You'll have to excuse me because I've never felt fuel surging so I can only assume. OK I'll start off my mentioning I had my car tuned 3 days ago (Bosch 42lb injectors), all clamps under the bay are tight, boost solenoid is clean. At 2000rpm with a bit of load on the throttle the car surges as it comes on boost and the revs fluctuate between 2000-2500 for a few seconds and the turbo can be heard pausing in between spooling up. At first I thought it was a tune fault as it did it on the way home 1/2 tank of fuel at 100 when I nudged it a bit to overtake (5th gear D mode). It also started doing it at 60 today if you make it drop down a gear to 2500rpm area. The car behaved like this only once in standard form some time ago accelerating to 60 a few times but am unsure if I was low on fuel on that night.

I filled up a full tank and the problem could only be felt about very slightly (wouldn't have noticed if I didn't have my eye on the tacho) then I nailed it going up a hill and it stopped revving at 3000rpm like it had a rev limiter there? Could it possibly surge like that with a full tank of fuel?

Have u changrd fuel filter latly?

Doubt it's fuel surge on a full tank or at 2000rpm.

Does the dyno sheet have a dip in the power at those revs?

Is this the FG we tuned earlier this week?

Any car issues may show up worse after the car has been tuned and really should have been rectified before tuning, or at least mentioned at the time, we have had some customers think a tune will solve all their issues, in some cases it may put a band aid fix on it but the real problem needs to be addressed.

The car may need to go back to the tuner, whether it was us or who ever tuned it, to be looked at, explain to them exactly how you can reproduce the problem to make it easier to diagnose/repair.

Another thing to possibly so is to fit the stock injectors and flash the stock tune back into it to see if the problem is there stock and then go back to the tune and injectors.

Fuel surge does not normally happen with a fuel tank, unless the pump is not keeping up (faulty)

Plugs or coils?

Fuel filter has been done also, it has 24,000kms so I doubt spark plugs/coils but will check nevertheless. Yes Mick it's me from Monday, I rang up yesterday and left a message with Bel. Pre-tune it only occurred once in a less excessive form a few months ago probably around March? The fact that the issue lessened with a full tank is weird though...I'll keep troubleshooting and pop in when you have time available Mick.

Hi Joe

We have seen 1 FG that the fuel pump failed, not die completely but just started to get less flow to where the car would surge etc, but the fuel level should make no difference to this.

If the fuel level is affecting things it sounds like fuel surge, but there are other things that may give similar feel.

It may pay to pull the pump out of the tank and make sure there is no splits etc in the pick up hose and the pump is picking up from the bottom of the tank, either of these could explain fuel surge.

Edited July 22, 201115 yr by ratter

Will do it when the fuel level gets low again Mick thanks. Any insight on why the car cut at 3000rpm on the hill? Maybe it is the pump, I've always been able to hear the fuel swishing in the tank at anything under 15L remaining don't know if that's normal in a Falcon.

Edited July 22, 201115 yr by FG50T

God! Your hearing must be good!

again I'm totally guessing, but the angle and possible pick up problem may have contributed to it????

There could be other explanations to your problem that are not fuel related, but if the tank level is causing it change that's what needs to be looked at first