[andylarry]

I haven't read every post, perhaps this was covered. Shouldn't the vapor line be the one on the steel connector tube above the tank just below the fuel cap?

 

[Lin]

Of course, with the time change in the UK, they are closed. I emailed them and posed the question.
Lin

 

[andylarry]

Nope, I was wrong. I just looked at my 86, and it is in the top of the tank, not the tube.

 

[Gubi]

You should post a separate thread "Does anyone have a S3/S4 tank out of the car they can look at for me?". Someone's gotta have one lying around, they can tell you how the pipes should be.

 

[Lin]

A couple of days ago I started a separate thread: 87 Spider Fuel Tank Question

But, I can try again with your title.
Lin

 

[andylarry]

@Lin , Side bar. My brother had a 59-60 bug eye. For some reason I still have the PA title. My first car was a 67 Midget with the "hot" 1275 mechanical advance ignition distributor. Funny story, I purchased it when I was 15 (not of legal age to drive), put her in the unused garage under the house and removed the engine with a friend. I then disassembled the engine (no prior automotive experience, I had a repair manual ) and then sent the block and crank, flywheel and head out for machining. When I got them back, it was too cold to work in the garage, so I made an area in my bedroom to paint the block, and head and reassemble the engine. I used as many parts that I could afford to purchase ( paper route, grass cutting, snow shoveling ) from the Joe Huffaker catalog. Pistons, cam, pushrods, etc. and I lightened the rockers. I got it all back together, and I then realized that it was way too heavy for me to carry down the steps from the second floor. Negotiating the engine with my older brother out of the house and into the garage was a feat. The engine ran great. I got a new set of Michelin XZX tires mounted on my wire wheels, a tweed cap and a pair of perforated driving gloves. I thought that I was Sterling Moss. Good times...

 

[Lin]

@Lin , Side bar. My brother had a 59-60 bug eye. For some reason I still have the PA title. My first car was a 67 Midget with the "hot" 1275 mechanical advance ignition distributor. Funny story, I purchased it when I was 15 (not of legal age to drive), put her in the unused garage under the house and removed the engine with a friend. I then disassembled the engine (no prior automotive experience, I had a repair manual ) and then sent the block and crank, flywheel and head out for machining. When I got them back, it was too cold to work in the garage, so I made an area in my bedroom to paint the block, and head and reassemble the engine. I used as many parts that I could afford to purchase ( paper route, grass cutting, snow shoveling ) from the Joe Huffaker catalog. Pistons, cam, pushrods, etc. and I lightened the rockers. I got it all back together, and I then realized that it was way too heavy for me to carry down the steps from the second floor. Negotiating the engine with my older brother out of the house and into the garage was a feat. The engine ran great. I got a new set of Michelin XZX tires mounted on my wire wheels, a tweed cap and a pair of perforated driving gloves. I thought that I was Sterling Moss. Good times...

Great story. I have similar stories with my 60 Big Healey.
Lin

 

[Lin]

I have heard back from Classic Alfa and while they were helpful and gracious, I didn’t learn a great deal. Bottom line is that they checked another tank for me and said that the longer pipe (return line) extends to almost the bottom of the tank. The pipe for the vapor extends an inch or so below the top of the tank. I think mine may be longer than an inch, but regardless even if it extends an inch below the top the end of the pipe would be in the liquid fuel. They said that they have sold 17 of the tanks in the last year and have no reported problems. They did give me contact information for Alfa Performance Connection in Orange, CA and suggested that I contact them since they had purchased three tanks this year.

I have written Alfa Performance Connection given them the background and asked for them to reply by email or a call. I have offered to pay for their time, but I will certainly understand if they don’t respond given that I am not a customer. I sure wish someone with an old tank would respond, but I have not gotten any helpful responses on that new thread. I am hesitant to start “digging in” further and taking things apart before the simple question of the vapor pipe in the liquid fuel gets definitively answered.

I just want to say that I have been a member of at least four other forums and/or bulletin boards. Porsche, Jaguar, Healey and MG. You guys are the best! However this may get resolved. Thanks so much.
Lin

 

[spiderserie4]

but the vapour extending an inch below the top (CA checking their stock) and on yours an inch and a half, maybe two inch from the bottom is surely a difference?

Personally I'd just remove the vapour hose at the tank itself (stick a little bung onto that outlet, or tape it up), and see if things improve when you start it.

 

[andylarry]

Have you tried to (maybe with a helper) blow into the vapor hose (towards the tank) and listen for either hissing (or nothing), or gurgling? Of course with the fuel cap off. Sorry, if this was covered.

