1990 Cabriolet Fuel Smell

2347 Views 26 Replies 5 Participants Last post by loewenwolf, 11 d ago

loewenwolf

Discussion Starter · 17 d ago (Edited)

I've read over lots of the forums here, and I think I have a good idea where I need to look/inspect. Hoping someone can look at these symptoms and maybe say "hey that is...."

Symptoms:
-Intermittent Smell inside and outside of raw gas, usually when hot, but sometimes when cold. Usually outside only, but now inside, and most recently in the trunk.

-Spitting raw fuel (very little, but definitely raw fuel) out the tailpipe when engine cold ***EDIT there was such a strong smell coming from the rear that I convinced myself it was fuel, when it was in fact water.

-Starts have become a little harder occasionally when cold or hot? Fuel pump going? Sounds very similar to when the car struggled to hot start before switching to battery cables...like hesitates, clunks, then goes.

Things I've done:

Inspect under gas tank/filler and wasn't able to notice obvious fuel, but did see some rust near filler (photo below)

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New item by Kurt Loewen

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Lift up back seat and inspect/smell around sender and didn't smell/see fuel too obviously until my face was directly in front of it, then got a bit of gas smell (should I change this seal either way?)

Ideas:
Injectors?
Fuel pump/sender?
Fuel rail or something similar?
Charcoal canister?

I know, based on the vintage, and condition of the car it is likely not one thing. But to deal primarily with the fuel smell I'm hoping someone might have a Eureka based on this info.

THANK YOU!

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lobstervector

· #2 · 17 d ago

You said you had your rear seat out so you probably checked this, but last time I had that problem, it turned out to be the fuel line coming out of the tank. I don't know if yours is set up like my '87 Cabby, but the line coming out of the sender goes around the front of tank, had lost its aged foam insulation and was abraded to the point of weeping fuel.

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loewenwolf

Discussion Starter · #3 · 17 d ago

lobstervector said:
You said you had your rear seat out so you probably checked this, but last time I had that problem, it turned out to be the fuel line coming out of the tank. I don't know if yours is set up like my '87 Cabby, but the line coming out of the sender goes around the front of tank, had lost its aged foam insulation and was abraded to the point of weeping fuel.
View attachment 290044

Thank you for this idea. I didn't see that, but will be under the car again and will absolutely look for that.

lobstervector

· #4 · 17 d ago

Lots of places to check, but to be clear, I found the problem from the top side. Under the rear seat. Forward of the fuel pump/sender unit, the hose goes down over the top/front corner of the tank. Good luck tracking it down.

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briano1234

· #5 · 17 d ago

Take the rear seat out. Verify that your inspection cover is dry. Remove the cover and inspect the sending unit of the car, look around it for leaks and weeping fuel, if you don't have fuel clamps on the hoses they can oblong the fuel line and weep fuel. Fuel Line clamps close circularly screw type can oblong when too large and are overly tightened.
Look under the car at the fuel filter.

The look at your fuel lines two of them one for fuel in to the FPR bottom and one that is ont he side that is the fuel return on the firewall. There was a TSB on them IIRC for the rubber hoses cracking and or loosening and leaking fuel. I had that one on my Green Cabriolet.

You may have cracked fuel lines from the tank to the Sump/Filter and to where they connect to the hard lines.

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loewenwolf

Discussion Starter · #6 · 17 d ago

briano1234 said:
Take the rear seat out. Verify that your inspection cover is dry. Remove the cover and inspect the sending unit of the car, look around it for leaks and weeping fuel, if you don't have fuel clamps on the hoses they can oblong the fuel line and weep fuel. Fuel Line clamps close circularly screw type can oblong when too large and are overly tightened.
Look under the car at the fuel filter.

The look at your fuel lines two of them one for fuel in to the FPR bottom and one that is ont he side that is the fuel return on the firewall. There was a TSB on them IIRC for the rubber hoses cracking and or loosening and leaking fuel. I had that one on my Green Cabriolet.

You may have cracked fuel lines from the tank to the Sump/Filter and to where they connect to the hard lines.

Thanks for the information Lobster, will check your idea tomorrow.

Briano, thanks for the information, so helpful as always. FPR is.... Fuel Pump Regulator?

briano1234

· #7 · 17 d ago

FPR Fuel Pressure Regulator. It is attached to the (as you look at the engine) left side of the fuel rail.

loewenwolf

Discussion Starter · #8 · 16 d ago (Edited)

briano1234 said:
FPR Fuel Pressure Regulator. It is attached to the (as you look at the engine) left side of the fuel rail.

FPR Fuel Pressure Regulator. It is attached to the (as you look at the engine) left side of the fuel rail.
[/QUOTE]

Still nothing Definitive. But took lots of photos.

