Missing And Surging

[sutty]

Hi guys, been having a problem with the T missing and surging down the strip.It happens about 2 thirds down and does it every time.I have had the valve springs done so that wont be the problem. I thought it might be the fuel pump (which it sounds like) but every one I suggest it to reckons it wouldnt be. I have had it on the dyno to try and find out but nothing shows up. Would be grateful if somebody can help out.

    Thanks.

Hey Ugy,

I found that as the mods progressed and gained power, the more fuel the car needed.

At 280rwkw's, it needed at least 1/2 a tank.

At 300rwkw's about 2/3

At 320rwkw's it had to have more than 3/4 or else it would get the surge you mention at 3/4 track.

No issues now with the surge tank and 800hp pump.

[ugy]

did you do any of these mods after the flasher, and are you running a generic or custom tune

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Hi I got the flasher and custom tune first and then the other mods and retuned.

[ugy]

Hi guys, been having a problem with the T missing and surging down the strip.It happens about 2 thirds down and does it every time.I have had the valve springs done so that wont be the problem. I thought it might be the fuel pump (which it sounds like) but every one I suggest it to reckons it wouldnt be. I have had it on the dyno to try and find out but nothing shows up. Would be grateful if somebody can help out.

    Thanks.

Hey Ugy,

I found that as the mods progressed and gained power, the more fuel the car needed.

At 280rwkw's, it needed at least 1/2 a tank.

At 300rwkw's about 2/3

At 320rwkw's it had to have more than 3/4 or else it would get the surge you mention at 3/4 track.

No issues now with the surge tank and 800hp pump.

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I have 303 at the wheels so the fuel might not have been an issue. Just wondering if it could be the plugs. Bloody annoying when the guys in the other lane were from the red brigade

[Paradoxx]

I reckon it might be the fuel pump if you havent upgraded it already, since you are running bigger injectors they will be flowing a fair bit and the lines may be losing pressure. Looks like it's the only thing left off your list to make your power more reliable. Peace of mind... it's strange it doesnt show up on the dyno though... maybe get it data-logged to see whats happening?

[ugy]

I reckon it might be the fuel pump if you havent upgraded it already, since you are running bigger injectors they will be flowing a fair bit and the lines may be losing pressure. Looks like it's the only thing left off your list to make your power more reliable. Peace of mind... it's strange it doesnt show up on the dyno though... maybe get it data-logged to see whats happening?

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I think you are right. the money involved is not a huge amount for peace of mind.

Looks like a bigger pump.

[boost69]

Even though youve done the valve springs there still exists the remote possibility that you might have a faulty spring int he new set...Im sure if it was a fuel volume issue it would have have been quite obvious on the AFR readouts...

There is a possibility that one of the springs doesnt have the required tension needed, and on full boost is still not able to cope...

Let us know how you go with solving the problem

[Eugene]

Even though youve done the valve springs there still exists the remote possibility that you might have a faulty spring int he new set...Im sure  if it was a fuel volume issue it would have have been quite obvious on the AFR readouts...

There is a possibility that one of the springs doesnt have the required tension needed, and on full boost is still not able to cope...

Let us know how you go with solving the problem

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It sounds alot like fuel pump to me, they ussually dont show probs on the dyno unless they have completly died.

Stick in a Gss341 or 342 Walbro, at least you will know its ok, then put a surge tank and Bosch 044 up on the firwall below the intake manifold, you can run 5 liters in the tank then.

[bugster70]

Stick in a Gss341 or 342 Walbro, at least you will know its ok, then put a surge tank and Bosch 044 up on the firwall below the intake manifold, you can run 5 liters in the tank then.

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Are the Walbro's a straight fit? I thought I read about people having issues fitting them to the stock cradle? And what about the in-tank Bosch 040 - is that an option?

[Adam]

Even though youve done the valve springs there still exists the remote possibility that you might have a faulty spring int he new set...Im sure  if it was a fuel volume issue it would have have been quite obvious on the AFR readouts...

There is a possibility that one of the springs doesnt have the required tension needed, and on full boost is still not able to cope...

Let us know how you go with solving the problem

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It sounds alot like fuel pump to me, they ussually dont show probs on the dyno unless they have completly died.

Stick in a Gss341 or 342 Walbro, at least you will know its ok, then put a surge tank and Bosch 044 up on the firwall below the intake manifold, you can run 5 liters in the tank then.

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Can you use a surge tank combinded with the Bosch 044 with the stock fuel pump in the tank?

If so that would be better than trying to change the in-tank pump on my ute?