, will give that a check tomorrow morning... question -does anybody have a picture of where the diag port is in a uk car? I looked at the far left under the flare/dashboard, there's 2 white plugs above each other, not sure if it's one of those

Far left??

 

On my Jap spec the port is far right above your right knee if you like. Just above bonnet pull. Is grey and rectangular.

Ah right! Wouldn't have thought theyd have switched the loom between american and jap versions.. acctually that makes sense with the ECU being on the opposite sides. Thanks! I'll give it a crack in the morning - it got to be on 2nd ign. ?

No error codes, but just a thought... I had a bee*R on the car until today, 2 of the wires tap into the CAS wires, if one got slightly loose could that trip it? Once I run it again last night the car was boosting fine. I'm thinking I'll get some colder spark plugs and some higher octane fuel in future just to make sure it's not detting.

No error codes, but just a thought... I had a bee*R on the car until today, 2 of the wires tap into the CAS wires, if one got slightly loose could that trip it? Once I run it again last night the car was boosting fine. I'm thinking I'll get some colder spark plugs and some higher octane fuel in future just to make sure it's not detting.

 

I can imagine loose wires on connectors would cause a problem...

 

But when you say higher octane fuel, what do you norally put in it? If you use shite fuel, supermarket especially then you'll get problems. Put proper petrol in it!!!

 

As bad as some bird the other day i saw, local esso petrol station - shitty regular in an R8 god help us!

^ 93 octane, which costs 1.25 a litre. The problem here is I have to travel 60 miles to get super unleaded. And that is 1.21 a litre compared to what we're offered. I can get standard 95 octane and premium 97 or whatever about 30 miles away though. but it's v expensive for the premium - never mind the trip there!

Then it's a uk manual ECU I'm using from John Dixon.. so I figure its mapped for uk fuel. Nonetheless I shouldnt be such a tight arse :p

93 is less than even a standard uk manual should be on 95 minimum! Did u say your car is running increased boost? If so you have an afermarket ecu map - which will be expecting 97 or 99 ron i would have thought. Doesnt matter if its actually on a UK ecu surely, as the original fueling map has been changed to allow for higher boost and more power!