Al,

I'm not sure I can wait for the 20th at Agile.

I installed the 3" turbo-back Buschur - no problems at all.

I installed the Walbro fuel pump, and since then; if I 'get on it' my car acts likes it's struggling to get through the powerband. Seems it's so rich, to the point of drowning. (not literally of course, you know what I mean) It's not hesitation, just seems to be getting overloaded with fuel, and bogs through the rpms.

Do you have a 'quick fix' or any suggestions that will hold me off until the 20th???? Help a brotha out!

PS: I already have your mail-in flash (only mod was the Typhoon intake)...I'm installing the mbc this weekend.

 

Call me - I can get you a temp flash to use till the 20th - OR just don't use it that much - your running too rich and w2ill foul the plugs

 

I am trying to understand why he is running too rich. I am going to install the walboro fuel pump before getting it flashed. I do not have an exhaust, but plan on installing the catback. Will the walboro fule pump hurt my car with only an intake? Should I hold off on installing the FP until the day before you flash it? If all goes well I will have the catback installed at that time.

Thanks Al!

 

Peters, good point...before I installed the fuel pump, the evo ran like a champ with the exhaust. For that reason alone, I was also contemplating waiting until the day of the custom tune to install the fuel pump...I should've followed my gut...it runs VERY poor right now...

 

Now you guys are scaring me. I am supposed to put one in before my session next month, but in reality, all I have is a catback, drop-in filter and flash. I can't see needing one yet. I don't think I am nowhere near maxing out the pump. I know the stock pump could be unreliable in heat and could drop output w/o you knowing it, but i may put a fuel press guage first to see if this happens, then do the pump or I wonder if I should put the pump in right before my tuning next month and Al can tune it in even with my few mods. That way I can eventually get my EBC and other mods and I am already set.

What do you think? Al, will you be mad if I don't change the pump? Can you still tune it fine or can I get more power with the pump and a better tune? I'm on the fence here. I don't want to foul my plugs and I don't plan to get crazy with mods.

 

people change the stock fuel pump out because it cannot hold a steady pressure through Hi RPMs. I would suggest changing the fuel pump.

 

Al I have your fireball 3 flash and about to put in my pump, I will not have this problem...right? Thanks for your help. Peace Scotty

 

If you change to a larger pump without any type of fuel control or tuning you have just made a big mistake!

Here is an easy way to think about it... The stock fuel pump at xxxx rpm supplies xxx amount of fuel. Your upgraded fuel pump (that is supposed to pump more fuel) at the same xxxx rpm now is suppling xxx+xx amount of fuel. So the end result is a car that is running very rich.

Hope I shed some light

 

This worries me. I am also about to do the swap.

I would have thought the ECU would sense the rich A/F and reduce the injector duty cycle.
Or does the ECU not get that feedback from the o2 sensors???

 

The ECU does not use O2 feedback during WOT. The feedback loop is shut off and the ECU uses set fuel maps.

My car does not run near as well as it did before the Walbro pump. I have a mail in Dynoflash and the car ran extremely well before the fuel pump. The O2 voltages went from .94 to .96 volts with the stock fuel pump. It went to 1.00 volts and occasionally a little over 1.00 volt after the fuel pump. Everyone who is running the Walbro pump needs either the dynoflash for the upgraded pump and/or an AFC or AFR. Al is working on this setup for the Walbro pump. Once he gets that dialed in, we will be running as strong as before. Until then, we will be running a little rich without using the AFC.

Brian

 

All my customers who change pumps can get the upgraded flashes for the new pump (when they are ready - in development - watch this forum for news on when the walbro pump tuned dyno flashes are ready)

IF you just change the pump - the car will run significantly richer in the high rpm ranges where it flows much more fuel than the stock one

Dyno Flashes that were set with the stock pump will run richer

How much richer you may ask??? At least HALF a point - so if your tune is going 11.0 then you will run 10.5 and etc

Is this dangerous ? NO - its going to be 100% safe. Will you loose a bit of power ? Yes - its going to fall down 5 - 10 whp and maybe more in some indvidual cases

Now what if you DON'T Change the pump - chances are you will be 100% fine

In 99.99 % of all cases it will keep making the same fuel psi and your tune will hold

However - both Vishnu and I have observed situations where the stock pump suddenly stops putting out the same psi

What happens is the flow falls down

This LEANS out the a/f'simmediately and suddenly

WHAT do you think is going to happen to your car this summer if your stock pump suddenly stops putting out enough fuel in the middle of a long pull in 4th gear on the highway ? Hint - you won't be happy !

BTW - we saw one STOCK evo in florida whoes fuel pump failed after we started re-tuning it and running higher boost than stock and more injector duty cycle

Please keep in mind when we updgrade your power - there is more fuel pressure with more boost (rising rate fuel pressure regulator) AND we usually run much higher injector duty cycles - which means on full gas high boost we are really stressing that stock pump

So what is my recomendation ?

On the one hand if you intsall the bigger pump you may run too rich and need a re-tune - worst case is it will be more rich - closer to stock in a/f although in most cases it will be still very good

On the other hand you risk having the stock pump fail and take out your engine

We have the following cars remaped with the bigger pump

Stock with K & N drop in
Stock with K & N drop in and Buchur muffler delete pipe
Stock with K & N drop in and Works Exhale

3" exhuast, K & N drop in and boost controller

If you have one of those cars we can give you a free upgrade

 

Thanks DAWG. You're always one to drop some useful knowledge.

As it turns out, I am getting tuned by Al.
But I am now bolting on a lot of mods - intake, exhaust, bc, cams, injectors, pump - and I have to
get the car to hold together for the 2 hr. drive to Pruven.
looks like I should bring a new set of plugs to change when I get there, cause mine may be fouled.

 

I think the conclusion is......put in all ur mods....including the fuel pump (safe measure)....injectors also prior to tuning....and it's not that hard.....just stay off high boost/high throttle till u get to the tuning session.....that's my plan and I have to drive from SD to LA for the tuning in socal. Just remember to not run ur car hard and drive as if a cop is behind u the whole time and ur fine. =)

 

Hi Guys,

I have one question about the fuel pump. Isn't the fuel regulator suppose to dump the excess fuel back to the tank? So is it true that even the upgrade fuel pump is increasing the fuel pressure on the fuel line, but the fuel rail will always see the same pressure because we are still using the same fuel pressure regulator? I am thinking about getting the pump too...so I would like to hear what you guys think.

Thx,
ob4

 

I was originally Flashed in October with an AEM intake and Buschur Muffler Delete pipe. I have since added a Hallman MBC and will be adding the Buschur 2.5" Downpipe and Walboro 255...I will be getting retuned the 20th at Agile...I guess my map with the fuel pump will be used for future people with the same mods?