Installing 32/36 Weber and New Intake on my 79

[Pescado]

Here's a picture of my seals saturated and a drop forming on the washer circled in RED

[Pescado]

some info regarding the carb....pinched the fuel line and no leaking, removed pinch and carb started leaking again. Right now I have the fuel line pinched and I took the top of the carb off to make sure fuel is in the bowl...testing to see if I have a leak from the bowl.

[Pescado]

no leak from bowl....put things back together and attached fuel line. Let it sit for the night and later today found it leaking again, loosened the fuel fill cap and lots of pressure released so i'm thinking this is related but no idea how to go about fixing this....thoughts?

[18Fiatsandcounting]

Sounds like the vents to the gas tank are not operating as they should, so pressure builds up in the tank/fuel lines and forces its way out of the carburetor?

Are you sure the "whoosh" sound when opening the gas tank was pressure buildup, or air rushing in because of vacuum in the tank? They sound similar. Try running the car for a few days with the gas cap cracked slightly, and see if you still see the leakage on the carb.

-Bryan

[Pescado]

Good morning all,

Had the little Italian out and about the last few days and it's been fun. Pretty sure I got the ignition timing dialed in and have been playing around with the carb to get that tuned. Best part so far...after a good warm up and a spirited drive I pinned the pedal to see how the car reacts and oh BOY! We heard some sweet music come out the exhaust that we never heard before on this car...this little roadster has some attitude now and we love it! Driving this car is so much fun that it's becoming hard to park it on a nice day and work on it....but it does still need some work.

1. After the car warms up my RPM's get stuck around 2500, by stuck I mean it won't drop after acceleration...so in neutral it will idle at 2500 and climb's when accelerating but when I take my foot off the gas it settles back to 2500. Sometimes I can get it to go back to normal idle by popping the throttle, sometimes it won't. I did play around with the throttle linkage today to see if that's the problem but haven't tested yet.

2. Leaking carb...this one now remains a mystery as even with the fuel cap locked down I'm getting no leaking, for whatever reason this has just stopped. It could be the residents living in my haunted garage playing games with me...I'll keep an eye on this to see if the issue returns.

3.Carb tuning...on going.

More test driving today...sucks but someone has to do it

[18Fiatsandcounting]

1. After the car warms up my RPM's get stuck around 2500, by stuck I mean it won't drop after acceleration...

Sure sounds like a sticking throttle cable, linkage, or even something around the gas pedal that is preventing the pedal from coming all the way back up. Occasionally the linkages on the primary throttle shaft bind against the carb body, and this is often due to lack of lubrication, damage, or the nut on the end of the throttle shaft is too tight. Loosen the nut, but make sure to reclamp that locking washer around the nut as without it, the nut can loosen up after a while and then fall off. Been there, done that.... Also the locking washers aren't as good as they used to be, so you can only loosen and tighten them a couple times before the tab breaks off. The solution there is just a new locking tab washer.

-Bryan

[Pescado]

1. After the car warms up my RPM's get stuck around 2500, by stuck I mean it won't drop after acceleration...

Sure sounds like a sticking throttle cable, linkage, or even something around the gas pedal that is preventing the pedal from coming all the way back up. Occasionally the linkages on the primary throttle shaft bind against the carb body, and this is often due to lack of lubrication, damage, or the nut on the end of the throttle shaft is too tight. Loosen the nut, but make sure to reclamp that locking washer around the nut as without it, the nut can loosen up after a while and then fall off. Been there, done that.... Also the locking washers aren't as good as they used to be, so you can only loosen and tighten them a couple times before the tab breaks off. The solution there is just a new locking tab washer.

-Bryan

Well you warned me….had the car out for another test run and car was doing great. Seems like adjustments to the throttle linkage cured the sticking RPM’s so pulled into a dead end to turn back home and suddenly no acceleration…car just remains idling nicely and instantly that nut and washer came to mind. Open the hood…yup throttle assembly is in pieces. I push the car into a restaurant parking lot and start walking the street to see if I can find the nut…no luck just the lock washer was recovered. Tow truck?? Nope a light jog to Home Depot and bought a bunch of nuts and washers…light jog back and now I’m sweating and my little legs are shaking (perhaps it’s time to get back in the gym). Managed to get a nut on with a few treads and a bunch of washers to compress the assembly together….drove her home. Currently new nut and lock washer installed…this time really locked on a finger tight nut. I decided to do a compression test today and was a little shocked to see the results. Prior to all the new work done I had 150 across all cylinders….now after all the upgrades only 110. Also wanted to mention that while driving the car with the new 32/36 when I accelerate I hear a hissing sound from the engine, not sure if this is normal with this carb but I don’t recall hearing this with the original small carb.

