Typer Jim

Have had a nightmare... Was advised to upgrade the fuel pump on my Type'R' to a Walbro (cant remember model number), which i did just about straight away.

Instantly i noticed a reduced fuel consumption from getting 280 miles from a tank to getting around 200-220 a tank. Initially i put this down to being heavier with my right foot.
I was also noticing a smell of fuel when i had bin giving the car a hard time, this was something that concerned me so i planned on getting it looked at.

Then, this morning the engine started miss firing! As you can imagine i was distraught. I instantly took it down to the guy that looks after my car to see what the problem was.

After extensive investigation it was found that the fuel pump was overfuelling the engine which has caused the spark plugs to become clogged with soot. This has really p****d me off because there were many people telling me that a Walbro pump was the way to go and it obviously isnt. When phoning the company where i bought the pump from they said that i needed to upgrade the pressure regulator (and hope this solves the problem i suppose).

Here are a few questions that i have:

1. Why would Subaru spend millions of pounds developing these machines and then use fuel pumps and pressure regulators that need to be upgraded.
2. What evidence is there that the standard Subaru pump isnt any good and should be replaced?


Well, i have installed the origional fuel pump to sort out this mess and it looks like i am going to have to replace the spark plugs too. So this has probably cost me around £200 when the car was absolutely fine as it was... This may have caused other damage to my engine and if this is the case heads will roll Will be going back for a refund of the Walbro me thinks.....

My advice for people who arent sure on mods, dont do them. These cars are awsome standard so leave them alone.

Not a happy bunny

Rant over

flat4_ire

why did u upgrade the fuel pump?? im running an si type r with a few mods and still have standard fuel pump, running grand, u just got bad advice, uprated fuel pump is not an essential mod unless ur going up a fair bit in power

Typer Jim

Yeah i know, wish i had never listened to anyone and just trusted Subaru. Never mind, lesson learned. Good to hear someone running standard pump with no problems....

justanotherperson

is it a case now that you need the upgraded pressure regulator because you have a stronger fuel pump?
for example, the standard pressure regulator was fine for the standard pump ?
and who told you that you needed an uprated fuel pump was it a reputable company or just a comment from off here ?

flat4_ire

gimps man, only listen to a few, my type r has equal length headers, full decat exhaust with apexi ecu mapped by andy forrest, runs absolutely fine with standard pump, it wud be next upgrade now though if i was keeping her

Typer Jim

I am being told that i need to upgrade the regulator to solve the problem with the upgraded pump that i have.

I was advised by a local company who is normally very good and also advice of the forums......

flat4_ire

Clowns

andypugh2000

My 98 uk turbo is running 312 bhp on the std pump. std injectors, std map and std engine etc......shock horror i have not listened to the "get it remapped" brigade because i have changed the zorst turbo boost etc, biggest load of old tosh i have ever heard. Oh and just incase you were wondering how long till it blows up....it has done 95k so far and 30k with these *unsafe* mods

Trap2Terrorist

iTrader: (3)

I upgraded my bugeye WRX with a Walbro 255 for my ecutek remap at Powerstation. They recommended to me to have it upgraded as a safety measure to ensure my car doesn't suffer from fuel starvation due to the increase in power.

I imagine they know what they're talking about.

Also, if you do a search on SN you'll find that there have been cases of engine damage and failures that have been attributed to fuelling issues caused by the standard oe pump.

RAF1

iTrader: (5)

I always assumed it was the imports that needed a remap for uk fuel - not the uk models.............?

Raf.
p.s. also very confused on what to get done and not get done on my Type-R (When i find one.>!! )

Trap2Terrorist

iTrader: (3)

Remapped for a power increase, not fuel type

Typer Jim

Dont really know where to go from here, have spoken with a guy who has years of experience with subaru, and even spoken with Prodrive and they both say that the standard pump is fine, yet i am bombarded on the forums with people saying that upgrading the pump is a must....

My head hurts

Typer Jim

The Type'R' that i have was imported by Prodrive brand new and they never remapped for uk fuel for whatever reason. The car has always been run on optimax with no Octane boost etc.

As for mods, unless u r planning on track days i would leave it standard and enjoy one of the best imprezas made in its origional glory!!!!!!!

crispyduck

iTrader: (1)

Sounds like you've had some bad luck. Personally I feel that a lot of the advice on here appears to be from people's real experience. The hard thing is to weight this against the current state of tune of your motor.

For fueling I would have thought the descision was simple - measure the duty cycle of your injectors. If they are running at 100% under load and WOT, then perhaps upgrade the pump. If they max out say at 95%, then leave it standard for now. I'm still learning in this area so hope that this rather simplic advice is correct!

I appriciate that not everyone is able to monitor this information and some mods are performed on a tight budget, however it need not cost the earth. I'm currently writing up how I'm monitoring the ECU for less than £50. If you're interested let me know and I'll drop you a link when I'm finished adding what things you need to look out for in the diagnostics output.

-Steve.

Trap2Terrorist

iTrader: (3)

You may find that a Type R has an uprated pump anyway. I upgraded my bugeye pump with the Walbro but a guy ("Blue Dragoon" on SN) I know upgraded his with a second hand STi pump (IIRC).

Failing that you may manage to get hold of a second hand or even unused pump from here or eBay. I searched eBay for weeks prior to buying mine hoping to get one for less than £100 but couldn't get one. In the end I bought it from flat4online.co.uk for £90 inc shipping and they were the easily cheapest I found.

Sods law - a couple of days ago the exact fuel pump I was after (brand new Walbro GSS342) went for £62 + £5 P&P on eBay .

Typer Jim

Well have sorted out the misfire, was down to the fuel pressure reg, have bought one from FSE and replaced the pump with the walbro that i bought.... Looks like i was unlucky with the reg going at the same time as me fitting the uprated pump so i take all i said back and am eating humble pie.


Now my MAF has gone, can you believe it!!!!!!!!!!

JTaylor

Glad you got it sorted Jim.

TonyFlow

IIRC, the reason for replacing the pump in classic STi's was that some were found to not provide enough fuelling (i.e. were faulty) and hence run the engine lean (not good).
Changing the pump should not make you overfuel, as the FPR should supply the same pressure of fuel?

Pedroskate

Jim
I like to work only on facts, so this is what I've learned about fuel pumps (which I'm sure someone will take great pleasure in telling me.....is wrong!).
From all the questions I have asked, I am led to believe the standard subaru fuel pump is rated at 125 litres/hour. From an article I read in a US Drag Racing mag, litres/hour x3 = aproximate maximum achievable flywheel bhp. Which would make the standard pump good for 375bhp (less a percentage for deterioration due to age). So for any scooby ever produced in standard spec, in theory it will do the job. However, acording to the forums, tuners that have witnessed the AFR leaning out at the top end as the pump fails to maintain the required presure, so there is a problem.
The Walbro pump commonly substituted is the ITP-255, which at 255 litres/hr is theoretically capable of 765bhp!!!
There is another Walbro pump supplied as a scooby replacement, the ITP-160, which at 160 litres/hr is theoretically capable of a 480bhp.
Draw your own conclusions, but I'm not convinced the 255 is a suitable replacement.
If anyone knows this formula to be wrong, tell us what the correct formula is so we can all make the right selection.

On a separate note, did your fuel consumption improve with a new regulator?
Pedro

Typer Jim

I have just finished at AJ and had a new MAF sensor put on. This has sorted out the engine running rich so all is good again. Dont know about fuel consumption yet as havnt had chance to run it, i will let you know tho.....