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Uprate fuel pump?


merckx

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Do I need a higher capacity fuel pump? I've done a long search but cannot really find any answers.

 

97 VVTI TT, Nur Spec R and full decat.

 

I'm boosting to just under 1.2 bar.

 

Will the original J spec pump provide sufficient fuel? I've read that detonation is a sign of not enough fuel reaching the engine.

 

Could the pump be providing insufficient fuel and so reduce power without you noticing?

 

When reaching max boost I sometimes get a misfire or is this detonation?

 

I'm sure I've got Denso IK22'S

 

If I need a better pump, is the Walbro 342 the one to get?

 

Advice appreciated - Cheers

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Originally posted by mawby

Is it, I'd never even thought of doing it myself. What's involved?

Take spare wheel out. Undo a couple of jubilee clips, pull rubber pipes off, undo huge jubilee clip. Undo huge plastic nut, lift pump assembly out. take off old pump, replace with new one. [HalfordsManual]Fitting is the reverse of removal[/HalfordsManual]
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Originally posted by mawby

Is it, I'd never even thought of doing it myself. What's involved?

 

The only hard bit is undoing the big plastic ring which holds the pump carrier into the tank. Big screwdriver or something and a hammer will be needed.

 

You disconnect the various hoses that go to this which is easy, although you'll spill a bit of fuel so bung a rag in the boot. Then undo the aforementioned plastic ring. Then you can lift out the hanger that the pump is on. Then all you need to do is take the old pump off, attach the new one using the rubber spacer you get with it, connect it up using a new bit of hose you get with the pump to the metal connector. Then you cut the two wires and attach the new plug using the splices you get with the pump (making sure you get the wires round the right way or your pump will suck petrol out of your engine...:innocent: ).

Put the whole lot back, do the placcy ring up again and reattach your hoses, job done.

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OK mate, here's the longer answer :

 

Originally posted by merckx

Do I need a higher capacity fuel pump?

Depends, tell us more.
97 VVTI TT, Nur Spec R and full decat.

I'm boosting to just under 1.2 bar.

Will the original J spec pump provide sufficient fuel?

Probably not.
I've read that detonation is a sign of not enough fuel reaching the engine.
Yes, that is one reason for detonation
Could the pump be providing insufficient fuel and so reduce power without you noticing?
Not reducing power as such but detting - yes.
When reaching max boost I sometimes get a misfire or is this detonation?
Difficult to say without hearing it.
If I need a better pump, is the Walbro 342 the one to get?
GSS342 for a J-Spec, GSS341 for a UK
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Originally posted by merckx

Do you think I should get one then?:D

To be honest mate it's the first thing you should do after decatting. For the price you can get them for nowadays it's simply not worth NOT doing it. It instantly cured my Det and lean-running problems.
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Just wanted to know if I would notice any difference in the way it would run with the new pump.

 

Other than getting one as a precaution or needing one for going further than BPU I searched but couldn't find any definite answers.

 

I think I'll get one.

 

Cheers Jake

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Originally posted by merckx

Just wanted to know if I would notice any difference in the way it would run with the new pump.

 

Other than getting one as a precaution or needing one for going further than BPU I searched but couldn't find any definite answers.

 

I think I'll get one.

 

Cheers Jake

 

Without knowing what your fueling is doing there's no real way of telling. It certainly won't do any harm though! I would definitely change the pump, then get it on a dyno and check your fuelling out. That will give you info for future mods and peace of mind, although you should be fine at 1.2BAR.

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