[Nut124]

110psig, eh? Was the throttle open or closed when cranking for this test? Needs to be open.

Was anything done to the block, bores, pistons? If not, it is likely your intake cam timing is way retarded, like one full tooth.

[18Fiatsandcounting]

Yes, 110 is way low, like "time to rebuild the engine low"... I agree with Nut's suggestions.

But I'm also curious about the hissing sound. Vacuum leak? Can you recreate the sound in the driveway with the hood open by just revving the engine? Is the sound continuous or does it come and go, or pulsate?

-Bryan

[Pescado]

110psig, eh? Was the throttle open or closed when cranking for this test? Needs to be open.

Was anything done to the block, bores, pistons? If not, it is likely your intake cam timing is way retarded, like one full tooth.

I’m not sure that I had the throttle pressed down…I’ll do the test again. No mods to the block, bores, or pistons. If I get poor compression results again I’ll look at correcting the cam timing. Can this simply be done by marking the cam, loosening the belt, and turning the cam counterclockwise (when looking at it from the front of the engine) or do I need to line everything up to TDC again? I really wish they had those adjustable pulleys in stock when I did this build…

[Pescado]

Yes, 110 is way low, like "time to rebuild the engine low"... I agree with Nut's suggestions.

But I'm also curious about the hissing sound. Vacuum leak? Can you recreate the sound in the driveway with the hood open by just revving the engine? Is the sound continuous or does it come and go, or pulsate?

-Bryan

Hey Bryan the sound occurs every time the throttle is moved be it by hand or by foot and only when its moved.

[Nut124]

110psig, eh? Was the throttle open or closed when cranking for this test? Needs to be open.

Was anything done to the block, bores, pistons? If not, it is likely your intake cam timing is way retarded, like one full tooth.

I’m not sure that I had the throttle pressed down…I’ll do the test again. No mods to the block, bores, or pistons. If I get poor compression results again I’ll look at correcting the cam timing. Can this simply be done by marking the cam, loosening the belt, and turning the cam counterclockwise (when looking at it from the front of the engine) or do I need to line everything up to TDC again? I really wish they had those adjustable pulleys in stock when I did this build…

We would want to advance the intake cam timing, so that valves open/close earlier. My brain tells me we'd need to loosen belt and turn the cam clockwise, looking from front. You do not have to be at TDC to do just that but around TDC is where the cams like to stay put. Elsewhere, they want to turn. Regardless, I'd use paint to mark the cam pulleys and belt so this current position would be known when adjusting.

[Pescado]

110psig, eh? Was the throttle open or closed when cranking for this test? Needs to be open.

Was anything done to the block, bores, pistons? If not, it is likely your intake cam timing is way retarded, like one full tooth.

I’m not sure that I had the throttle pressed down…I’ll do the test again. No mods to the block, bores, or pistons. If I get poor compression results again I’ll look at correcting the cam timing. Can this simply be done by marking the cam, loosening the belt, and turning the cam counterclockwise (when looking at it from the front of the engine) or do I need to line everything up to TDC again? I really wish they had those adjustable pulleys in stock when I did this build…

We would want to advance the intake cam timing, so that valves open/close earlier. My brain tells me we'd need to loosen belt and turn the cam clockwise, looking from front. You do not have to be at TDC to do just that but around TDC is where the cams like to stay put. Elsewhere, they want to turn. Regardless, I'd use paint to mark the cam pulleys and belt so this current position would be known when adjusting.

Ok that makes sense…just did the test again and got starting from cylinder #1….125,130,120,120

[18Fiatsandcounting]

[Hey Bryan the sound occurs every time the throttle is moved be it by hand or by foot and only when its moved.

It's not normal intake noise is it? That sounds more like a sucking sound, but it's usually pretty faint if the air cleaner is installed.

As for the compression, well, those numbers are better but still not great. How does the car drive? If it seems peppy enough, I'd probably leave it alone, once you have verified Nut's suggestion about the cam timing.

-Bryan

[Nut124]

Ok that makes sense…just did the test again and got starting from cylinder #1….125,130,120,120

Those numbers are in the low normal range. Cam timing may not be the cause here.