Issues with A/M FPR?

Hey guys, on the way home from the tech day yesterday my zed began acting odd from takeoff.. missing, very jerky from a standstill and was bunny hopping all over the place and popping/blowing smoke out the exhaust.

I pulled over and checked all the vitals, all seemed fine but then I noticed that the fuel pressure was sitting at about 8psi more than I had set on a cold engine. The symptoms were brought on due to flooding with fuel at low revs. I turned it back down again to 50psi and all was fine.

This morning when I started up the car and checked the fuel pressure again from cold, it was lower (about 42psi) so it was now 8psi less than my initial setting of 50psi. When it reached operating temperature the fuel pressure went up to 50psi.

Should fuel pressure be increasing like this on a hot engine? Seems odd as I have been running 50psi for some time without issue until yesterday.

Your thoughts appreciated.

Cheers,

Martin

 

Is you fuel dampener still there (looks like the stock fuel reg on the drivers side of the plenum) When I had my Nismo FPR installed my mechanic deleted the fuel dampener - he reckoned it could cause problems in the future if I left it.

 

Yeah mate, dampener deleted. Do you find your pressures differ when the car is cold or hot?

 

Is your FPR a ''cheap knockoff'' ?

The market seems to be flooded with cheap chinese knockoffs at the moment, and most of them (if not all) are of dubious quality

Sounds like you may be experiencing the consequences of shoddy manufacturing. If you're going to run higher fuel pressure to overcome the limitations of the oem injectors, you really need to be using a top quality Fuel Pressure Regulator.

p.s when you say a cold motor, I assume you mean AFTER your revs have dropped to a normal idle.

 

Your theory sounds likely Ian, idle is controlled manually by an air valve and is raised slightly so remains the same.

 

Martin, I'm monitoring fuel pressure with an in-cabin guage, have never seen it wander as the engine temps changed.
Always consistent. That's with fairly new stock FPR & dampener.

 

Are you adjusting it with the vac line disconnected and blocked off?

Should be ~43psi with no vac/boost on it.

 

yep, no vacuum!

 

Nope - Nismo FPR's are pretty cheap these days ($150ish posted from the states)... Maybe invest in one of those?

 

Check out the PVRV or delete it. If it has been deleted already, make sure it is done properly.