78' FI Smoke Test - leaking intake manifold gasket or FI gasket?

[BoltonFTW]

Performed my first smoke test on '78 Westy with FI yesterday (with much help from reading through these forums, tyvm) and could use some additional help verifying a leak. A few extra trained eyeballs on this would be great.

I was getting some smoke leaking near the #4 injector which makes sense because my plug in that cylinder that I previous checked shows that it has been running lean.

I apologize for this somewhat crappy video of it in action but was hoping extra eyes could help me identify if it looks like an intake gasket or injector seal (just replaced my FI lines recently- the injector seals looked fine and according to my records of the vehicle they were replaced about 3k mi ago. So I am leaning toward the intake manifold gasket. But again having no frame or reference I am making an educated guess. It could even be something else entirely?

Video link:
https://photos.app.goo.gl/PZU9a2snLSkptUw5A

Disclaimers:
-78 FI GE engine code
-yes that audio is my air compressor running
-extra smoke towards opposite side of engine bay is just from my poor job of sealing up the S boot and it starting to leak out through the tape.

So yeah extra eyes appreciated! it kind of looked like it was coming from below the intake manifold gasket but I couldn't quite get my camera all the way under.
Thanks
_________________
Drew
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1978 Westfalia Campmobile Deluxe 2.0 FI w/hydraulic lifters
1977 Westfalia Weekender Tintop (very first car - SOLD )
1992 VW Corrado VR6 (SOLD)

[airschooled]

Hey Drew,

I think you’re on the right track. When was the last time the 13mm M8 intake manifold nuts were snugged up? I’ve started checking them at every valve adjustment, and they usually need a little tightening. Another common problem is the tin getting stuck under the manifold. Can you push the tin with a screwdriver or something to make sure it wiggles all the way around the manifold?

Do you see any smoke under the car, from various exhaust joints or cylinder spigots?
Robbie
_________________
Learn how your vintage VW works. And why it doesn't!
One-on-one tech help for your Volkswagen:
www.airschooled.com

[BoltonFTW]

Robbie,

Thanks for your quick response.

I have no idea last time those nuts were snugged up so I will check that today. Bentley says 14ft-lbs on those.

I will check the tin also at the same time.

I don't remember seeing any smoke coming out from below the engine but I will likely smoke test again after checking the above.

I'm not exactly sure what a cylinder 'spigot' looks like- would i need to remove the tin underneath the engine on that side to see it?
_________________
Drew
---------------------------------------------------------
1978 Westfalia Campmobile Deluxe 2.0 FI w/hydraulic lifters
1977 Westfalia Weekender Tintop (very first car - SOLD )
1992 VW Corrado VR6 (SOLD)

[airschooled]

The spigot is where the cylinder goes into the head

Get your torque wrench on one of the easily accessible manifold nuts on the left side, then remember that feeling for the other bolts because getting the torque wrench in on the right side isn’t worth if if you can recreate the feeling yourself consistently. Remember that shorter ratchets give less torque, so grab your torque wrench in the spot that matches the length of your preferred ratchet.

Torque wrench 102 also dictates that clock-type wrenches are only accurate when the fastener is moving, you should always brace socket extensions with equal force, and you should always hold the wrench in the click/dial indicated position once you reach it to give the fastener a chance to tell you if it strips. (Torque will drop off in that case.) Always store click-type wrenches at their lowest setting too.

Robbie
_________________
Learn how your vintage VW works. And why it doesn't!
One-on-one tech help for your Volkswagen:
www.airschooled.com

[gintaras]

Are you missing your TSII (Temp Sensor)?
There is a threaded hole next to the intake with a big circle cut out of the tin.
_________________
1979 Deluxe Westy in Mexico Beige

[Wildthings]

The easiest and cheapest job is to replace the injector seals, so you might want to start there.

[BoltonFTW]

[BoltonFTW]

[BoltonFTW]

[SGKent]

replace the gasket and phenolic block between the cylinder head and intake runner.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Wildthings]

[airschooled]

Excellent technique blowing the smoke away towards the end of the test. You can see the smoking gun out of the #4 manifold gasket. On new gaskets/spacers, it's USUALLY one spacer block with a thin gasket on each side. I have seen some off-brands that are separate gasket/spacer/gasket style, but they are rare. The gasket is so thin that the surfaces need to be very clean. Lucky for you, any debris ingested by the engine is Major Danger. Since you'll have the injectors off, now is a perfect time to reset the service clock on those injector seals… How are your fuel lines? TS2 fully seated? Engine grounds clean and snug? All SORTS of projects to do while you're in there!

Discussion question:
Do YOU think the low compression and vacuum leak on cylinder #4 are related? Why, or why not?

See you on the road,
Robbie
_________________
Learn how your vintage VW works. And why it doesn't!
One-on-one tech help for your Volkswagen:
www.airschooled.com

[BoltonFTW]

Thanks for all the feedback and responses- I appreciate it as I continue to learn about this engine.

I've gone ahead and ordered the block/gaskets and will be replacing them. From the bentley it looks like I don't even have to remove the intake plenum. I can just pull injectors and then the intake manifold?

I will do the injector seals at the same time and check the FI grounds.

I've already done the fuel lines and my TS2 is snugged up fine with the copper washer.

For the manifold gasket installation: I read through some other threads and people have mixed thoughts on installing dry vs. using a gasket sealant? Any additional thoughts on that?

As for the compression discussion question:
I was originally thinking that the leak at the manifold would cause a direct relation to the lower compression but I re-thought it and realized that the compression test checks the compression within the cylinder with all valves closed on the compression stroke. Sooo likely this leak does not directly affect the compression in that cylinder (i.e. fixing the leak will not raise the compression)-- but as Wildthings mentioned if this leak has been around a while it could have caused extra wear (running lean/hot) to piston ring or valve seats that would indeed affect compression in that cylinder.(?)
_________________
Drew
---------------------------------------------------------
1978 Westfalia Campmobile Deluxe 2.0 FI w/hydraulic lifters
1977 Westfalia Weekender Tintop (very first car - SOLD )
1992 VW Corrado VR6 (SOLD)

[Wildthings]

If you don't know how old the boots are between the plenum and the manifold runners, now might be the time to renew them as well.

[airschooled]

[BoltonFTW]

[oshima]

[BoltonFTW]

Is it okay to reuse the intake runner sleeves? Mine have less than 3000 miles on them and were installed in 4/2017. Then again so was the gasket I'm about to replace.
_________________
Drew
---------------------------------------------------------
1978 Westfalia Campmobile Deluxe 2.0 FI w/hydraulic lifters
1977 Westfalia Weekender Tintop (very first car - SOLD )
1992 VW Corrado VR6 (SOLD)

[Wildthings]

[BoltonFTW]