 

[Lin]

I don’t want to be overly optimistic, but I may have happened onto the problem, and it requires circling back to where we started. This afternoon I went into the garage and just stared at the engine for a while. For no particular reason I was curious if any fuel had made its way into the oil vapor separator. I pulled the top vacuum hose (of the three) off of the plenum that goes to the OVS. The end of the hose was dry. I then pulled the lowest one of the three that goes to the charcoal canister which was already disconnected from the canister. It was also dry. I then pulled the center hose from the plenum that connects to the fuel pressure regulator and gasoline spilled out! I then pulled the same hose off the top of the fuel pressure regulator and yep it was wet too.

I cannot explain why after a couple of examinations and a vacuum test that the regulator seemed to function properly before. Just don’t know. We ran the car yesterday so I guess the fuel flow was fresh.

So, maybe the FPR is the problem after all? What do you think? I suppose that if enough fuel flowed into the plenum when this first happened it could have entered the lowest vacuum hose and flowed to the charcoal canister. This does explain something for me. I could not understand why, if the fuel in the charcoal canister was coming from the fuel tank, that the vapor reservoir in the trunk had no fuel in it. The inlet to that reservoir from the fuel tank is at the bottom of the tank. The outflow is at the very top. So, the tank would have to fill fully before it would reach a level where fuel would flow out the top through the hose to the front of the car and the charcoal canister.

The FPR failure may explain the fuel in the charcoal canister.

Anyway, I am soaking that big nut attaching the FPR to the fuel rail with Kroil. I will do that for A couple of days and then try to loosen it without stressing the fuel rail. If it looks like that won’t happen, I will remove the fuel rail with the FPR and put it in a vice to break it free and then replace the FPR.

I will keep you posted.
Lin

 

[spiderserie4]

there you go....fuel out the FPR vacuum line....not good

hopefully that is it as this had us all going nuts

get a Bosch oem, I would, there have been poor aftermarket FPRs that you read have caused trouble on here from time to time....

 

[Gubi]

hopefully that is it as this had us all going nuts

Yeah, no joke there.

I still don't see how an FPR dumping fuel into the plenum could cause fuel to be in the intake hose on the other side of the throttle plate? But I have no better ideas.

 

[Lin]

As I said, I am not going to get my hopes up, but fuel in the vacuum hose sure makes that FPR look bad. I have a Bosch replacement on the workbench. Thanks everyone.
Lin

 

[spiderserie4]

I pulled the top vacuum hose (of the three) off of the plenum that goes to the OVS. The end of the hose was dry.
I then pulled the lowest one of the three that goes to the charcoal canister which was already disconnected from the canister. It was also dry.
I then pulled the center hose from the plenum that connects to the fuel pressure regulator and gasoline spilled out!

I somehow doubt it makes a huge difference, but your order of 'nipples' seems incorrect according to this photo
those nipples have different diameter holes (different vacuum pull I'd imagine)

the fact the charcoal canister hose was dry is I guess due to the fact it wasn't connected when you started the car....
That the charcoal can had fuel in it is still something worrying.....the plenum line is under vacuum, so even if the plenum was swishing around in fuel how can it get into the can...?
imo, it can't
it must come from the tank

still, report back when the new FPR is in and see how that does.
it's all a mystery!

 

[Lin]

Dom, of course, you are completely correct about the order of the vacuum hoses. I reported incorrectly. The top is the fuel pressure regulator. The middle is the OVS, and the lowest is the charcoal canister. That is how mine are. Interesting about the different diameter nipples though. There is a lot to learn about this Bosch system.
Thanks again!
Lin

 

[Gubi]

Well, no harm in trying a new FPR in any case. Try it with the new FPR and vapor system disconnected first, then work from there: it sounds like it was running mostly okay with the vapor system plugged.

FYI, I was thinking about the stalling during your test and my guess is that's due to lack of idle air. At normal idle, the plenum pulls a bit of air from the intake hose through the carbon canister (bypassing the throttle plate). So with those canister hoses plugged you'd have less air at idle, which might have been enough to drop the idle to where it wanted to stall. You might try opening up the idle bypass during the test to set idle to the proper ~950 and see if that helps. Then you can see how it runs with the new FPR alone, then after that hook up the vapor system again and try that way.

 

[Lin]

Will do.
Lin

 

[Gubi]

Also note that until you rule out the tank issue, I'd assume there's the possibility of fuel coming out of that vapor hose from the tank. So keep an eye on that and keep safety in mind during any tests just in case.

 

[spiderserie4]

^^
what I'd do if it were mine:
I'd fit the new FPR, then put the charcoal can back on (don't close the fender compartment up just yet, just connect the can as it would be normally)
then remove the vapour hose at the top of the tank (thus that hose will only draw air)

Now start her up and see what's what.

yes a disconnected hose at the tank might cause false air, but I think it will be sufficiently minor as it it being dragged thru those nicely (hopefully by now) dried out charcoal pellets.