Does anyone know who sells a fuel pressure gauge for a decent price? I've heard $40 to $50 bucks for testing purposes with 10lb incraments. I would like one with 1lb incraments so I can tell exactly what I've got. Inline gauge or tee for testing. Advance says I need one rated at 60lbs for my Lo3 Why? If it only runs 9-13 lbs would I need that? Any help is appreciated as I would like to get this SOB running right this weekend. Thanks

 

Auto Zone sells a tbi fp test kit for $40. It reads to 60psi in 1psi increments. Go with one that reads 60psi, you never know, you may change fuel pumps one day, do a lot of modding, and need the extra fp

 

Thanks for the info! I'll check it out. Seems a shame to spend $40.00 bucks to find out my $43.00 fuel pump is bad huh?

 

The wife bought me a FP tester today, said she got tired of me crying about my car not running right! guess what? damn thing is only putting out 7 1/2 lbs pressure! even with the return line pinched off. Soooo, further updates after the new pump install next week-end! Auto zone tester cost $42.00 after tax.

 

Now is the time to go with a better pump! Don't go with a stock one especially if you have plans for furure mods.

 

Get a Walbro 255!

 

Decided to go with weber brand sold at Napa! I cheated and used my angle grinder and cut access hole through floor pan, the whole job only took 2 1/2 hrs. Damn car runs better now than when I bought it! 13 1/2 lbs at Idle. Total price was 64.00 for pump, strainer, fuel hose, and clamps. I want to thank all that helped me with this problem. This web site has been a BIG help to me and I hope to return the favor to all I can. I missed most of the auto-cross season this year (blew radiator in first one, Tires, Bad weather, and then fuel pump) BUT, I'll post pic of trophy next spring!!:hail: BTW Vader, the pump kit came with a new section of hose. Isolator, clamps and all for $43.00

 

SQZbox

could you take a picture of the hole you made and maybe some measurements if i can get to the fuel pump to put in a 255 walbro with out taking the rear end off im going to stick with tbi instead.

 

For some reason, everybody seems to think you have to drop the rear end. But you DO NOT NEED TO DROP THE REAR END! The trick is to place the jack stands so the rear end "hangs". Dropping the fuel tank is not that hard really. The only "difficult" thing about it is removing the exhaust. If your cat hasn't welded itself to the rest of the piping, then even that is not that difficult. Depending on the environment your car has been run in, some of the lines and bracket bolts can be a pain, but once again not that big of deal. And of course it is ideal to have the least amount of gas possible in the tank.

 

Removing the exhaust isn't hard if you remove the rear right tire and unbolt your panhard bar. Then unbolt the cat with 2 bolts and slip the whole system out as one piece. It's really easy this way, don't know why people don't do it.

 

because if you are like me it took a torch and sledge hammer to get the exhaust loose. rust sucks...

btw, ive never replaced the fuel pump though. If I did. I would never cut a hole in a perfectly good peice of metal. I would rather remove bolts. But then.. I have access to lifts and air tools. To each their own.

Its like breast implants... sure there are benefits to that route, but do you want the scars?

 

:nono: What's the damage if you can hide the scars
Seriously, I agree dropping the tank is the way to go, if not for safety concerns at the least.

I hear ya on the exhaust too, i eventually just cut the darn pipe and welded it back together when I was done...no worries about messing up the flow though, the cutout is a ways before the weld

 

That gauge in the kit, do you leave it on or just attach it when you want to do some tunning?

Also can anyone here tell me the difference between a vafpr and a afpr is? I know the vafpr is vaccum...? How does that work?

thanks

 

Well, I leave mine on, though I do not recommend it because of the type of gauge it is. I have my fp set to 22.5 psi, and have the chips burned using the pressure as a constant. I guess the reason why I leave it connected is because there is something going wrong with my car all the time, and usually checking fuel pressure is part of troubleshooting. But like I said, It is safer and easy to only connect it when you need it.
A standard afpr is adjustable obviously, but will remain at that pressure no matter what rpm or load you're at (given the pump can handle it).
A vacuum referenced regulator uses a vacuum line to vary the fuel pressure. At idle, there is less pressure because of less vacuum. At wide open throttle, or any thing off idle, vacuum increases thus increasing the fuel pressure as well. For pure example only (figures are only to give an idea and do not represent actual values) fuel pressure would look like this with a vafpr:
idle at 700rpm: 9psi
1/4 throttle at 1,500rpm: 11psi
WOT at 4,000rpm: 15psi

A vafpr is good for high fuel pressure applications, as high pressures at idle can make for a poor idle.

 

Thanks!
So there is only a need for one of them?
Are both pretty basic? Or one a little more complicated then the other?

 

#1: speed, It took me 2 1/2 hrs. from the time I unlocked the hatch till I started it and checked the FP. I drive a semi during the week and I didn't want to spend my week-end messin' with the car. Messin' with the wife is more to my liking!
#2: Metal is replaceable, got a piece of 16 Ga. and put it over the hole W/4 screws and you cant even tell (under the carpet). I used a broken bit so I wouldn't stick the tank.
#3: safety you say? Not One drop of fuel hit the floor next to my fire extiguisher.
#4: I guess the moron in me said "I can do this a different way" !
You know, I wish I had a dig. camera so I could have docu. this job. The only help I can give on the location is, It's dead center of the hump. I tried to explain as best I could where to cut in previous post that's all I can do from here! As far as leaving the FPTG IN-LINE, I thought about it and concidered leaving the adapter IN-LINE but when I looked through it before I put it in it looked smaller than the fuel line and I didn't want anything holding up the fuel. (like it would really make a diff. on my wimpy 305 right?)
:lala:

 

i know this is old but i have been referencing old post about fuel pressure.
at idle vacuum is highest. at wide open throttle vacuum is near zero.
with vacuum the reg is lower.