Fuel Pressure bleeding off

**spdecar** · 04-05-2014, 02:19 PM

2002 Trans Am LS1. It starts fine when cold or even after sitting for a few minutes. However, if you let it sit, say 10 minutes and try to start it, it cranks for at least 5 seconds before starting. Or if I stop cranking and hit it again it will usually start then. I checked the fuel pressure at the rail. When I turn the key on (not starting) the pressure goes up to about 50 and then starts dropping. I can hear a click in the relay when the pressure stops dropping but I switched the relay with the AC and it still does it. Once the car starts, it holds a constant 58 lbs pressure. Any help would be appreciated.

***SMWS6TA*** · 04-05-2014, 04:53 PM

Hate to break it to you but you're going to need to drop the fuel tank. The plastic fuel line on the regulator has a crack in it. Simple fix just a pain to get to.

**spdecar** · 04-06-2014, 07:26 AM

I was afraid of that. So the fuel pump and regulator shouldn't need replaced? Just the fuel line?

***SMWS6TA*** · 04-06-2014, 10:29 AM

there's a plastic pick up tube that is part of it. most likely it has a crack and that is why you have bleed off.

this flex tube is what I'm talking about like in this pic

**spdecar** · 04-06-2014, 11:35 AM

Thanks for the picture. I see what you are talking about. What brand replacement pump would you recommend? After some research I was just about set on a treperformance pump. Is the racetronix a better pump? I sure don't want to do this twice! The motor is stock other than performance tuning on the computer.

***SMWS6TA*** · 04-06-2014, 01:52 PM

you should be just able to fix the tube. If a pump replacement is needed then the Racetronix is about the simplest & best buy.

**spdecar** · 04-06-2014, 03:51 PM

Thanks for your help!

**pajeff02** · 04-06-2014, 04:21 PM

Possibility it is a pump issue too. Our Suburban acted about the same way and over time it just got worse. Pump is getting swapped in our Trans Am soon, it bleeds off pressure as well.

**spdecar** · 04-07-2014, 08:25 AM

Thanks. I may go ahead and swap the pump while I'm in there, just in case.

**pajeff02** · 04-07-2014, 08:26 AM

Racetronix makes a nice unit but their customer service leaves something to be desired. I would order it through a third party vendor if you go that way. Our site sponsor, Granatelli, has a direct fit Walbro fuel pump for our cars.

**spdecar** · 04-07-2014, 08:39 AM

Would you recommend the Walbro or the Treperfomance pump From my research the Treperfomance is quieter and has a one year warranty. It's also about $30.00 cheaper, which seems odd if is a better pump.

***SMWS6TA*** · 04-07-2014, 09:09 AM

IIRC Racetronix uses Walbro pumps.

**pajeff02** · 04-07-2014, 05:16 PM

I have never heard of "Treperformance". Walbro is what most members run and that does include the Racetronix setup.

**spdecar** · 04-21-2014, 01:30 PM

One last question. I've got the tank off, new pump and hose installed on the assembly. I see there is a regulator on the assembly. Could this problem in any way be related to the regulator? I hate to put this thing back together and it still not be fixed. Problem is the regulator's only come with the whole assembly which is over $300.00. The car is at my Buddy's shop as has to move tomorrow!

**pajeff02** · 04-21-2014, 04:50 PM

Not likely. New pump should take care of the issue.

**spdecar** · 04-21-2014, 05:39 PM

Thanks for the help on this! Gonna put it back together.

**0rion** · 04-21-2014, 07:27 PM

in theory it could be the regulator....did you inspect the accordion style hose? Did it have a crack in it anywhere?

**pajeff02** · 04-22-2014, 02:14 AM

It would be simple to check - just raise the tank into position, plug everything in, and then energize the ignition with a gauge plumbed to the rail. From what the OP described, it sounds exactly like what we experienced with our Suburban - extended cranking to start and fuel pressure that bled off quickly.

**spdecar** · 04-22-2014, 04:13 AM

We may do that. Thanks.

**Firebirdjones** · 04-22-2014, 05:01 AM

Keep in mind, the racetronix pictured above is the only pump for the 2000-2002 Fbodies I found that has that necessary tiny brass nipple (see picture above)
That is for the hose that keeps the bucket full of fuel the pump is encased in. Only other way I found to aquire a pump with this fitting was to purchase the entire bucket/sending unit stock setup that runs $3-$400 as you found. Without this setup the pump will run hot as the fuel level drops. Some people think that cutting the bottom of the bucket open is the answer. Not a good idea, the bucket will only stay as full as the gas tank itself.

If you decide to go with Treperformance (never heard of them) make sure it has this small nipple for the hose connection. If not, I'd look elsewhere, and recommend the Racetronix setup personally.