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Discussion Starter #1 (Edited)
I’ve got several writeups on going thru the Spica system on a new-to-me 1974 GTV.

My motivation is incorrect cold start behavior and slight popping on decel. Other than this car drives nicely.

I removed the air cleaner to have a good look.

First thing: I noticed there is no lever or lock nut on the barometric compensator. Could this be correct for a 1974 USA car?

Second I didn’t get any voltage at the FCS terminal when reving the motor and letting rpm come down. That’s likely the cause of the popping.

Third, the TA isnt moving as much as it should, hence the absence of elevated cold start rpm. Car hold idle fine when I start it from cold but it hasn’t been below about 60F yet.

Fourth: CSS actuated when I applied 12VDC, and the car does start easily/instantly as long as I crack the throttle just a tad before I crank it. I think it’s fine.

So, disappointingly, the Spica system has 2 of the 4 most common failures. I should have checked it pre-purchase ... but the car test-drove so nicely I did think I needed to

I havent yet extracted some of the internal oil to do a proper sniff test for gas. I hope it passes this test, but given the other issues I’m assuming the worst.
 

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First thing: I noticed there is no lever or lock nut on the barometric compensator. Could this be correct for a 1974 USA car?

Second I didn’t get any voltage at the FCS terminal when reving the motor and letting rpm come down. That’s likely the cause of the popping.

Third, the TA isnt moving as much as it should, hence the absence of elevated cold start rpm. Car hold idle fine when I start it from cold but it hasn’t been below about 60F yet.

Fourth: CSS actuated when I applied 12VDC, and the car does start easily/instantly as long as I crack the throttle just a tad before I crank it. I think it’s fine

I havent yet extracted some of the internal oil to do a proper sniff test for gas. I hope it passes this test, but given the other issues I’m assuming the worst.
1. It’s not uncommon for the barometric compensator to missing the lever. It would. It would not be correct for a ‘74 as the SPICA FI pump was pretty much the same for the 2000 model year run afaik.
2. If you’re not getting a voltage change at the FCS, it could be a bad micro switch or a bad wire connection between the switch and solenoid. I’d verify that the solenoid works by bench testing it. Keep in mind there are other causes for backfiring, not just a mid-op of the FCS.
3. A bad TA sounds about right if you don’t have a high cold idle speed.
4. Cracking the throttle open to start the engine isn’t uncommon The air idle adjustment design is crude to begin with.
 

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Discussion Starter #3
Ken

I fiddled and tested more:

Spica microswitch has +12VDC, but. Or passing it to the FCS. Yes I understand that a variety of misadjustments can cause the popping.

I’m finding enough hack work on this car that I now assume nothing regarding the correctness of the Spica system of any of the other mechanical systems. I will, unfortunately, be going thru everything bit by bit to get it all fixed the right way and back to proper condition.

The car drives wonderfully, which is perhaps a testament to the robustness of the Spica system.
 

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The later pumps didn't have a lever on the barometric capsule. So I wonder if it's the original pump, or maybe the capsule unit was changed? They do go bad.
Spica is in my experience very forgiving, and will still run with plenty of misadjustments.

Andrew
 

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Discussion Starter #5
Andrew, when I have time I'll look into the Spica more closely into which pump it is. Yes, it could be a newer pump for all I know.

I bought this car because I thought it was by and large an original car with 1 poor repaint and really only a bit of rust in one corner of the front windshield surround. I was under the impression it was mechanically original config and well sorted. Mechanically I'm just a little disappointed, but I think it can all be fixed and put into original and good condition for under $3000. As far as buying and restoring old cars goes, that's not too bad and well below the threshold of buyer's remorse. This will be a great GTV someday...

One great thing about this car ... now that the freshly added oil in the steering box has leaked out, it doesn't leak anywhere. First old car I've owned that doesn't need a drip pan. That is priceless. A local expert told me to put in 1200 weight oil and the old box won't leak. I think I'll try some Penrite non flowing oil, added a bit at a time until all the lighter weight oil has leaked out.
 

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I'll look into the Spica more closely into which pump it is. Yes, it could be a newer pump for all I know.

I think I'll try some Penrite non flowing oil, added a bit at a time until all the lighter weight oil has leaked out.
I believe there are at least two iterations of SPiCA pumps and the way to differentiate them is by serial number...

Penrite or NLGI #00 grease should work fine for your steering box.
 

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The first thing to do is get a rebuilt TA. Very common problem on new-to-me Alfas with spica. Not a big deal. If it's popping on decel from all speeds and there is no voltage from the mico switch but 12 volts going to the micro switch it's probably the micro switch or wiring to the switch. If it isn't popping above 2000 or so rpm on decel and begins popping below that the solenoid may not be working OR the set up is out of wack on the length of the actuating rods, long and short. Most are. If none of that helps there is a vertical positioned spring that can be seen when the Barometric Compensator is removed going from an arm on the bottom to a bolt on the top. On pumps that have never been rebuilt this spring often breaks and throws the mixture way rich. Hope that helps!
 

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The pump will have a tipo number and serial number on the plate. There are a bunch of different types.
Andrew
 

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The first thing to do is get a rebuilt TA. Very common problem on new-to-me Alfas with spica. Not a big deal. If it's popping on decel from all speeds and there is no voltage from the mico switch but 12 volts going to the micro switch it's probably the micro switch or wiring to the switch. If it isn't popping above 2000 or so rpm on decel and begins popping below that the solenoid may not be working OR the set up is out of wack on the length of the actuating rods, long and short. Most are. If none of that helps there is a vertical positioned spring that can be seen when the Barometric Compensator is removed going from an arm on the bottom to a bolt on the top. On pumps that have never been rebuilt this spring often breaks and throws the mixture way rich. Hope that helps!
I’ll second the T/A, it’s not tough to swap, BUT you need small hands and small, deep sockets. And lots of towels to clean up the engine when a gal of coolant runs all over....
 

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I've changed a lot of TAs and it's not a gallon. The level of the TA is high up on the intake manifold and at or above the radiator cap. If one leaves the cap on the amount that comes out is negligible. Also substitute hex head cap screws for the bolts that hold the TA in the pump. Then a long allen wrench with a dab of grease on the cap screw makes it a snap to bolt and unbolt the TA from the pump. The hardest part is getting a 7mm socket on the studs that hold the TA in the head. A quarter inch drive socket will do the trick. I would also recommend you get Wes Ingram's SPICA manual. It's a must and will save you time, money, and most importantly aggravation.
 

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Squeeze the upper radiator hose, open the radiator cap while it's squeezed, reclose cap, create some vacuum, and it won't drip so much. Or drain a little out first.
Keep something over the TA hole in the pump so any spillage doesn't get antifreeze in the pump.

Andrew
 

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The thing about the sure start is getting it hooked up securely to the fast idle on the dash. It takes a lot more force to extend it against the innards of the pump than to merely open the throttle. That being said when it works it works well. I've got one hanging somewhere in my shop I could have used but a good rebuilt TA is hard to beat. There is a thread on building a TA that uses a more dependable actuation mechanism but so far no one has come up with anything plausible. There all sorts of industrial actuators out there and I've searched them but with no joy.
 

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Wes's book will save you $$$, no doubt about it.
 
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