Cut Off At 15 Laps On Track Days

[dxbgts33]

Nissan R33, GTS NA 1998, running very nicely, after 15 laps, power loss and no response from throttle and behaves as if fuel starvation. fuel pump sounds as if running full capacity (screaming) and will not rev over 2000RPM. Have to turn off and restart to get to pits.

If car is allowed to cool down for half an hour, can get one full lap with full power then fault recurs

fuel pump is an uprated wallbro, new fuel lines, filter, tank full.

No fault codes pop up, no over heating, car runs fine and very strong

[Thunderbolt]

Sounds like it is going into limp home mode. Walbros tend to get loud when the voltage isn't as great as it should be, however if the battery or alternator was at fault, I would expect it to cause problems at other times too. Did you earth the Walbro to the body, or are you relying on the factory earth?

[dxbgts33]

Sounds like it is going into limp home mode. Walbros tend to get loud when the voltage isn't as great as it should be, however if the battery or alternator was at fault, I would expect it to cause problems at other times too. Did you earth the Walbro to the body, or are you relying on the factory earth?

No I haven't earthed the wolbro to the body, just did all the connections and dropped it into the tank. should that be a problem? trying to look at the manual to check ur point.

[dxbgts33]

Sounds like it is going into limp home mode. Walbros tend to get loud when the voltage isn't as great as it should be, however if the battery or alternator was at fault, I would expect it to cause problems at other times too. Did you earth the Walbro to the body, or are you relying on the factory earth?

I found this is the manual, but it doesn't elaborate. file attached. another member on another post had this to say:

"sounds like you'll need a surge tank.

not really a common issue - but it does happen. i have no problems without one and i would think that i hold more sideways Gs than most people.

15 laps is a fair bit though, i would hazard a guess that the tank would be no where near full."

another friend of mine asked to check the fuel return line as that may be blocked, therefore making the pump run lean

skyline.doc

[Thunderbolt]

No I haven't earthed the wolbro to the body, just did all the connections and dropped it into the tank. should that be a problem? trying to look at the manual to check ur point.

fuel pump wiring topic here:

http://www.nissansilvia.com/forums/index.p...howtopic=150876

I am not familiar with Skylines, so not sure if all the issues that are in there are applicable, but you may be able to get some benefit from the topic.

Edited April 9, 2008 by Thunderbolt

[dxbgts33]

fuel pump wiring topic here:

http://www.nissansilvia.com/forums/index.p...howtopic=150876

I am not familiar with Skylines, so not sure if all the issues that are in there are applicable, but you may be able to get some benefit from the topic.

Thanks for that. All topics on the forum are leading to the Air Flow Meter. The symptoms the car has look like an AFM problem. Spoke to the garage here and he said the car runs ok after switching on and off again because the computer erases the memory reading, which explains why the car takes me to the pit after switching off and on again. If it was fuel related, the problem might remain constant.

Another thing is that the standard fuel pump did the same thing. When I upgraded to a walbro the problem persisted. Will install my friend's AFM and see how it does. If problem persists I will look at the return fuel lines etc.