Running lean on boost
 

Following on from my fuel pressure thread......

My track car is now running lean when on boost, the last map check it had everything was spot on. Whilst on wot the afr was in the 11’s, all the way to the redline.

Since then something has happened.

I got the car on the dyno a week ago today and it now runs in the 13’s when making boost, I’ll attach the sheet.

What would cause this? Where should I be looking?

The only thing I’ve looked at which was last night was the afpr. I removed the vac line and it went to 3.2 bar, I applied pressure using a spare tyre with 1 bar and it went up 1 bar as expected. The vac line appears to be in good condition.

The o2 sensor was replaced before the last map session albeit it was a used one.

Any thoughts?


https://preview.ibb.co/eYV9OS/60_A97...2_A31_AFD5.jpg

What did mapper say

Fuel pump or fpr, he believes it’s not as high as it was but I can’t see how it would have changed unless something has caused it to change. But everywhere it states 3 bar base setting and mine is 3.2 bar and will move accordingly with the amount of pressure that’s achieved.

air leak on boost pipes or intercooler core or leaking dump valve

That would make it run rich generally. Wull go and buy a pump :lol1:

I’m Scottish, which means I’m a tight **** so generally I don’t want to spend money unless I know for sure :lol1:

Funny was going to say don't be miserable :lol1:

The irony of it is......the car was originally for sale and I decided I’ll do a couple of track days whilst it’s for sale and enjoy it before it goes, then the clutch went on the first track day and the rest is history. I’m now at the point where I’ve spent a fair few £’s more than I had planned and I feel it’s getting on top of me.

fuel filter blocked ?