1. FPR and lines to/from it. Note the firewall line, could that be my problem..some rust there but only on the hanger it seems? Or the frayed at end line to the rail?

https://photos.app.goo.gl/tFUpYRiLZjMuqWyu6

2. Sender Seal is clean/dry and no obvious breaks in any of the lines there...or where Lobster had me look.

https://photos.app.goo.gl/3PHfrU3g2uF1hynj9

3. Filler neck. Again no obvious leaks but pretty corroded near the fill point.

https://photos.app.goo.gl/eSUx3R82cqcYqqBm6

4. Fuel filter/sump going back towards to the tank. You can see on the one side of the Fuel Filter the line is pretty rough...but also doesn't appear to be leaking. And then toward the pump/tank the lines get super corroded...and I'll admit it is pretty smelly around here. Feel like this maybe my problem?

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4 new items by Kurt Loewen

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You all are legends. Thanks for taking the time!

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loewenwolf

Discussion Starter · #9 · 15 d ago

briano1234 said:
FPR Fuel Pressure Regulator. It is attached to the (as you look at the engine) left side of the fuel rail.

Hi Briano based on my previous post do you think there is anything to go on? If cracked fuel lines near sump/filter (see group of pictures #4), is this.something I can take on?

Thanks
K

briano1234

· #10 · 15 d ago

If you smell gas at the Fuel pumps, is there a loud whine from the Right rear wheel arch when you start and run the Car?

It could be that your IN-Tank Pump interconnect hose is holed or failed and that the Pump can or could be dangeling from the intake. This causes the Primary fuel pump having to Draw fuel from the tank instead of the pumps sump/filter. It can also cause over pressurization in the Tank, causing a weird fuel smell.

Here are ETKA's snaps of your entire fuel related system. Number 22 is the Filter/sump it is made from Plastic and is brittle Clipped to right rear side of the tank.

Also if you can run your fingers around the seam of the tank to see if it is leaking would be a good thing but I would wear gloves. I also see that you have OEM hoses still attached to things, I would replace them with new rubber hoses as they could of cracked or loosened and you have Vacuum leaks which can cause havoc with running. There is a Idle By-Pass Screw on the rear of the Throttle body, if you can turn that with your fingers then it has a bad o-ring and needs to be replaced.

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loewenwolf

Discussion Starter · #11 · 15 d ago

briano1234 said:
If you smell gas at the Fuel pumps, is there a loud whine from the Right rear wheel arch when you start and run the Car?

It could be that your IN-Tank Pump interconnect hose is holed or failed and that the Pump can or could be dangeling from the intake. This causes the Primary fuel pump having to Draw fuel from the tank instead of the pumps sump/filter. It can also cause over pressurization in the Tank, causing a weird fuel smell.

Here are ETKA's snaps of your entire fuel related system. Number 22 is the Filter/sump it is made from Plastic and is brittle Clipped to right rear side of the tank.

Also if you can run your fingers around the seam of the tank to see if it is leaking would be a good thing but I would wear gloves. I also see that you have OEM hoses still attached to things, I would replace them with new rubber hoses as they could of cracked or loosened and you have Vacuum leaks which can cause havoc with running. There is a Idle By-Pass Screw on the rear of the Throttle body, if you can turn that with your fingers then it has a bad o-ring and needs to be replaced.

View attachment 290736

View attachment 290735

View attachment 290737

Great information. Nah the classic wheezing inst what I'm hearing only that the pump "pumps" when ignition engaged...a short burst and off.

I will do some diligence on the hoses. But inspecting that number 22 you pointed out is a big pain as I don't have a lift and I could see it last time I was under, it appears to be buried behind some body, hoses and bad access. Remove the wheel and rocker panels for access?

RoccoGen2

· #12 · 14 d ago

A few years ago my car also emitted an intermittent smell of gas, but on the outside only. Strongest close to the external fuel pump. Hose 31 in Briano’s post had developed cracks and was seeping - replaced. Yours looks aged, but I didn’t see any dark patches suggesting a seep. In that area a small mirror helps to look around obstacles to confirm.

loewenwolf

Discussion Starter · #13 · 14 d ago

RoccoGen2 said:
A few years ago my car also emitted an intermittent smell of gas, but on the outside only. Strongest close to the external fuel pump. Hose 31 in Briano’s post had developed cracks and was seeping - replaced. Yours looks aged, but I didn’t see any dark patches suggesting a seep. In that area a small mirror helps to look around obstacles to confirm.

Great information and thank you Rocco. And ya, I should clarify that seeing my problem and actually gaining access to it are two different things. I think that one of my problem parts is a super rusted out #15 on Briano's diagram, just a metal line. Access there seems awfully tricky, would either of you recommend removing a rocker panel for access? If I do get to it, the only replacement part I can find is on eBay. Any of y'all make these yourself out of raw materials/moreso universal parts? Suggestions?

The tank itself doesn't seem to be leaking thank goodness, though checking by the rust that could definitely happen.

Briano thanks for the encouragement to replace old lines generally, this is my GF's daily driver so I only get to actually work on it every week or two for an afternoon so always trying to stockpile projects to get done on it.

Will double check on the throttle body.

