High Volume Fuel Pump

[KnappAttack]

Be easy for you to find out with your adjustable FPR.
Makes me wonder just what all goes into creating a closed-loop map? What is target AFR? What else do they factor in? What muffler? What air intake? At what IAT, what coolant temp, what humidity, what barometric pressure, what boost, etc?

Closed loop in the ECU just targets a specified A/F ratio, you can alter any of those items like mufflers and intakes and it will hit the A/F asked for as long as the base maps are somewhat close, it will add or remove fuel from the base map accordingly. You can see it on the logs where the ECU is adding or removing fuel from the base map with the percentages. I believe it's only available with the GAP platform, so only Hurricane and TD. I dont think PEFI has this feature.

You can alter the wide open, cruising and mid cruising A/F ratio and the closed loop and hit those figures as long as certain things are met like a speed threshold upon where closed loop activates.

 

[fatchance]

Guys i seriously think this is a more simple fix than what it appears. I think Glenn’s symptoms are very similar to mine. Bob i though the same.... Crank up the fuel pressure to overcome the inefficiency. Didn't work.
So as i said before i thought maybe the chintzy connector at the fuel pump was the cause. So today i wrapped a zip tie around it and the sled ran flawlessly for 150 miles.
Then it was a rip down the lake wide open at times for a half mile several times until i let off at the bottom of the lake and it came to a stall. I sat and let the sled idle for at least 5 minutes and beat on it for the last 20 miles on the way back to the cabin and again it worked flawlessly.
Got back after dark so i could look, but my money is on a kinked tank vent line.

 

[Fords4life]

That pump is 415LPH? Who's tune are you running?

My bad grabbed the wrong box, that pump # was for my 07 mustang gt, this Deatschwerks # is what i used with 300hp header tune #9-201-1000

 

[Fords4life]

You actually see any crap wash out when u clean them?

Yes every time, the filter will also gain a lighter clean look to it.

 

[jonlafon1]

One thing that's probably not related but you never know. When running LEADED race gas mix,(mostly after) my AFR sensor will clog and become very lazy and has to be replaced. It will read but you can tell its not reading as should be. And I know for a fact as I replaced it with a new one and it acts as it should.(way faster in changing number while throttling through) This is NOT closed loop//it is with a KOSO stand alone afr. No more leaded race gas mixing for me anymore. Im going with unleaded race gas as its plenty of octane anyways. My point here is, if your running any leaded fuel does this coat/clog or cause your afr sensor to run incorrectly and then cause issues with closed loop fueling? Like over or under fueling? Guessing you will see it in the logs.

EDIT

 

[Turboflash]

Closed loop in the ECU just targets a specified A/F ratio, you can alter any of those items like mufflers and intakes and it will hit the A/F asked for as long as the base maps are somewhat close, it will add or remove fuel from the base map accordingly. You can see it on the logs where the ECU is adding or removing fuel from the base map with the percentages. I believe it's only available with the GAP platform, so only Hurricane and TD. I dont think PEFI has this feature.

You can alter the wide open, cruising and mid cruising A/F ratio and the closed loop and hit those figures as long as certain things are met like a speed threshold upon where closed loop activates.

Just FYI - just in time for the the sunset of the 998 era (maybe?) PEFI told me they will have their own closed-loop for 998 next season. Why it has taken them so many years of the 998 to do that IDK?

 

[DooZ]

Gap selling some of the tech on a sunsetting era to make the last bit of coin? Or...PEFI just getting around to st------ it lol

 

[KnappAttack]

One thing that's probably not related but you never know. When running LEADED race gas mix,(mostly after) my AFR sensor will clog and become very lazy and has to be replaced. It will read but you can tell its not reading as should be. And I know for a fact as I replaced it with a new one and it acts as it should.(way faster in changing number while throttling through) This is NOT closed loop//it is with a KOSO stand alone afr. No more leaded race gas mixing for me anymore. Im going with unleaded race gas as its plenty of octane anyways. My point here is, if your running any leaded fuel does this coat/clog or cause your afr sensor to run incorrectly and then cause issues with closed loop fueling? Like over or under fueling? Guessing you will see it in the logs.

EDIT

Jon,
Boostane octane booster works wonders if you need more octane. Best I have found to date. Use the Professional version and you use very little of the stuff unlike the other boosters on the market that don't work at all or need a massive dosage & costs associated also.

 

[jonlafon1]

Jon,
Boostane octane booster works wonders if you need more octane. Best I have found to date. Use the Professional version and you use very little of the stuff unlike the other boosters on the market that don't work at all or need a massive dosage & costs associated also.

For sure. I got some of this. I caution guys mixing LEADED race gas in if you want accurate AFR readings.

 

[Turboflash]

Fuel pump size?
Stock injectors are 485 cc/min.
There are 3 so 1455 cc/min @ 80% duty cycle at 43.5 psi fuel pressure.
1455 cc/min = 87.3 liters per hour.
So even the little Walbro 155 lph is almost double in size to what stock injectors can flow at wot.
BTW - w 20lbs of boost, fp goes up to 63.5 psi. Even at that pressure, flow rate is about 126 lph; still less than the 155 lph pump will flow. And, that 63.5 psi is only there as long as boost is at 20.

 

[sideshowBob]

Just FYI - just in time for the the sunset of the 998 era (maybe?) PEFI told me they will have their own closed-loop for 998 next season. Why it has taken them so many years of the 998 to do that IDK?

That is definitely late to the show!

 

[Doc Harley]

This topic hits home as i am running a gss342 off Amazon. ($75)
Hate to have to do a "parking lot pump swap " in some random parking lot.
Walbro is very strong in the automotive community. My hopes are they've seen the warranty issues and made correction. Or perhaps the return issues are very limited, in terms of the big picture.
The internet has a way of making a mountain out of a mole hill.

 

[jonlafon1]

I think guys are getting fakes.

 

[Doc Harley]

I think guys are getting fakes.

I think fatchance has gotten two directly from walbro. However, I could be mistaken.

 

[jonlafon1]

I think fatchance has gotten two directly from walbro. However, I could be mistaken.

Could be? I just know I would only buy direct from them(walbro). Or another brand by fords4life mentioned. Deatschwerks . Pretty reputable company. I run a inline fuel filter from them on another sled. I have no experience with the pumps they sell but its a sold choice IMO.