New WP307 = 1 gallon in 1m 45sec-WTF!!

[TClassic2]

Guys,

As the title says, while tranfering my race gas I timed it, a Hot Wired
6 month old 307 pump takes ALMOST 2 minutes per gallon! Whats up with
that? My old car had a HW'ed 340 that, although I didn't time it, I knew it was
OK as it came out like a FIRE HOSE! I I nstalled this one the same way,
cutting the burr off of the metal part of the fuel line, & checking the rubber parts for any knicks, new delco filter!
I'm only running Mid 12's at 109 for now, and my O2 numbers are OK -
759-770 - on the top of 3rd with 20 Lbs of boost & good gas - But the
minute I upgrade - FERGET IT!

Now I realize I should throw a 340 at it, but is there any way to Bench test
this SOB while I have the tank down?

 

[Addicted2boost]

I know this may sound stupid, but did you have the gas cap off the tank at the time when you were draining? Other than that, any other electrical things on, like key on, radio and or hotwired radiator fan on? 1 gallon in 2 minutes sounds ok to me. That's the FP that I use. Plus it will put out alot more when the car is actually running and putting out 2 more volts to the pump. Gotta think about that.

 

[TurboDave]

Same hose size? Same fuel rail fitting? Same everything?

 

[GNandGS]

"T" fitting?

 

[TClassic2]

Guys,

Yes, Key OFF, Just the fuel pump prime connector & the Alternator
HOT post, Same size hose - always! Just for information purposes - This test - A GALLON in 60 sec or less is the expected norm (for a HEALTHY fuel pump in a TR that is)!

So either the pump is BAD (most likely), or this low mileage car has electrical gremlins (remote)! It just pisses me off!

 

[Steve Wood]

Put a meter on the hot terminal and see if you have full voltage....(whatever the battery reads)......be sure it is well grounded.

 

[TClassic2]

Dam, never thought of THAT! This guy did, un-neccessaryily, replace the Alternator, could he have gotten the Wrong one (amerage -wise)?
Steve, you MAY be onto something, Thanks!!!!

 

[Eds87GN]

Try loosening the straps that hold the tank up and see if it does better. Might be a kinked hose above the tank.

Later,
Ed

 

[DR BOOST]

replace ur fuel filter.

surej

 

[BobbyBuick]

is the core in the fuel rail ? schrader might not be working .remove the core and time it

 

[TClassic]

Bobby, good suggestion, although I have the Snap-On hose
with the Thing that pushes in the Schrader Valve.

Dr Boost & Ed, I just put a New delco filter in there (it passed the
Blow Through test). And I also slightly dropped the tank, unfortanitly the lines are PERFECT (no kinks!).

What reading, exactly, shoud I get on the Alternator post with
a digital Volt meter?

 

[ijames]

If the motor is not running and the only current going through the wire from the battery + to the back of the alt where I assume you are picking up the power for the fuel pump is the pump power, you should read within less than 0.05 V difference between the + and - terminals on the battery and between the alt post and the alt bracket (dig the lead in for a good connection). With the engine running and everything turned on high to load the alt as much as possible you should see less than 0.2 V difference between alt post and battery +, and much less than that between alt bracket and battery -. With the motor off and the pump running to circulate fuel back to the tank, compare the previous alt post/alt bracket reading with the voltage between the pump hot wire and ground back as close to the pump as you can get (probably that connector by the bumper?). You should see less than maybe 0.1-.2 V difference by going through the pump power and ground wires. If the voltages look good, maybe try pulling the filter and measuring the delivery volume back there to make sure nothing's wrong with the feed line?

 

[TClassic]

Carl,

Excellent Points!! I'm DETERMINED to get to the accepted TR
Norm of 1 gallon in 60sec. or less!

Interestingly though, my O2 numbers, now that I upgraded my Stock injectors, have gotten MUCH better on the Top end, Now 755-770 at the top of 3rd (20Lbs of boost) as opposed to 699-700even, before, hmmm................

 

[Nick Micale]

There is another possibility, the 307 may be bad!

This is my "least favorite" pump as I have seen MANY of them either go completely dead, or almost, in short order. I will not install one in and car intending to be run at WOT more than once.

 

[TClassic]

Originally posted by Nick Micale
There is another possibility, the 307 may be bad!

This is my "least favorite" pump as I have seen MANY of them either go completely dead, or almost, in short order. I will not install one in and car intending to be run at WOT more than once.

You know, I kind of think the same thing, although when I ordered a Pump for this car from Cotton's i ASSUMED he was going to send me the Accepted Standard, the Walbro 340, but I got the 307 instead. I called him right away, and he explained,
and I subsequently found out myself after calling Precision,
Kirbans, Connelly's, ect. that they ALL SEND OUT 307's!!! And Precision, at the time Mr. Lubrant, assurred me that it would be TOTTALLY un-necesary for me to wait & swap the 307 out for a 340, and I'd bet that a lot of guys, Newbe's Especially, just go ahead and install these (307) pumps they get from the Vendors, again ASSUMING thier good (after all thats what the Vendor sent them) without even looking at the pump! Or checking it afterward, other than looking at thier O2 numbers!

 

[turbolc2]

307 Flow Data

Someone (maybe I can find the data sheet) on this board had done some testing with a 340 vs a shimmed 307.The shimmed 307 won out.Mike Licht clearly stated that a 340 was a 307 with a higher pressure "pop off" valve spring.Cotton claimed he had made numerous mid to high 10 sec passes on 1 307.Of course a hot wire & properly prepared plumbing must be in place.Maybe even a volt booster.Are people telling whoppers?

 

[TClassic]

I do know that Jack "DID" go 10's on numerous occasions with
1 307, and Mike Licht also told me that they ship 307's when a customer calls and doesn't neccessarily specify a "340".

Oh well, back to the original topic, I think I better just go ahead and start checking voltages and such like I planned, FIRST, before I blame the pump. And also, how do I do a simple becnch check once I pull it out??