Boost Creep After Installing Walbro 460

[drifta1600]

Im soon to be going apexi power fc and e85 tune (when all my gear arives) . but ive started with the fuel pump. (walbro 460l/h e85 series)

install went well, took 1h20m

but before i had my hdi set to 10psi, and was very satable,

but now, shoots to 10psi, sits there untill 4500rpm then creeps up to 14/15 psi

ive had to back it off to 7psi so it creeps to 11.

mods:

hdi ebc

blitz FMIC

decat

bell mouth dump-full 3inch exhaust

iridiums with .8 gap

splitfire coils

hks pod

drfit boost gauge.

any ideas as to why it does this will be nice!

Thanks

[GTSBoy]

Mixtures have changed. What was the pump that your replaced?

[drifta1600]

just a stocker

[Ben C34]

You had an issue before the fuel pump change.

[drifta1600]

what was the issue do ya think?

[Ben C34]

I would have thought you could figure that out

[drifta1600]

well, it was running perfect before i changed the pump. i would have thought that the mixture wouldnt change because it still has std injectors and fuel pressure reg.

so, any one with a solution untill my apexi arives? it will be a good couple of months before its installed and tuned.

[GTSBoy]

That's the point isn't it. The standard mixtures are very rich up top. Well, they are when you have the BRAND NEW standard pump and reg. But add 15 years onto the pump and now it doesn't want to keep the pressure up when it's flowing at high loads and your injectors actually see lower pressure than intended. The mixtures are a bit leaner, the car goes really well. Everyone is happy.

Then you install a big pump that can keep the pressure up at high flows, and suddenly you're hosing fuel into it at the top end.

[drifta1600]

ahhh right :-) makes scence! thanks gtsboy. so there is probably no solution for now. i just have to wait!

[drifta1600]

just another thought, shouldnt the ebc controll the boost. it wont let it go past 11psi if i set it at 7... so obviuosly the wate gate is capable of doing its job, as it can stop the boost from going past a certain point!

[GTScotT]

As above, theories are correct.

The EBC is only a cheapy, too. I have one I am going to install soon and I do not expect it to do that great a job of holding boost. Now that the mixtures have changed the EBC accounts for a different result.

Try disconnecting the EBC and just running actuator pressure, see if it then holds stable

[drifta1600]

yer true. ok will do. thanks mate.

dont know how its all going to cope with 250rwkws. lol

Edited September 3, 2013 by drifta1600

[533 RYC]

I recently fitted a GFB G-Force II. Has some fairly good features: overboost, gain, sensitivity. Very happy with it. Fairly easy to set up if you have a highway or dyno nearby. Responds very well in situations I get myself into.......

[drifta1600]

did you get your gfb after trying a different ebc? if so, was there a big improvment?

[533 RYC]

No, its my first. Had a cheap manual unit. Will NEVER go that road again! Too uncontrollable. A dual solenoid unit would be better than the single, but couldn't afford $600+. Was thinking about the turbosmart e-boost street, but I still saved $200. I got it from eBay from MRT Performance.

[drifta1600]

Well, I've bought gfs one now. Hopfully its better thAn the hdi one. The programing seems like it should help. I've just bought a hi flow turbo so, ill be doing a few upgrades now, so well see how it goes.