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Discussion Starter #1
Hi guys, fitted a walbro fuel pump yesterday and several of the UK forum guys are bleating on that I should get it retuned because it will run far too rich? Surely the fuel pressure regulator and the ecu control the fuelling and not the fuel pump..........Any thoughts?
 

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I would check the fuel pressure as well as check the AFR's. I agree that it create a rich issue.
 

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I don't think it would cause any issues. The regulation is still controlled by the fuel injector duty cycles.
 

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I don't think it would cause any issues. The regulation is still controlled by the fuel injector duty cycles.
Regulation is controlled by a fuel pressure regulator. If a new pump increases the base fuel pressure then the injectors will flow more when they open at a given IPW. So IF this new pump increases the BFP then it will cause a rich condition throughout the RPM / Load range.
 

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Why would the base pressure change if the stock regulator is still installed?
Because a stock FPR can only handle so much flow...changing out a fuel pump to one that flows more than the stock pump can cause a increase in base pressure.
 

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Discussion Starter #8
So, rich is safe right? Should be ok for a couple of weeks until I can get to my tuner? Only thing I notice is a couple of times starting from warm/hot not as quick as before.........
 

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So, rich is safe right? Should be ok for a couple of weeks until I can get to my tuner? Only thing I notice is a couple of times starting from warm/hot not as quick as before.........
too rich can be just as bad as too lean
 

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Discussion Starter #10
Update:
Took car to tuner to get mixture checked and tune Forge adjustable BOV at the same time..... With valve set to hold about 2psi more boost, the afr's get lean at the top end as in 13/1... The injector duty cycles are maxed out and the tuner says I need a: bigger injectors, b: fuel regulator, c: fuel pump (Walbro) is faulty (Unlikely)
Help!
 

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If the injectors are maxxed out then you need new injectors if you already have an upgraded fuel pump.

If you can post up a datalog of what is going on that would help us help you

You shouldn't need a new fuel pressure regulator unless your planning on running over 700 whp
 

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Discussion Starter #12
Sorry, don't have any logs from today, he just plugged in and we went for a blast up the road to check it.... Very mixed opinion over here, some say around 320whp is the max for std injectors, others say at this level there's no need for an uprated fuel system..... What do I do, drop $500 on some I D or similar injectors and see if that fixes it or do I look elsewhere? :wallbash:
 

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Discussion Starter #13
Problem is we just don't have the depth of tuners over here that you guys do, we've only really been tuning this year because of warranty issues, I'm past that , I'm a big boy now, if it screws up I'll just have to sort it! A sentiment not held by many here, they've all been waiting until the 3 year warranty is up, hence the 3 year delay.........
 
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