MKC

I have a UK MY99.

Its had 4 engines (from Subaru) since Nov 2001 (no mods).

The latest engine has lasted longer than the rest
(see previous posts) after the ECU was replaced.

I have noticed (in the past) that if the tank registers less than quarter of a tank (on or below last white line) that going fast around a roundabout affects the cars running for a few seconds to several minutes. Does this mean anything ? Can a fual pump be didgy and only show this when the tank is low (nowhere near empty)?Is there any explanation (technical if possible)?

Cheers....

MKC

hades

Going fast round a roundabout with not much fuel in the tank will cause "fuel surge". The fuel all goes to one side of the tank rather than next to the fuel pick-up, and therefore, the pump picks up air for a second. The car will stutter as there is no fuel to make it run. Normally, this should only happen for a second or two, not several minutes.

One possible consequence of this lack of fuel pressure is that the engine will run over-lean for a short period. If you are on high boost, and running over lean, it could cause over-high in-cylinder temperatures, and possibly det. Not advisable or good for engine life.

Unless you're fuel surging on a regular basis, though I can't see fuel surge should have blow four engines that quickly.

Hope that helps a bit. There will be people on here with more knowledge than me that may be able to help more.

LG John

Leaving asside the whole 'joke' side of fuel surge for a minute - any time I've had it its scared the cr@p out of me from the damage point of view. As I've said in the past my car seems to get it under full boost and it gets it very violently. I can't imagine its good to have all that air being rammed into the engine and then suddenly no fuel to ignite with it!?! Has there been any proven 'fuel surge' damage?

MKC

Thanks for reply so far. Please note that when I say less than a quarter I mean just a bit under. I do not go anywhere near the red. MKC

dowser

Mark,

Fuel surge should only be apparent during hard right hand cornering - when it happens you get off the gas quickly. By the time you re-apply gas the problem should have gone (assuming the corner has finished).

If, after the above, it hasn't gone then you have a problem, and it *could* be the cause of your failures - while the occasional fuel surge is OK, extended loss of fuel delivery quickly builds up heat enough to melt stuff.....

I don't know how a healthy car reacts to fuel surge if you stay at WOT, I'm not that brave - I'd suggest this also isn't very healthy and would advise any fuel cut (surge or overboost) should have an immediate 'foot off the gas' response....quickly!

Richard