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RoccoGen2

· #14 · 13 d ago

Yes, after a quick search looks like #15 is available on eBay and from Heritage Parts Centre. I'm planning to replace all the fuel lines in that area including the plastic sump filter later. From what I've read on this topic, dropping the rear beam on the right side by a few inches is helpful. See if you can confirm the leak source before going there.

loewenwolf

Discussion Starter · #15 · 13 d ago

RoccoGen2 said:
Yes, after a quick search looks like #15 is available on eBay and from Heritage Parts Centre. I'm planning to replace all the fuel lines in that area including the plastic sump filter later. From what I've read on this topic, dropping the rear beam on the right side by a few inches is helpful. See if you can confirm the leak source before going there.

Ya it is, but it's like $150 for a 6 inch piece of metal tubing. I might contact some parts places in town and see what they might be able to fab up for me.

And I totally agree about everything else said here, dropping the rear beam seems like a last resort only if I have to get in there. So far, it seems to me that is where my leak is coming from, just need to get a better look.

Thanks again.

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loewenwolf

Discussion Starter · #16 · 13 d ago

briano1234 said:
If you smell gas at the Fuel pumps, is there a loud whine from the Right rear wheel arch when you start and run the Car?

It could be that your IN-Tank Pump interconnect hose is holed or failed and that the Pump can or could be dangeling from the intake. This causes the Primary fuel pump having to Draw fuel from the tank instead of the pumps sump/filter. It can also cause over pressurization in the Tank, causing a weird fuel smell.

Here are ETKA's snaps of your entire fuel related system. Number 22 is the Filter/sump it is made from Plastic and is brittle Clipped to right rear side of the tank.

Also if you can run your fingers around the seam of the tank to see if it is leaking would be a good thing but I would wear gloves. I also see that you have OEM hoses still attached to things, I would replace them with new rubber hoses as they could of cracked or loosened and you have Vacuum leaks which can cause havoc with running. There is a Idle By-Pass Screw on the rear of the Throttle body, if you can turn that with your fingers then it has a bad o-ring and needs to be replaced.

View attachment 290736

View attachment 290735

View attachment 290737

Ok so I got my head really close to the Pump (number 40 in your first diagram Briano), and made a video while engine running. You can only hear what I'm hearing near the end of the video as I get the mic closer to the pump, the higher pitched whirring. To me this is not super loud or whining and sounds like a pump doing it's job. But I also don't know, Can you hear it over the engine what I'm talking about? This is where the smell is coming to be doubly clear.

https://photos.app.goo.gl/ikxLfLuTxQVEHB898

briano1234

· #17 · 13 d ago

Nope, it don't sound Normal to me. I would inspect your in-tank pump, and connection hose
Your pump is devoid of the Surround foam and hanging bracket. But that is ok, I had that on my 92.

www.volkswagenownersclub.com

1984.5-1993 mk1 How to change your in-tank fuel pump

How-to change your in-tank fuel pump. ########################################################################### WARNINGS Do it in a well ventilated area Scoot the seat fully forward and have all your tools ready. OPEN YOUR TOP...

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www.volkswagenownersclub.com

tinygiant

· #18 · 13 d ago

I just replaced my external pump for the same reasons. I found that the banjo was double washered and thought that it may be the reason for the smell. I also found that my foam surround was soaked in what seemed like old fuel.

i wanted to replace my metal pipe too, but decided against it. I did not feel like undoing the very surface rusty clamps on the plastic tank up top. I knew if i tried undoing those I would kill the nipples on that tank. If at some point i am smelling fuel again i will order a new plastic tank and do everything. So far it seems okay since the swap out last night.

loewenwolf

Discussion Starter · #19 · 13 d ago

tinygiant said:
I just replaced my external pump for the same reasons. I found that the banjo was double washered and thought that it may be the reason for the smell. I also found that my foam surround was soaked in what seemed like old fuel.

i wanted to replace my metal pipe too, but decided against it. I did not feel like undoing the very surface rusty clamps on the plastic tank up top. I knew if i tried undoing those I would kill the nipples on that tank. If at some point i am smelling fuel again i will order a new plastic tank and do everything. So far it seems okay since the swap out last night.

tinygiant said:
I just replaced my external pump for the same reasons. I found that the banjo was double washered and thought that it may be the reason for the smell. I also found that my foam surround was soaked in what seemed like old fuel.

i wanted to replace my metal pipe too, but decided against it. I did not feel like undoing the very surface rusty clamps on the plastic tank up top. I knew if i tried undoing those I would kill the nipples on that tank. If at some point i am smelling fuel again i will order a new plastic tank and do everything. So far it seems okay since the swap out last night.

Briano will give your step by step a try and report back.

Tinygiant, so you didn't touch the In Tank pump at all? Can you clarify for me what the banjo is you speak of? A bolt/fastener on a particular side of the pump?

I feel like I'm getting closer to a solution.

tinygiant

· #20 · 13 d ago

I replaced my tank pump 3 years ago.

on the external pump there is a small hose with banjo on the outlet side that it connects to the accumulator with.

the banjo has a two crush washers. One on each side.

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