GTR Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
207 Posts
Discussion Starter #1
Background

R33 GT-R, with quite a few engine modifications and single turbo conversion

The issue

Hey, I've seen this issue occurring a couple of times on this forum but couldn't really see any technical information that would help me. Basically, cold start is great EVERY time, no problems however whenever I stop after the oil reaches operating temperature I cannot start the car until the oil cools back down to sub 60 degrees.

The suspected problem

I've been told by a good source that it's vapour lock due to the fuel recycling back to the swirl pot and getting hot however the last time this happened, I checked the swirl pot and it was cold. I'd been driving 10 minutes.. 5ish miles to the fuelling station where I topped off. I've also run with a bin bag of ice over the swirl pot and fuel pumps/lines/filters so they're staying pretty cold, however the issue still persists.

What does make me believe that this is the issue is that if I drive quite hard prior to turning the car off, which I'm not too happy about doing because I want proper cooling of the turbo, the car seems to start ok, or doesn't give me the problem every time.

What have I tried?

Checked air and water temperatures using FC-Edit which are showing correct values so I don't believe that there is a sensor fault. The fuel pressure and oil pressure seem to be well within normal ranges once I get the vehicle started.

What am I going to try?

I'm going to test the coil packs, compression and igniter tomorrow but I'm not sure how exactly to test an igniter so any advice would be greatly appreciated. Failing that, there could be a problem with the ECU mapping so I'll take a look into that.

I'm thinking a fuel cooler might work but if a bag of ice on top of the fueling system isn't working then I'm dubious as to whether a fuel cooler would.
 

·
Registered
Joined
·
207 Posts
Discussion Starter #2
Fixed, was cranking ms on the ecu software, all starting perfectly with a tweak to the map.

Thanks!
 

·
Registered
Joined
·
207 Posts
Discussion Starter #4
Yeah, it's really peculiar that she wouldn't start when hot but would when cold. From my experience, it's usually the other way around, so it was either vapours lock, a sensor/electrical issue or one of the ecu settings not correct. The 80deg/50deg settings for cranking ms on the apexi power-fc software were at 5 and 8 so now they're increased a little based on the fuelling system and starts up beautifully after a single crank.
 
1 - 4 of 4 Posts
Top