Timing Belt Guide for a 1.8

[18Fiatsandcounting]

That was a good rant, Steiny. Maybe even worth repeating!!

-Bryan

[18Fiatsandcounting]

OK, back to seriousness. In your YouTube video, where were you spraying? Intake manifold around cylinder #1, an emission control part, or ??

Sure does look / sound like you have a vacuum leak.

-Bryan

[SteinOnkel]

Intake manifold around cylinder #1.

This has got to be the issue. You spray it, it revs waaaaay high...which means if you plug the leak, you can rotate the dizzy to something more sensible

And boy oh boy does it idle great when all four cylinders are firing.

[18Fiatsandcounting]

When you pull off the intake manifold, I'd take it to a machine shop and see if they can machine the mating surface flat and with a good surface finish for the new gasket. Clean up the mating surface on the cylinder head, and see if you can get a straight edge in there to make sure it isn't warped somehow. I've never seen this, but that doesn't mean it can't happen.

I'm guessing you know all this, but just thought I'd toss it out there.

-Bryan

[SteinOnkel]

Ahoi hoi!

Success! To confirm my diagnosis, I gooped some rtv grey sealant around the suspected leak area (I know, I know). The idle is so much better now. Adjusted the timing to 10* BTDC at idle and set the speed to exactly 850 rpm. Adjusting the mixture and speed took all of two minutes, because the engine is now one happy camper. And it doesn't diesel on shutdown anymore either, so I don't need a replacement idle solenoid after all.

It's not 100% perfect yet, one of the cylinders still intermittently misfires at idle, but it is hand over fist better than it was.

I will be replacing the intake manifold gasket again during the next week. I'll be using a different vendor this time and will use a straight edge and feeler gauges as Bryan suggested to look for potential warpage.

Once that is all done, I'll be tackling the broken thread in the exhaust manifold. It leaks like a sieve. Which is very bad, because I can't drive the car with the top up due to exhaust fumes making their way into the cabin. I will try to fix it inside the engine bay. I think I can fit my drill in there, we shall see.

Cheers
Steiny

[18Fiatsandcounting]

....Once that is all done, I'll be tackling the broken thread in the exhaust manifold. It leaks like a sieve. Which is very bad, because I can't drive the car with the top up due to exhaust fumes making their way into the cabin.

Steiny, which one of the 5 exhaust flange bolts is the problem? Broken bolt, stripped threads in the cylinder head, or ??? Can you tell which one of the 4 exhaust ports is the one that's leaking? I'd also suggest checking the flatness of the exhaust manifold flange and cylinder head mating surfaces while you've got it apart.

-Bryan

[SteinOnkel]

If you're standing next to the car looking over the engine with the exhaust manifold in front of you, it's the second from the right. The fastener has very little to grab onto, because the thread in the head is roached.

You wanna know why? Guesssss what! Fiat "guru" grabbed some SAE fasteners from the junk bin once again. Thanks buddy!

There's also one holding the exhaust that is an SAE bolt with four notches cut into its thread. It basically cuts its own thread. Very odd, but that one does actually hold.

Never mind that it's all supposed to be studs + self locking copper nuts. But those cost money...

[SteinOnkel]

Replaced the intake gasket. Car is back to idling horribly.

What the f....

I'll be picking up a propane torch to check for vacuum leaks. The carb cleaner sprays everywhere (of course I lost the little red straw) and I don't know if it's idling higher because it sucks in through the carb or it's actually leaking.

Man I should have just left it alone with the gooped on silicone. Ugh.

[18Fiatsandcounting]

Steiny, you're killin' me....

So, when you sprayed the carb cleaner around cylinder #1 and the idle speed increased, what else is in that area other than the intake manifold? An emission control component?

When you sprayed the carb cleaner, you're plugging up some sort of vacuum leak. If not the intake manifold, what else?

-Bryan

[SteinOnkel]

Bryan, it's the car that's killing us

So today I used a propane torch to narrow down the leak. It is not the intake manifold. Thank goodness, that thing is a bear to get in and out of there.

It seems to be the carb base. I suspect that carb cleaner, which has a tendency to go everywhere just got into the intake at another leak. No emissions equipment is left, that's all plugged, welded shut etc.

When I bought a rebuilt kit many moons ago, it came with gasket underneath the carburetor, but the quality was sub-par. It was compressed layers of paper or something or the other. According to the vendors it's supposed to be two gaskets and a bakelite spacer?

