Boost stops at 1.4bar - N75?

[hunker7]

List of things I've tried.

• Boost test (leaks fixed)
• Checked all clips
• Checked N75
• Done output test

[hunker7]

Just checked the ECU, that is all fine too.

MAP sensor isn't dead as it reads 1025mbar and TPS works fine too.



Only thing I can do is leak test it again.

I have noticed that car runs rough when idling. Gear-stick is visibly shaking, and if you put hands on the dash the whole car shakes. Nothing like that in my dad's Octy, can't even feel the engine running on his... don't know if that's how it should be, or, knock sensor is half dead and limits the boost.

[hunker7]

So, I might have found the problem. Looked at one of the UrS4boy write ups about altitude sensor, and Bentley manual says

What the Bentley Manual says about the F96 is: with the three pin connector disconnected and with the wire bale up and the notch in the connector down, the three female connector pins are, left to right, 1, 2 and 3. With the ignition on, you should get 4.5 to 5.5 volts between pins 1 and 3 and pins 2 and 3, if not, there is a voltage issue related to the ECU. The only mention of ohms is 1 ohm maximum.

Between pins 2 and 3 I am getting 5v, but pins 1 and 3 it's only 3.98v.

[mike74]

try unplugging the lambda sensor when idling and see if its any different. did you ever check out the altitude sensor btw?

[hunker7]

try unplugging the lambda sensor when idling and see if its any different. did you ever check out the altitude sensor btw?

Look above

[mike74]

beat me to it!

[hunker7]

beat me to it!

What now? It says there is problem with ECU voltage, is it fixable?

[mike74]

Not sure about the voltages im afraid. I just checked mine out using the resistance between pins 1+2 and found it was waaay above 1200 ohms. have a search on here and im sure you'll find some info

[hunker7]

Not sure about the voltages im afraid. I just checked mine out using the resistance between pins 1+2 and found it was waaay above 1200 ohms. have a search on here and im sure you'll find some info

About that, I couldn't get resistance reading between 1 and 3, and between 2 and 3 it was something like 1080 Ohms

[mike74]

in fact here's the post that helped me sort my one out. its really easy to do if not a little fiddly getting the resistance correct (trial + error...lots of errors )

http://www.s2forum.com/forum/showthread.php?t=2899&highlight=barometric+ohms&page=2

[hunker7]

in fact here's the post that helped me sort my one out. its really easy to do if not a little fiddly getting the resistance correct (trial + error...lots of errors )
http://www.s2forum.com/forum/showthr...ic+ohms&page=2

Thanks buddy. I've checked the sensor itself

Across 1 and 2: 1290 ohm
Across 1 and 3: 2850 ohm
Across 2 and 3: 2400 ohm

That means the sensor itself is fine. But ECU isn't giving the right voltage to the sensor, is that it?

[mike74]

Not sure mate. It might still be worthwhile 'adjusting' it so resistance between 1+2 is LESS than 1200 ohms (just a smidge). I set mine to 1180 ohms and regained my missing 5psi boost.

[hunker7]

...on my way to do that

[hunker7]

I got mine down to 1150ohms, see if it works, if it does, will take my time to set it to just under 1200ohms

Wish me luck

[UrS4boy]

in fact here's the post that helped me sort my one out. its really easy to do if not a little fiddly getting the resistance correct (trial + error...lots of errors )
http://www.s2forum.com/forum/showthr...ic+ohms&page=2

Wow. Did not know that. As I was reading, I was thinking, how did I miss this? Then I checked the date of the post. 2004. Okay, not crazy. I only showed up here in Feb. 2006.

Good info. Going to steal it and add it to my F96 post.

Thanks.