Chevy Impala SS Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
426 Posts
Discussion Starter #1
I have a very little used '96 DCM. I have only about 61,400 miles on it. I was going down the highway a few days ago at about 70 MPH and I thought that I smelled gas coming through the vents while the A/C was on. After a little more driving, the smell went away so I thought that I must have been behind someone else that was "leaking".

The next day, I went into the garage and I could smell gas. That isn't normal or typical for my garage so I looked under the car and along the driver's side rear section of the frame to see if I saw any stains or dripping. Nothing. The floor of the garage is totally dry.

Since I smelled gas inside the car while driving, I ordered a new Delphi fuel pressure regulator and a new AC Delco fuel filter. They aren't supposed to arrive until July 3.

After 24 years but only 61K miles, the only other things that I can thing of would be the charcoal vapor canister or one of the fuel lines near the vapor canister.

Any thoughts or recommendations are most welcome.
 

·
Registered
Joined
·
1,216 Posts
I will not he surprised if you still have the same smell after replacing FPR and fuel filter. You have not seen the actual leak from FPR right? A leaky fuel filter would leak for a while after shutting engine off. You should try and find the leak before ordering new parts.
 

·
Registered
Joined
·
426 Posts
Discussion Starter #3
The FPR arrived early - today actually. I don't have the replacement fuel filter yet. The fuel filter is a typical maintenance item that won't go to waste. I did not remove "home plate" yet to feel around the FPR to see if it's damp.
I have the day off on Friday so that is when I planned to tackle this. In order to work on the car, I have to pull it out of the garage. I would assume that powering up the fuel pump will make fuel leak from somewhere or push more fumes out of a ruptured line.

I resisted ordering a replacement charcoal canister because they cost over $100 these days. I miss the early days of the Impala SS Forum when members got a discount from Dal Slabaugh and the GM dealership where he worked in Akron, OH.
 

·
Registered
Joined
·
11,239 Posts
Chances are that the FPR is the issue. You would not smell fuel inside the car if it was the filter. Check the lines to the canister, and all the way back to the tank. The lines are 25 years old and are noted for deteriorating.
 

·
Registered
Joined
·
426 Posts
Discussion Starter #5
Thanks Fred. The filter was purchased simply because if I'm going to mess with any of the fuel lines, I'm replacing the filter. I have to double check my maintenance file but I'm pretty sure that the filter was last replaced about 20,000 miles ago which means it was replaced about 2010.

The car has never seen snow, very little rain, and has had 24 years of Ziebart undercoating treatments every October before it gets stored for the winter, so if the fuel lines are bad, I would suspect the rubber tubing at the top of the tank or at the charcoal canister. Also consdering that I don't see anything on the floor of the garage or running along the frame.

We'll see what happens when I get it out of the garage and take home plate off - probably on Friday.
 

·
Registered
Joined
·
8,536 Posts
OP

after shutting off the car, pull the rubber elbow off the FPR. If there is any sign of fuel the diaphragm in the FPR is bad so replace FPR. You will need the right fuel line removal tool. Most auto part stores have them.

Before you remove the FPR, or fuel filter, release fuel pressure by pressing the Schrader valve with a rag over it to purge fuel. If engine is hot, wait until it cools off before doing this

BTW, does it take a longer crank time to start??

if so that is another sign of leaking FPR
 

·
Registered
Joined
·
426 Posts
Discussion Starter #7
Now that you mention it, the last time that I used the car, it may have taken an extra crank to turn over. About 10 miles later is when I smelled the gas. I work from home now so I didn't have to go anywhere the last 5 days. I was going to pull my FSM to see what tools I would need. I changed one of these FPR before in a different car and I forget what all I will need. I have a set of 6 of the A/C or Fuel Line disconnect fittings to depress the clips so taking the fuel line off should not be an issue. Thanks for pointing that out so that I can get the set out before I dig into the engine compartment.
 

·
Premium Member
Joined
·
4,985 Posts
You might want to try jumping the fuel pump bypass ( red wire near AC drier ) with the engine off, cold.
Look for dampness around injectors, fuel rail cross over, regulator, etc.

There is also a fuel line coupling inside the left frame rail, just behind the front wheel

Very often, a small leak will never be seen on a warm engine as the fuel vaporizes.

After about 4-5 minutes, try starting the car.
If it is at all reluctant cranking, you may have an internally leaking injector.
Not typically a cause of a running smell but something to look out for having the fuel pump running with the engine not running.
 

·
Registered
Joined
·
426 Posts
Discussion Starter #9
I just pulled out my copy of the Factory 1996 B-body Service Manual. It appears that the fuel line is fastened to the FPR with a clip that pops off - not the special connectors that are used in other fuel and A/C locations. I guess that I'll find out when I dive in. The FSM also says that I should remove the entire fuel rail but I don't remember doing that on the 1996 Caprice when I changed that FPR a number of years ago.
 

·
Registered
Joined
·
1,216 Posts
A fuel gauge is always helpful to diagnose something fuel related. If after turning engine off fuel pressure goes down fast - there is a leak in the system. It can be fuel pump check valve, FPR, injectors, fuel lines/connections. You name it. But if the pressure stays for a long time, you do not have a leak.
 
1 - 10 of 10 Posts
Top