Anyways I took the carb off, that gasket is already pretty beat up. Used Mr. Silicone, it helped a little but not much. Still leaking on the left side. So I ordered the two gaskets and bakelite spacer., it just kind of flakes apart. I'll report back when the new stuff is installed.

So close now, so tantalizingly close to a great idle...

Cheers
Steiny

[18Fiatsandcounting]

So today I used a propane torch to narrow down the leak.

Some people might choose oxy-acetylene, cranked up on high... 2000 degrees fixes many problems.

So close now, so tantalizingly close to a great idle...

I'm patiently waiting. Come on down to Livermore when you get that idle! I'll offer you a beer!

-Bryan

[manoa matt]

You can flatten manifold mating surfaces by using spray adhesive and abrasive paper on a flat plate. Table saw top, thick glass, granite slab, or new un-warped particle board/MDF. When I got a stainless header, the mating flange was not true. Looked around for woodshops that would have a nice big belt sander large enough for the flange, but nobody was willing to let me flatten the flange. I ended up buying a 100 grit abrasive belt for a belt sander, cut it and glued it to a flat board. Marked the flange with permeant marker and stropped it back and forth until it was flat.

For something like the carb mating flange on the intake manifold you can remove the carb, remove the studs and stuff the hole with rags. A flat sharpening stone or flat bastard file will work since the mating flange is not that big. Vacume out the aluminum dust before and after removing the rags.

You are correct, the original spacer between the carb and manifold was 1/4" thick bakelite with brown paper gaskets on either side. There is a second thick paper spacer between the main carb body and the lower throttle plate section. It's very common for the "ears" of the carb main body to become warped downward from overtightening the hold down nuts. The thick paper gasket is absolutly needed between these two carb pieces as it will take up any inconsistencies. As for the lower thick paper gasket that comes with the rebuild kit intended to go between the carb and manifold, I suspect it is supplied as the original bakelite gaskets are NLA and after 40 plus years won't seal as well as the thick paper version that can compress.

[SteinOnkel]

You are correct, the original spacer between the carb and manifold was 1/4" thick bakelite with brown paper gaskets on either side. There is a second thick paper spacer between the main carb body and the lower throttle plate section. It's very common for the "ears" of the carb main body to become warped downward from overtightening the hold down nuts. The thick paper gasket is absolutly needed between these two carb pieces as it will take up any inconsistencies. As for the lower thick paper gasket that comes with the rebuild kit intended to go between the carb and manifold, I suspect it is supplied as the original bakelite gaskets are NLA and after 40 plus years won't seal as well as the thick paper version that can compress.

Wait hang on.

My setup is like this: manifold, then paper gasket thingy (about 1/4" thick), throttle body, thin paper gasket, bakelite (with three holes in it for vacuum ports in the top carb housing etc), second thin paper gasket, carb middle portion.

That paper thing came with a carb rebuilt kit. I figured it was for underneath the carburetor. I guess not, whoops.

[SteinOnkel]

So today I used a propane torch to narrow down the leak.

Some people might choose oxy-acetylene, cranked up on high... 2000 degrees fixes many problems.

So close now, so tantalizingly close to a great idle...

I'm patiently waiting. Come on down to Livermore when you get that idle! I'll offer you a beer!

-Bryan

Aluminum pieces tend to seal up quite well when they are molten!

I'll take you up on that offer soon. My parents are moving from Livermore to Sacramento soon and I can't quite shake the feeling that I'm going to be roped into it somehow hmm.

[manoa matt]

Well, I went to check and here is what I got. One 34ADF on the car and two 32ADFA parts carbs. All three of my carbs have the thick paper gasket between the upper body and the throttle section. The 34 ADF on the car has a thin paper gasket between the throttle section and the intake manifold.

However, in the box of spare carb parts and gaskets, I have 2 of the phenolic spacers and 2 of the paper gaskets. All of them have 6 smaller holes indicating they are intended to go between the upper body and the throttle section. Both of the parts carbs have warping issues. The upper body flange is visibly warped and there are gaps between the upper body section and the paper gasket. If a phenolic gasket is used in that interface, it would be more likely to produce a vacume leak, vs the paper gasket that will compress and seal. Let me know if you want me to send you one of the thick paper gaskets. send me an email and I can drop it in the mail, also photos of the warping condition. matt.scarton@gmail.com

Interesting that your phenolic spacer has three holes in lieu of 6. If you turn the carb upside down, you will see three holes on the bottom surface of the throttle section, however they have side channels that run into the throttle bore. The bottom gasket that goes between the carb and manifold is typically thin with one big oval hole.