Hey guys, I need to replace a section of my main fuel line and return line underneath my hood since they're very rusty, and the lines are only inches away from the manifolds.... a little nerve-wracking.

My question is how can I relieve the pressure before commencing? I have a 305 TPI engine. The manual said to just pull the "FP" fuse and kill the engine that way but there's no fuse labeled that.

I already had a bad experience with this, since I had to replace a section of fuel line going from the tank to the filter because of a tiny leak last summer. I actually lost well over a gallon of gas... not something that just a dirty old rag will absorb, like I've seen most people recommend. And yes I had my gas cap removed. And yes I've searched, but everybody's saying to just skip this step and just remove the lines.

Thanks!

 

That much gas shouldn't have spilled out unless the pump was pumping fuel. You can just undo the lines but do it very carefully and slowly. Pulling the fuel pump fuse and starting the car should use all fuel in the lines. This has worked for me with no issues before. As an added measure put the front of the car on an incline.

 

which fuse? i can't find one for the fuel pump. And I see your RS has a TBI engine, TPIs have higher fuel pressure from what I heard so that might explain why so much leaked out.

 

In my 89 tbi it is marked fp under the dash in the fuse block. I think it is a 15A Could yours be under the hood if not under the dash?

 

Hello musclecar70sfan!!

Which manual do you have??? My 1987 GM service manual for TPI says to connect a fuel pressure gauge (with bleed off hose) to the fuel pressure test valve, and then relieve the pressure that way, draining the fuel into a container, engine not running of course!!!



My suggestion is, get yourself the parts to make a bleed off hose, of the proper length, and then you can do it safely, any time that you want!!



Just to let you know, I tried the "remove the fuel pump fuse" thingy also years ago, my car just kept running, and running, and running!!!!

 

I have had the same issue with the fuel pump fuse,I have yet to find it. However I did find help on this forum a while back. There is a fuel pump connector @ the tank, which is pretty easy to locate, I just jack the car a bit and it's right there I believe @ the rear of the tank(maybe front) either way it's pretty easy to locate. Disconnect it and it's the same as pulling the fuse. try to turn over the engine to relieve any pressure and you should be good to go.

 

Hmm that sounds good. I think I might try that. Thanks!

I have a Haynes manual for 82-92 Pontiac Firebirds. I took a thin screwdriver yesterday and pressed down on that valve you mentioned. Some fuel squirted out, but not much, I was expecting more. I wonder if that's enough to depressurize the system.

But the easiest method seems to be to disconnect the fuel pump connector, assuming its not too hard to reach.

Although isn't there a fuel pump relay by the brake booster under the hood? Since I've heard about people disconnecting that thing to relieve the pressure. Which connector/wire/fuse is it? I see a bundle of stuff by the booster, I just need to know which one.

 

Hello musclecar70sfan!!

I'm not sure on your year/car, I have three of them at that location, and I'm not sure of mine either!!



On mine, I have a MAF Power Relay, MAF Burn Off Relay, and the Fuel Pump Relay!!

I also have a Van Nuys built 1987 305 TPI 5-speed Camaro Z-28, and it's not in the same order as my Norwood built 1987 305 TPI 5-speed IROC-Z Camaro either!!

I have to figure it out every time!!