12valve

So...
i put it all back on the truck, and i still have no success.

This time i adjusted the pressure for 33 psi with the pump running, engine off.
At idle it got down to 25 psi.
Reving it empty to 2000 rpm rapidly it drops to 16 psi
Flooring it on stock level on the edge, it drops to < 3 psi

i tried sucking directly form a 1 gallon bottle, and it didnt seem to change anything.
Could the engines return system return too much fuel? i dont "think" there is a restriction in the system, from the testing i did.

I put the return into a bucket, for testing and when the truck is ideling, the swagelock returns bunches of fuel. it fills a 1 gallon bucket in less then 5 mins.

could my pump be bad?

gotslicks

do you still have 2 regulator on it?

12valve

no, i ditched the holley like you said! and obviously got hard starting when warm again. my truck doesnt like over 19 psi for startup.

A holley style pump along with the stock pump works ok, on this truck, even on level 5, at WOT. the holley quit working a time ago, thats why i was looking into a more quiete pump and hopefully more durable.

gotslicks

wait wait you still got the stock pump on it wit this walbro?
your blowing/pulling thru the stocker?

12valve

nop... lke this: tank -walbro - regulator - fuel filter - vp44.
i bypassed the stock pump.

sheriffav8r

If the Swagelok is returning tons of fuel your fuel pump is working. The pump is pushing fuel at whatever pressure no matter what. At this point I might try to take off the Swagelok and just run pump to VP and see what your pressure is before you start the engine. If it's not too horribly high, start your truck and try looking at the pressures while driving. If you still drop too low you then probably have a pump problem. I can't for the life of me figure out why you would have 33psi off, 25psi at idle, and drop so low at WOT, unless your truck is sucking up tremendous amounts of fuel.... Do you have 3/8" lines all the way to the VP? Your hard start issue would go away if you hook your Walbro up to the OEM wiring harness (even put a relay in there if you want). Then it wouldn't be running when you start the truck. Take off the Swagelok and get a head pressure reading from the Walbro and let us know, just don't blow your FF top off....

gotslicks

i had the same problem at first now that ive thought about it.
i had 2 problems
1 as that the fittings for the big line kit broke so i got new ones for hydros....the holes in the fittings were super small so i had to drill em out to make em flow.
also i had my line between the filter and vp twisted and it was kinking the line.

where did you get the fittings from......what size lines u using? look at the diameter of the holes not the diameter of the fitting. youll probably have to drill em to 3/8 or bigger.


ill bet the fitting goin into your vp has a small small hole.
also
how is your fp gauge td into the line? what size r those fittings?.

gotslicks

you say it rapidly drops to 16 or 5 at times.
will it recover if you keep you foot in it?
something is fishy!

12valve

Thanks! I could try that, im affraid of blowing the diafragm in the vp pump!
I have been running of the stock OEm wiring harness to power the pump.
THe fp doesnt recover, unless i let off the throttle!

Its stock hard fuel line from tank to the walbro, then its 3/8" hose to the walbro and to the regulator, from there its the same size hose to a stock cut off oem hard fuel line with banjo bolt into the filter, from the filter to vp it all stock. i should be upgrading to bigger lines from filter to vp, but i still dont get why it works with a holley/stock pump. that setup pulls to down to 4 psi everything on kill. and 19 psi idle

gotslicks

where are you picking up pressure for your gauge

12valve

on the top of the fuel filter canister on the banjo that goes to the vp44