need some feed back on aftermarket intank fuel pumps for a mildly modified 89 TPI setup. looking for a slightly higer volumn pump that drops right in place of the stock unit. mine stock unit with over 150,000 miles on it is starting to have a different hum as of late and want to replace it before it strands me in the middle of no where. any info is appreciated and I'm already aware of how much of a bitch it is so i want to make this as painless as possible. nothing can be as bad as a passenger side header install on these cars, i hope.

 

Everyone seems to be suggesting these:
http://members.home.com/syclone/APE/fuelpump.html

I plan on ordering one soon.


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Michael Graeber

My Garage

1)83 Z-28 T-Top: Full cage, 9" w/ lad.bars, Midwest Engine Tech 406sbc,Strip Dominator, Demon Carb, Phase VI Chevy Bowtie heads, .630" Crower roller set-up, 1 3/4 coated Hookers 3" true dual exhaust th400, fuel cell & still not running

2)89 Formula WS-6 305 TPI Auto For the road: minor motor, more suspension stuff. MODS

 

I recently intalled one of these walbro fuel pumps.......having trouble with it leaking down ...........NEXT time <shortly ...its gonna be a HOLLY replacment pump!!!!!! 87 GTA 350tpi,maf screens removed,K&N,ADSchip,3:73s,air intake modified,3inch cat back Flowmaster,TPS at.54,bosch plat plugs,accell cap&rotor,8 mm wires,base timming 6 BTDC,Bilstien schocks in the rear...by the way movin the MAT to the air intake just wasted gas,don't let yer meat loaf

 

I installed a Walbro 255ltr/hr pump that I purchased from the place in the internet address listed above (APE). No problems whatsoever. I, however, did remove the small device that sits in-line with the pump. Its some type of flow smoother ... or something like that. It looked way too flimsy and it looked like it could easily slip off the pump.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.587 @ 107.97mph (1.710 60ftr) on the long runner setup.
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels. Stock Wheels. No Weight Reduction.
Gunning for NA 11's with the MiniRam II and Hooker LT Headers.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

 

You must be talking about the pulsator- I tossed that too and just used high pressure rubber line in its place.

I have a Walbro 190ltr/hr unit, no problems with mine either.

I've also read somewhere you can use a pump from a GMC Syclone/Typhoon, but not sure...

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1989 IROC-Z, ZZ3 shortblock with some bolt-ons.
13.20 @ 108.69, 2.2 60' on "Road Hugger" radials and dead Auburn posi.

 

I've neglected fixing a fuel delivery bug I've had for a while.

Installed an afpr and new injetors a few hundred miles before this problem showed up.

Pump comes on and sounds normal. Fuel Pressure climbs to 43 PSI which is about where it was set. THe engine fires and runs normally but the pressure falls off at about 2-3 PSI/second until it quits running at around 10-15 psi. Pump runs the whole time. I clamped down on the return line and got the pressure to spike up to 60-70 psi. Haven't tried running it like that. May try that today being carefull not to let the pressure any higher than that.

I noticed some talk a nearby post about the stock pump being either 24 or 28 gph @ 50 psi. Mine is an auto parts store replacement for a 350 TPI so I'll assume 28. If I do the ole feed line into a jar flow test, should it flow similar to that rating or higher/lower?
The last fp I had worded fine and then just quit. A fuel pump that works but only half assed would seem a bit odd to me. That's why I'm leaning away from it being the pump.

I've heard about a "check valve" in the fuel pump, but I'm not sure why its possible malfunction would casue this problem.

Anyone ever have trouble with the diaphram or the spring assembly in the fpr? Again no leaks and everything worked fine for about 500 miles when I put it back together.

After a few tests I'm going to start by tearing down the fuel rail completely and replace every single o ring on the thing along with the diaphram.

Any comments would be appreciated.

 

sounds like your regulator is not holding pres......if you clamp the line going back to the tank you should get approx.75psi.this is with engine not running

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by the way i used a NEW pulsator when i replaced the pump....but it looked like a good seal on the line in and out.Now when i shut the car off the fuel pres leaks down quickly and if i block the main fuel line off it holds ...so its a problem in the tank..could be the pulsator<????could be the pump check<????? next time i hope GM put the fuel pump in a more suitable place..LIKE WHERE THE SUN DON"T SHINE

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87GTA,MAF screens removed,K&N,modified air intake,ADSchip,3:73s,3inch cat back Flowmaster,TPS.54,Bosch Plat plugs,base timing 6BTDC,Bilstiens all around....movin the MAT is a waste of time and GAS,don't let yer meat loaf

 

could be the check in the fuel pump....next time i hope GM put the pump in a more suitable place...like where the SUN DON'T SHINE

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87GTA,MAF screens removed,K&N,modified air intake,ADSchip,3:73s,3inch cat back Flowmaster,TPS.54,Bosch Plat plugs,base timing 6BTDC,Bilstiens all around....movin the MAT is a waste of time and GAS,don't let yer meat loaf

 

I use the Syclone fuel pump here, no problems at all for over a year now

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Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, MSD 6AL, Aluminum Driveshaft, TB Coolant Bypass, Ported Plenum, Modified MAF, Cyclone Fuel Pump, JET Airfoil

Veiw my car at: http://www.geocities.com/transam85tpi/TransAm.html

 

Like Traxion, I installed a 255LPH Walbro pump. I also dumped the pulsator..... No problems and now the pump dosen't go away on the top end

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Hank
87'IROC Z28
Hanks 87 IROC