Gasoline Odor

[EddieC]

The fuel pump sits in a recessed area in the top of the tank. I can be very likely the pump or it's lines have corroded enough to develop some pinhole leaks that would puddle in the recessed area but not enough to run down the sides of that tank. You can try to reach your hand in up there to feel if it is wet. I had a bad fuel odor for over a year before I figured it out. There was no sign of a fuel leak from under the vehicle.


View attachment 460058

That's nasty.
Is that toward the rear of the tank where it can be seen through the drivers rear wheel well after removing the liner? If that is the spot then I saw that area dry about a month ago. The odor was less frequent and less strong then so perhaps it's something else.

 

[EddieC]

The collective knowledge is helpful.

 

[rdezs]

The emissions drive cycle requires many conditions to be met, so it's not done every time the engine is started. It will only test on a cold start, for example, with the ECT and the ambient temps being within 'x' degrees. There are other conditions for it to perform the test.

Your dash message was likely the first occurrence of the emission test failure -- a pending code. The next time it failed (within a certain number of key cycles), the MIL would light up.

How do you think it determined the gas cap was loose, versus a leak in the vapor system? Lucky guess by the ECM? After all, between the tank and the gas cap there are no sensors. LOL, at least it was correct

 

[Fless]

How do you think it determined the gas cap was loose, versus a leak in the vapor system? Lucky guess by the ECM? After all, between the tank and the gas cap there are no sensors. LOL, at least it was correct

It ran the test and the leak was large; at that point its first guess is the gas cap. Bet that the pending code would be for a large leak.

 

[rdezs]

I may get the Tech 2 out after I get home from work and check the historical codes out of curiosity.

You know how it says on the cap to tighten until you hear one click? The cap still went on tight, you just couldn't make it click. I'm wondering if that one click closes some sort of diaphragm inside the cap to complete the seal?

 

[EddieC]

'89 Suburban
You nailed it on the pump exposure/condition.
Replaced and issue solved.

 

[Fless]

'89 Suburban
You nailed it on the pump exposure/condition.
Replaced and issue solved.

Let's make sure @89Suburban gets tagged like this, or he might not see it. Start a "tag" with the "@" symbol and start typing the member's name, and select from the dropdown list.

 

[EddieC]

Deleted for redundancy

 

[89Suburban]

Deleted for redundancy

Thank you @EddieC

Good job yourself keeping at it and figuring it out.

 

[EddieC]

So new issue shows right after the pump was replaced.
The gas gage is very inaccurate. Filled that tank and it showed full but went to 1/2 tank with only 8 gallons used from full. The computer readout is correct showing 8 gallons used.
I filled the tank again and it shows full but I haven't run any more gas out yet.

Something need resetting or was the installation screwed up?

 

[rdezs]

Did you use a genuine GM ACDelco, or a Delphi fuel pump assembly? The cheap aftermarket are nothing but problems, and not worth trying unless you like to keep dropping your tank.

Also, when you pulled your fuel pump out of the box, did you make sure and snap the float arm into place on the pump assembly?

If it is a genuine GM AC Delco or Delphi, double check that it's the correct application.

 

[EddieC]

Did you use a genuine GM ACDelco, or a Delphi fuel pump assembly? The cheap aftermarket are nothing but problems, and not worth trying unless you like to keep dropping your tank.

Also, when you pulled your fuel pump out of the box, did you make sure and snap the float arm into place on the pump assembly?

If it is a genuine GM AC Delco or Delphi, double check that it's the correct application.

Mechanic at private shop did it. I don't know the brand but it was about $400 for the part.
I tried to disconnect the battery to see if anything resets but the verdict is still out on the effectiveness because I haven't used much gas from the full tank (4 gallons).
It is soon after the replacement service so I can go back but I thought it worth trying any easy solutions first and I wouldn't bring it back with a full tank because of the weight.

 

[rdezs]

I wonder how many shops charge $400 for one of the $60 cheap Chinese ones.....

 

[EddieC]

I wonder how many shops charge $400 for one of the $60 cheap Chinese ones.....

I trust he uses the brands that he believes in. He has done free warranty replacements for us well past the warranty period when something went wrong with a MOOG suspension part.
I have also had the truck in there three times and for other things and could not talk him into taking payment so the old family ties seem to be in place.
I think he uses NAPA as a supplier.

 

[rdezs]

While Napa's in-house brand has some pretty good stuff, like their oil filters are made by wix...
There is not an aftermarket maker of the fuel pump that is worth installing. And $400 is more than what an oem genuine GM ACDelco costs.... You might want to ask him what brand it was.

 

[Fless]

Why not call your mechanic and explain what you're experiencing, and see if he has any suggestions before you bring it in for him to look at?

Your invoice should have part numbers on it to look up the manufacturer.

 

[solli5pack]

I wonder how many shops charge $400 for one of the $60 cheap Chinese ones.....

Too many..that's why Im laying on my back in the driveway destroying my body.

 

[rdezs]

Too many..that's why Im laying on my back in the driveway destroying my body.

It's only bad when you have to get up off the ground. That's getting harder every year. Making sure that creeper doesn't roll out from under you when you're halfway up. And don't even torture yourself when you're done by pondering how many times you got up and got back down, LOL.

 

[rdezs]

I kid you not..... I have grabbed a couple tools I needed down there, got interrupted by a short call, got all the way down there and realized I left those tools on the workbench. And not just once over the it's been of a job, then maybe two three or four times on a full weekend job. Ouch

 

[89Suburban]

Too many..that's why Im laying on my back in the driveway destroying my body.

There is another way . . .