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Discussion Starter #1 (Edited)
87 Quad (L-Jet with electronic solenoid vvt)

I've been fiddling with my camshaft timing, and after making a change (returned the intake to an earlier retarded position - don't ask), and getting everything back together and hooking everything up, I went test the vvt. Instead of my usual method of key "on", and lifting the throttle rod, which only confirms the solenoid activates and pushes the plunger inside the cam cover, I decided to run the engine and use a small screwdriver to push the plunger which should cause the engine to run extremely rough. It didn't run rough. Tried this over and over again and nothing.

The issue is not solenoid related (has power, is properly gapped, triggers around 3/4 throttle, pushes the plunger in, and retracts itself freely). I can also confirm the button on the front face of the intake cam that the plunger pushes against, goes in and retracts itself fine.

As I mentioned earlier, previous tests of the vvt only involved the triggering of the vvt solenoid with the car off, so I don't know if the problem is new or long-standing. But what I can say, is with the cam in that or about that retarded setting (done by PO), the vvt fuse was removed and when I installed the fuse, the vvt mechanicals got stuck and the car idled horribly until something in the internals fine unstuck itself. So the vvt guts did kinda work back when I bought the car.

So I'm wondering what is supposed to happen inside the vvt when that button is pushed in, preferably in layman terms. Additionally what alternate test method there is. PM'g with a member, there was mention of an air pressure test. Can anybody elaborate?

I've run out of time today to return the cam back to factory settings to see if the retarding of it has affected the vvt functionality, but for now I'm looking for any insight on this possibility, and alternate test methodology.

Thanks,
Mike
 

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In the photo below (stolen from this thread) you can see the oil passage in the cam bearing area of the lower camshaft pictured (the other cam has the same hole but not visible in the photo). Remove the cam cap closest to the VVT, turn the engine until that oil passage is accessable. With a rubber tip on your blow gun, apply 50-60 psi air pressure. When you push in the trigger thingy on the end of the VVT (or move the weight of the centrifugal VVT) the camshaft should move a few degrees (which will probably knock your blow gun out of position...).

 

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Now, having said (written) all that, I haven't tested the VVT that exact way. I've done it with the camshaft out of the car, holding the camshaft and watching the VVT move. Which makes me wonder if what I wrote will actually work...?
 

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Discussion Starter #5
Now, having said (written) all that, I haven't tested the VVT that exact way. I've done it with the camshaft out of the car, holding the camshaft and watching the VVT move. Which makes me wonder if what I wrote will actually work...?
That is promising, because I just tried with the cam still in the car and it didn't budge. I have also repositioned the cam back to the factory mark, will button it all up and retry my test to see if I can get the idle to go all lumpy.
 

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Discussion Starter #7 (Edited)
That was quite the read and to be honest I got lost in it.
Looks like I may need a new one also.
As stated above, I tried the air trick but didn't know about needing to push in the button.
With everything back together, I tested the vvt again by manually moving the plunger and the idle did not get lumpy.

In that thread, there was talk about seals. Is my vvt able to be rebuilt, instead of running the risk of getting another non-functioning one.
 

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Discussion Starter #8
I studied the shop manual pages about the vvt assembly and operation. From what I gather, when I did the air test and didn't push in the button, the cam would not have advanced (which it didn't), but the air I injected into the hole should have relieved itself out the button, which it did not. It seems that a part in the assembly is either worn/broken/jammed, an area is clogged, and/or a seal(s) are shot.

What I don't know is if there is any benefit or consequence in injecting higher air pressure in the hole in hopes of clearing a possible blockage. Anyone?

I found the following thread where somebody has taken the vvt apart, so it can be rebuilt providing all it needs is a good cleaning and perhaps new seals. In typical Alfa fashion, the manual calls for some special tools!

http://www.alfabb.com/bb/forums/spider-1966-up/183825-how-cancel-vvt.html
 

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Discussion Starter #9
The cam cover is off and I've blasted the hole with air again.
This time I can hear air escaping, but not just thru the front button.
I even feel it coming out from the drain hole in the body of the vvt, which means the seal has failed. But I can also hear what I guess is the inner splined gear knock suggesting its free to operate as it should, just not enough to advance the camshaft due to the insufficient pressure build up because of the seal failure.

Making progress!

I wonder how many others have a similar issue with their vvt, and suspect as I always did, that their vvt is fine based on the solenoid plunger activation test only.
 

