Hey all, haven't been around all that much lately but I'm having a bit of an issue with my car. Most of you are probably familiar with the "fuel starvation" issue in 3rd gen sedans, and some of you probably know that my car has undergone some reasonably significant modifications.

My issue is that after upgrading my fuel delivery delivery system with a "larger" in tank fuel pump (400 odd HP Walbro or Bosch unit - can't remember the exact specifics), I'm still experiencing the "fuel starvation" phenomonon when taking right hand corners on less than half a tank of fuel.

When planning the upgrades to my car, I was told by a fuel system specialist that the last thing that I wanted to happen, was to run out of fuel while the engine is on boost - but this is exactly what is happening. I decided against a surge tank, external fuel pump setup after being told that they are noisy, smelly and after being advised by David from RPW that he had never experienced the "fuel starvation" issue with his car, using a upgraded internal fuel pump (apparently they are phisically alot bigger than the original unit).

Anyway, I'm pretty much at wits end, and think I will have to get a surge tank and external pump stuck in the boot of my car early in the new year. I just hope it's not too late to avoid doing permanant damage to my engine internals.

Even though I know that my situation is pretty unique...... if anyone has any advice - I'd be very grateful.

Cheers.

i started to get a lil bit of starvation at top end but turned out to be a dirty fuel filter

i would definatly go for a surge tank if i was u just to be on the safe side after spending so much last thing u wanna do is start goin through engines

Just take it easy till you fix the problem.

I can't remeber what fuel pump G&D put in my car when I got the supercharger (Cittris should know) but its always noisy, even noisier when hot, like a high pitched whine. (I'll post a vid later) Also my car stinks badly of petrol when standing towards the rear of the car, but that could also be cause i think my exhaust is leaking again.

Moral of the story is don't mod magna/veradas :bowrofl:

It will be a walbro pump (the noisy thing) - good pumps but hardly OEM noise levels. Prefer bosch, better made pump, and you can get some absolute whoppers.

The standard tank has a 'hollow' that the pump sits in, which acts like a surge tank. If you are pulling more fuel out than normal (ie. a high flow pump) the return line (IIRC) isn't run back into the hollow, its run into the main tank. You empty the tank far faster than normal, which is why you are getting the starvation issues.

A surge tank isn't noisy or smelly if it is done right. The only reason it would smell is that there is a leak. It also requires that you have it sealed off from the rest of the cabin (magnas don't have split fold seats/hatchback so this doesn't apply unless you have a wagon).

Have you considered fitting a baffled tank from a ralliart?

Cheers
Heath Young

Have you considered fitting a baffled tank from a ralliart?



exactly what i was thinking..

Have you considered fitting a baffled tank from a ralliart?


I know with 100% certainty that TL's have baffled tanks (one of mine broke off inside the tank) so don't know why the TF would be different?

I know with 100% certainty that TL's have baffled tanks (one of mine broke off inside the tank) so don't know why the TF would be different?

TJ and prior did not have them.. ralliarts were the only ones 2002 and prior... thats pretty cool that they started putting them in the TL's

they're needed... even with the ralliart tank, when its real low and you corner extremelly hard under power it'll cut out. pretty dangerous really... i do find the baffled tank alot better though..

If that's the case then - drop past your local Mitsubishi wrecker and grab one out of a smashed TL if they fit!

If that's the case then - drop past your local Mitsubishi wrecker and grab one out of a smashed TL if they fit!

Thanks for the info on the later model fuel tanks guys - I'll definetly investigate it. Anyone know whats involved in swapping out a fuel tank?? and how much a 2nd hand one might fetch?

wats this baffle ?? like a little section where the fuel pump sits in ??

I know with 100% certainty that TL's have baffled tanks (one of mine broke off inside the tank) so don't know why the TF would be different?


Really? Then why does my car suffer from this symptom to???? My VRX must have a 'lower class' tank in it then :nuts:

wats this baffle ?? like a little section where the fuel pump sits in ??


Baffles in tanks are bit's of alloy of a set height welded or cast in the tank with that creates a sort of slalom for the fuel to take when cornering hard, it helps prevent the fuel going away from the fuel pump, hence no fuel pickup

Really? Then why does my car suffer from this symptom to???? My VRX must have a 'lower class' tank in it then :nuts:

you may have them cause even with them mate, you'll still get cutting out problems on low fuel when cornering extremely hard... like i said though it tonnes better with them... with a 1/4 tank or less in my TJ Sports i could get it to cut out (this was with coilovers though haha)

my ralliart needs to be on Empty for this to happen so the baffles do help

Really? Then why does my car suffer from this symptom to???? My VRX must have a 'lower class' tank in it then :nuts:

:stoopid: but only when my tanks under 1/4 full

:stoopid: but only when my tanks under 1/4 full


It happens when it's under 1/2 exactly like my TH did.

All TE onwards magna fuel tanks had baffles in them, the difference between the standard tank and the ralliart tank was the fuel reservoir, this part of the tank is what the fuel pump sits down into. Its approximately 300mmx300mm with a straight open top (it looks abit like a 2litre ice cream container), it is spot welded to the bottom half of the tank, whilst the "baffles" are spot welded to the top half of the tank, both of these operations were done before the 2 halves of the tank were seam welded together.

The difference between the standard magna and ralliart fuel reservoirs was that the ralliarts was rotated 90 degrees and had a 30mm wide half rolled over lip on the top, so that when the fuel level was low (under half a tank) and a corner was taken hard the fuel would hit the side of this reservoir and go up the side, hitting the rolled lip which would inturn "push" the fuel back down and keep it inside thus helping keep the pump sumerged in fuel.
The standard tank which didnt have this lip would just let the fuel slosh out of the reservoir and into the main part of the tank thus staving the pump momentarily and causing the dreaded fuel surge problem.

I know this from driving the first prototype ralliart mule/development car (whilst another person observed what happened with the fuel when the tank was under half full) that had a clear perspex cover sealed into the tank so that we could see what was actually causing the fuel surge problem then after discovering the source of the problem this revised fuel reservoir was designed and used in the ralliart fuel tanks.

Hope that helps explain the issue a bit better black beard but if you have any more questions about it feel free to PM me :)

well there ya go.. learnt something new.. cheers jason

why do i remember reading in a ralliart magna review about adding baffles to the fuel tank though? hmmmm review writers talking cr@p?

Wouldn't it suck to be the person in the boot with a torch watching the fuel through a perspex cover while someone corners hard! :bowrofl:

Very interesting though...

Cheers
Heath Young

Black Beard,

You may / may not be aware that there is a Ralliart being wrecked in NSW (Campbelltown)

Here are the details:

Just thought some of you may find this of some interest.
Franks Auto Parts in Cambelltown have just purchased a damaged Ralliart Magna which they are wrecking.
These Guys are really good and helpful and will ship throughout Australia.
They are keen to help out anyone from the AMC.
If you would like to know anything else you can contact Todd on ph 02 4628 5555 or by email on todd@franks.com.au

I saw an atricle in one of the local magazines (maybe Zoom) where a bloke had a small external surge tank made up for his Commodore. The tank was sized to last for bursts of really hard acceleration (I forget the exact time). They made the tank to mount up under the car, not in the boot. I remember that a fairly normal pump was used to transfer from the factory tank to the external surge tank. Then high capacity pumps were used from the surge tank to the fuel rail.

I think that the return line was plumbed to the surge tank.

Do you want me to look for the article?

Ken