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wilkink 10-01-2008 07:22 PM

Gas Leak
Well, I caught a strong smell of gas which I took quick notice to. I found out what the problem is but I dont know the part number. The fuel hose severed that goes from the pressure regulator to what seems to be the lower part of the plenum. Its about a six inch hose. It has a rubber slide the side of the plenum. If anyone could get me that part number it would be great. I'll be checking in many a times tonight if you have any extra questions in determing which hose it is.

Thanks in advance,

wilkink 10-01-2008 07:29 PM

Re: Gas Leak
Also, since I cant get the part tonight, what would be the recommended cheap fix for the night to stop the gas from trickling? Thanks again.

FearThisGTA 10-01-2008 08:28 PM

Re: Gas Leak
Uuuummm thats a vac line. If it has gas comin from it that more that likely your reg diaphram is leaking.hth

wilkink 10-01-2008 08:38 PM

Re: Gas Leak
Alright. I have a Chilton manual and I cant find a model of the fuel pressure regulator. I have no clue what the diaphram is. I could have sworn the gas was leaking from the hose. But, is there a way to tighten it or do I have to buy a new one?

FearThisGTA 10-01-2008 08:51 PM

Re: Gas Leak
Just go to your lacal parts store and tell them what you need. As for what a diaphram is its the piece in the middle of the reg that depending on adj will set your Its round and has appears to be 2 nickels clamped together. hth

wilkink 10-01-2008 10:04 PM

Re: Gas Leak
Sounds good. Is there any way to fix it tonight without the part. Just for a day or two untill i get it.

FearThisGTA 10-02-2008 04:58 AM

Re: Gas Leak
Hmmm, not that I know of. You could probably relieve the pressure by pressing in the shraeder valve and it will probably bleed down like so and that should stop it.

wilkink 10-02-2008 10:56 AM

Re: Gas Leak
Alright. Looks like I'm going to just buy a new one and install it. I have been looking through a good amount of threads and I see that you recommend the Holley one. It is like a AFPR or something like that. By any chance do you have the part number on it? I have been looking for it and I cant find the thing anywhere. Also, how hard is it to install one of these things? Do I need to buy gaskets for the plenum and runners since it looks like I have to take the plenum off? And is there anything else I should know about before I start doing this? Thanks again Cliff.

merc3065 10-02-2008 02:10 PM

Re: Gas Leak
Just go to your parts store and ask for a TPI Adjustable Fuel Pressure Regulator made by Holley.

You should consider replacing the gaskets on the plenum when you pop the runners and plenum off to replace the fuel pressure regulator.

The only other thing I would recommend is when you have it all off, is to make sure you either tape the holes on the intake manifold, or keep it covered with cloth.

You will need a T10 or T7 security torx bit to remove the screws from the plenum. You will need to reuse these. Do not lose these or over torque them. I can't find replacements for them anywhere so I doubt you'll have an easy time finding them. They are really fine machine screws so dont break em.

Label which torx bolts go where in the runners/plenum.

And if something looks like its attached to the plenum, it probably is so be careful about any hard vac lines or other wires that are attached.

wilkink 10-02-2008 02:23 PM

Re: Gas Leak
I've been looking online and on each site there is a different Holley that fits my car. I was on AutoZone and it seems like they have a diaphram fix for the leak problem. Maybe I could use that until I get the Holley.

merc3065 10-02-2008 02:31 PM

Re: Gas Leak
yup you can. You can use the holley diaphragm as well to repair your stocker. But yeah, diaphragm as long as it fits, install it and off ya go

This is the holley one off of summit...

Holley AFPR for 86-92 TPI

wilkink 10-02-2008 03:44 PM

Re: Gas Leak
Thanks. Just wondering if there is a difference between the 305, and the 350 when it comes to these things. I have a 350 and it looks like this one is for a 305. But if not, I'll order this one tonight. Also, where would you recommend buying the gaskets for the runners and plenum. I'm going to look on summit now and see what I can find on that.

wilkink 10-02-2008 04:53 PM

Re: Gas Leak
Just wondering if these are the gaskets that would be needed for this installation. Gaskets. Do I need any other gaskets?

FearThisGTA 10-02-2008 06:23 PM

Re: Gas Leak
That should get'er done.

wilkink 10-02-2008 06:30 PM

Re: Gas Leak
Cliff, hopefully your still on. You know if that FPR will fit a 5.7? It is listed for a 5.0.

merc3065 10-02-2008 07:01 PM

Re: Gas Leak
Yep, its for both.

The fuel rail was designed for the TPI system, not the motor that the TPI is sitting on top of. Gotta remember, the only major differences in the intake for the 305 and 350 is the injector size and whether or not the intake had EGR passages (in the case of the vette which had external EGR).

wilkink 10-02-2008 07:05 PM

Re: Gas Leak
Alright thanks man. One last question here. How do I set the psi after I install it? Should I order a fuel pressure gauge or is there something else that I need.

merc3065 10-02-2008 07:13 PM

Re: Gas Leak
Fuel pressure gauge would do the trick.

If you have loan-a-tool programs where you live see if they have one that you can borrow. I cant remember the cost when I bought it...

Theres a shrader valve on the pass side fuel rail that the gauge screws onto.
Make sure the pressure in the fuel rails is bled off or you will be eating a spray of gasoline when you pop the gauge into the rail...
I make sure that I stuff a shop towel or paper towel in and around the valve when im hooking the gauge up. It prevents any left over fuel from getting anywhere it's not supposed to be.

Turn on the car after everything is all back together.
Then, pull the vac line off the regulator. Don't worry so much about the vac leak as its only temporary...

Then, start adjusting the knob up or down until you hit 42PSI, I usually run 44-48 with my best results. Gives it just that little bit more of power in the upper RPMs.

Once you're done, put the vac line on and shut the car off.
There should be a bleeder button on the gauge to bleed off the pressure. Disconnect and put the valve cap back on and off you go.

Note: the best way i've found to bleed off the fuel pressure in the rails is to pull the fuel pump fuse up by the battery.

OR, leave it sit over night.

wilkink 10-02-2008 07:26 PM

Re: Gas Leak
Thanks. Thats almost exactly what I needed. But, I saw a few fuel pressure gauges that stay on the car. If I were to buy one I would like to have one of them. I'm looking to spend up to about 20 dollars on that. Which gauge would be at? I'm guessing it will probably be on summit. Thanks alot for that last post.

wilkink 10-02-2008 07:33 PM

Re: Gas Leak
This one be good? Summit.

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