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Discussion Starter #10
Took the cam out of the car tonight and disassembled the vvt.
I will post pics of it all apart when I get a chance, as somebody may benefit from them one day.
The seals (which are actually piston rings) seem okay.
All the parts themselves seem okay.
What I'm hoping was my problem is the fairly plugged up inlet port on the camshaft. (10 mins with dental pics, and a paper clip)
I hope to reassemble it and test it tomorrow night.
 

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Took the cam out of the car tonight and disassembled the vvt.
I will post pics of it all apart when I get a chance, as somebody may benefit from them one day.
The seals (which are actually piston rings) seem okay.
All the parts themselves seem okay.
What I'm hoping was my problem is the fairly plugged up inlet port on the camshaft. (10 mins with dental pics, and a paper clip)
I hope to reassemble it and test it tomorrow night.
Hi Mike,

I hope you are right about the inlet port being plugged up.

How can you tell if the seals, piston ring looking seals, are good by just looking at them?

Good luck,

Vin
 

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Discussion Starter #12
Although I have never torn an car engine apart, at work we manufacture and service diesel pile drivers, which are essentially a massive 1 cylinder diesel engine, and the piston has a number of piston rings on them. So I have some familiarity with piston rings, and personally inspect them upon receipt.

Other than a required ring width and girth so it sits properly in the required groove, the rings must have a specific free gap (the gap size when the is at ring uncompressed), and closed gap (the gap when the ring is compressed into the bore). A required free gap helps to ensure a certain amount of spring tension against the bore.

The fact that the rings were not collapsed (they expanded when removed from thier bores), means the rings still have some life. How much life is uncertain without knowing the designed free gap of a new ring. When the rings are test fit in their corresponding bores, the ring ends must come close to touching (amount by design – unknown), but not bind which can stress the rings and cause them to break. There is normally a miniscule design closed gap to allow for expansion.

My rings are not knicked, scored, or blue (a sign of excessive heat – not likely in this assembly – I think).

Lastly, its important to make sure the bores are clean and free of excessive scoring, pitting, etc. so a sufficient amount of sealing can be obtained.

As I said, I ended up picking and poking semi solid crap out of the cam inlet hole right were the one diameter reduces to the smaller diameter, before it enters to cross drilled hole leading to the vvt.

Here’s hoping!
 

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Discussion Starter #14
Yes, I took lots of pics. I hope to post them tonight.
Its a really neat device in terms of its design and operation.
They are refered to as seals in the manual, and are metal piston rings.
 

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Out of interest, what makes those of you who test these think they might not be working correctly? Are there particular symptoms associated with a failure?

I haven't a clue whether mine are working properly or not but if there's a chance that a few minutes with a tooth pick could unleash a few extra horses I may just have to investigate!
 

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Discussion Starter #16
All you need to do is appply 12v to the vvt solenoid in the correct manner to activate the plunger (with the car running), and see if the idle gets really lumpy. If it does, the vvt is working. Mine wasn't, but in the past I assumed it was working because I trigger the solenoid with the ran not running and assumed whatever was supposed to be happening inside the engine was, but turns out it was not.

Another way to test with car running, go into the vvt sight hole with a tiny screwdriver and manual advance the plunger. Lumpy, good, stays the same, not working.

Good luck.
 

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Discussion Starter #17
Quick update...
Instead of eating my lunch, I re-assembled the vvt.
And......... I'm starving!!!!
And..........It works!!!!!!
I just need to fully assembly it to torque and with loctite where prescribed by the manual, and its ready to go back into the car, to give me extra little juice I've always felt my car lacked - since buying it 3 years ago.

I'm not expecting night and day performance gains, just what I've felt missing in comparison to others Spiders.

Pics still to come (tonight), and hopefully final results tomorrow night.
 

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glad to hear that Mike...well done (gonna run out tomorrow and check mine with running engine:).....though pretty sure it is working.

.........so if I understood your posts correctly: you found the VVT itself was in fact fine.....but, the oil feed hole in the camshaft itself was blocked, not feeding oil pressure to the VVT to operate it.......or, was there a blockage in the VVT as well?
 

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Discussion Starter #20
Yes, the only issue I found (after complete disassembly and cleaning), was at the bottom of the inlet port, where the port reduces in diameter, just before breaking into the center port of the camshaft. I found this after confirming the seals seemed ok, and no other parts holes were blocked. The last part to check and clean was the shaft. At the bottom of that hole, it felt cruddy (not solid steel), and I couldn't see light when shining a light in one of the holes and looking into the other. At first I could barely get a sewing needle to break thru to the center port, and once cleaned, the hole feels to be about 1/16" in diameter.
 
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