Runs poorly when hot

[artmunson]

I have a '79 Spider and about a year ago I decided I had wasted enough time and money trying to make the stock set-up work properly and stop leaking fuel so I bought a used "single plane" manifold from an older Spider and new Webber carb(32/32 I think)from Bruces parts bin.It was well worth the money however I have been experiencing a runability problem that seems to be getting worse.If I have been driving for a while(full temp)then park the car for 5-20 minutes,when I start driving again it idles very low and surges terribly for the first 2 miles or so.I am thinking the fuel must be boiling in the bowl?Maybe if I put a thicker insulater under the carb?I have a feeling I am not the first person with this problem.Any thoughts?TIA

[So Cal Mark]

I've seen it many times, fuel will boil during a heat soak. Try one of the phenolic insulators rather than just a paper base gasket. It's pretty easy to check for fuel boiling and spilling over after you shut it off. The cooling fan should run after shut off until the temp drops, does your fan run after parking?

[artmunson]

Mark,
Thanks for the reply.Do you know where I could get a phenolic insulator?I heard they used to use insulators from '73 Pintos.
Art

[manoa matt]

Is your carb a 32 ADFA? What kind of fuel pump do you have, mechanical or electric? If you got a mechanical pump and the 32 ADFA you should be running a fuel return line back to the tank with a one way valve near the carb to prevent vapor lock.

[So Cal Mark]

a return line won't help with fuel boiling after shut off, you need an insulator between the carb and manifold

[artmunson]

Manoa Matt,
I do have a mechanical pump,I do have a return line and I do have the "one-way" valve.Thanks for your help.
So Cal Mark,
I am hoping to have some time Monday to try a thicker insulator.I will let you guys know.
Art

[artmunson]

Mark,
I just read you prior post and realized I forgot to tell you that my fan doesnt come on untill the car gets to about 200f and most of the time the car runs at 190f.I am going to try the insulator and maybe even run a tube for cold air since mine doesnt have the stock air-cleaner anymore.
Art

[So Cal Mark]

the fan should come on at 195f, and battery power should be supplied to the fan so it can run even after the engine is shut off.

[mbouse]

umm, that one way valve.

does it look like a flying saucer?

pull it and see if your trouble disappears.

[artmunson]

Merry Christmas guys!Sorry I havent responded to your help.I havent had my car for a couple of weeks.As soon as I get it back I hope to work on it and will let you know then.The one way valve was functioning properly when I put the carb/manifold on last year...right now I cant remember what the heck it is supposed to do?????so I cant figure out how taking it off will fix anything?????????Isnt it there to keep the fuel in the fuel line/pump when the engine is turned off????I have been sitting here staring at the wall for 15 minutes!!!My head hurts!!!!

[artmunson]

just read the prior posts,should have done that first and I wouldnt have a headache right now.I will check the valve again when I get the car back.I was leaning heavily on the carb insulator but am now wondering.....the last time I drove it the outside temp was 35f,the car was pretty cold and yet it still had the problem.
So Cal Mark...do you still think that it could be the "heat soak" problem?It does have a thick gasket under the carb.I will still try a thicker/better insulator(maybe even a heat shield) first but just wondering what your thoughts are.

[So Cal Mark]

I'd suggest driving it, shutting it off with the air cleaner off. Then you can watch the carb venturi and see if you have fuel trickling in with the engine off

[artmunson]

Mark,
I was going to ask you earlier when you said it was easy to check for fuel boiling....thanks for the help.I will do just that and certainly let you know the outcome.
Thanks again for all the help,
Art

[artmunson]

Hello all,
I finally got my car back from my buddy...the clutch works great!He said it was a lot nicer/beefier than the one that was originally in it and the one he used last,we'll see how long it lasts,it makes a pretty loud "frictiony sshhh" noise when it starts to grab....he says that will go away soon.Anyone else have this happen...I never have.

As far as the way it is running now...he put a piece of pipe where that "thing" used to be in my exhaust(ya know)and WOW that really woke it up!!!It runs a lot better now!!!It pulls from 3 to 5k rpms WAY faster!!!As a matter of fact I never used to rev it past 4k because the power dropped off and it felt like it was going to go kapuut! It also SEEMS to be fixed as far as the "hard starting when hot" could that be possible???Clogged cat was making it run too rich???I think so...what do you think?It also SEEMS to not stink the garage up....sometimes I think I just want it to be fixed so bad that I imagine everything is fine....kinda like DENIAL!My wife will certainly let me know if it indeed does still STINK!I'll let ya all know soon.Thanks.

[pope]

Try a pine tree shaped air freshener on the rear mirror. Worked for Tommy Boy!