Raw gas smell

[snakebit]

Since installing my coldside in Oct. 07, I've noticed a strong smell of raw gas soon after startup on about four occasions. Most recently, P0401 followed immediately. It may have occurred more times when I didn't notice because the top was down.

Evap canister? Runs like a champ otherwise.

I just took a look under the hood. It might be my imagination, but when I unscrewed the oil fill cap and took a whiff, it seems to smell a bit gassy. No other gas odors to be found.

[Tom @ Fast Forward]

Sparkplugs tight?

No smell until you start?

Smell goes away right after starting?

[mywong23]

check all the gas line connections. especially when engine is cold, feel all the hose ends.

mine was leaking occassionally from the end of the hose connected to the 5th injector. At first I thought the A/C sensor was rubbing against the hose. anyway, I think the 5/16" hose diameter might be a touch big and will be trying a 1/4" line soon.
use the screw clamps that surround the hose, not the worm screw clamp with slits.

raw gas could leak out and fall onto air filter, causing a CEL code (mixutre too rich).

once engine heats up, the raw gas might evaporate more quickly, so you may not detect any smell. also the fuel line might expand a bit with the heat and may make a better seal and not leak.

use fuel injector hose, not fuel/emissions hose, as the injector line can handle higher pressures.

[snakebit]

Sparkplugs tight?Yes.
No smell until you start?Right.
Smell goes away right after starting?Yes, pretty quickly - maybe 30 sec.
check all the gas line connections. especially when engine is cold, feel all the hose ends.All seem snug.
use the screw clamps that surround the hose, not the worm screw clamp with slits.Yes.
raw gas could leak out and fall onto air filter, causing a CEL code (mixutre too rich).I'm using the stock air box.

[Tom @ Fast Forward]

Does it start smooth or show signs of starting rich/rough?

[snakebit]

Starts smooth.

[bogey]

Do you have an intact catalytic converter? A hollowed out or missing converter will smell like gas.

What about putting the key in ON position, and letting the fuel pump run to pressurize the system. This can be done by jumpering the FPU and GND on the diagnotics connecter under the hood. Then check for fuel leaks.

Could the vacuum lines on the purge control valve be reversed or disconnected causing the venting of fumes?

[mx3jmcb]

Check your injectors....the upper seal can get damaged when installing the fuel rail. Put your finger under the injectors and check for any sign of leakage.

[snakebit]

Cat is good. I'll pressurize and check for leaks as soon as I have a moment. The odor does seem to come from the evap canister.

[Tom @ Fast Forward]

Bad gas cap?

[snakebit]

Bad gas cap?Would a gas cap cause gas odor under the hood? I'm pretty sure that's where it's coming from.

[Tom @ Fast Forward]

It's all inter-related.

[snakebit]

How does one test a gas cap?

[Kyp J]

How does one test a gas cap?

Turn the car upside down and shake it?

Sorry, couldn't resist. Nobody else had anything so I had to.

Here in TX they do a yearly safety check for a window sticker and one of the steps is to check the pressure holding capability of the gas cap. So they must make a tester for it. It requires a lot of adapters for the tester apparently. Easier and cheaper to buy a new gas cap. I just got a new one for the Jeep when my wife left it on the bumper after filling up and it only cost $7.

[Kyp J]

Another idea. Take off the intake hose, open throttle plate and sniff at the throttle body. Maybe 5th injector leaking into intake manifold.

[snakebit]

Do you have an intact catalytic converter? A hollowed out or missing converter will smell like gas.

What about putting the key in ON position, and letting the fuel pump run to pressurize the system. This can be done by jumpering the FPU and GND on the diagnotics connecter under the hood. Then check for fuel leaks.

Could the vacuum lines on the purge control valve be reversed or disconnected causing the venting of fumes?Bogey, how do I identify the FPU and GND pins?

[bogey]

The diagnostic connector is labled. It is on the drivers side near the shock mount.

Key in ignition to ON (do not start), use a wire jumper between GND and FP. You should hear the fuel pump run to pressurize the system. Then inspect for leaks.

[snakebit]

The diagnostic connector is labled. It is on the drivers side near the shock mount.

Key in ignition to ON (do not start), use a wire jumper between GND and FP. You should hear the fuel pump run to pressurize the system. Then inspect for leaks.Thanks, but my question is: which exact pins or slots are GND and FP? There are no labels of any kind in my diagnostics box. It looks like this:

A B--C D
E F G H I J K
L M N O P Q
------------
R S T U V W
X---------Y

Only slots B, C, D, E, K, R, S, T and V have terminals in them.
For some reason I had taken a Sharpie and highlighted C and T at some point; are those GND and FP?
I don't want to jump the wrong ones, in case that can cause problems.

[bogey]

T is GND

V is FP

According to 99 FSM...

[snakebit]

Well, no visible leaks from pressurized system. I suspect the charcoal canister is saturated. When I pull a hose and sniff the canister, it smells pretty gassy. Could a bad gas cap have caused that? I don't want to get a new canister and just have it flood again.