Spica question about BC switch (newbie) - Alfa Romeo Bulletin Board & Forums
 2Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 18 (permalink) Old 09-19-2019, 05:26 AM Thread Starter
Registered User
 
bfeng's Avatar
 
Join Date: Feb 2011
Location: Boston Massachusetts
Posts: 198
Garage
Spica question about BC switch (newbie)

Iíve read thru several writeups as I go thru the Spica system on a new-to-me 1974 GTV.

My motivation is incorrect cold start behavior (no fast idle), and slight popping on decel. Other than this car drives nicely.

The Spica and ignition system had a comprehensive tuneup by a vintage Alfa specialist less than a thousand miles ago (with PO). The repair write up indicates a nearly dead TA.

With Alfa club Spica writeup in hand, I removed the Shankle air cleaner assembly to have a look.

First thing: I noticed there is no lever on the barometric compensator (thingy above the TA). All thatís there is a protruding shaft with two flats. Could this be correct for a 1974 USA GTV?

Second, there is no 12VDC seen at the FCS as the engine rpm comes down. Itís the nicroswitch, right?

Iím going to fix these things without sending the pump to IE for a full on rebuild.

Thanks for all feedback.

John

John F.
bfeng is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old 09-19-2019, 06:48 AM
Registered User
 
divotandtralee's Avatar
 
Join Date: Nov 2005
Location: Cape Cod, MAssachusetts
Posts: 7,287
John, perhaps the most frustrating part of the SPICA is the diagnosis of issues from where I have been. It's not a 1,2,3 like carbs. An "almost" dead T/A is kind of like almost having an almost head ache..or almost heart attack. The Average Seasonal Compensator lever (a mouth full) missing tells me the tech just blew it off as not important. I guess he thought the decel issues weren't either. Start from scratch by changing the two fuel filters for starters and the T/A. Then open up the rear filter open to see how much crap is inside. That done then try to diagnose the results. I truly believe that most Spicas on the road with qualified regular maintenance have some sort of issues that are lived with and the techs know better than to use hours and hours of time ($$$$ not recovered) going after the fix. They know these are low-use cars and just pass them out the door and tell the owner not to worry. Don't forget the Spica is almost 50 years old in these cars.
divotandtralee is online now  
post #3 of 18 (permalink) Old 09-19-2019, 07:41 AM Thread Starter
Registered User
 
bfeng's Avatar
 
Join Date: Feb 2011
Location: Boston Massachusetts
Posts: 198
Garage
Fuel and spica filters changed 1000miles ago.
I agree that most owners won’t invest in fixing the Spica if the car drives well.

I wonder if R&R of the internal Microswitch for the FCS is a DIY job. I think I can live with the non op TA if I hook up the hand throttle (cable has been cut at the firewall). Any pics on how it should be routed and connected to the throttle throttle linkage?

Seems to be the things where you really want Wes are fixing the leaky plungers , and optimizing fuel delivery for a souped up motor.

John

John F.
bfeng is offline  
Sponsored Links
Advertisement
 
post #4 of 18 (permalink) Old 09-19-2019, 09:17 AM
Senior Member
Gold Subscriber
 
Join Date: Oct 2018
Location: Cranbrook, BC, Canada
Posts: 271
Garage
Hi there, even with only a 1000 miles, with an unknown car I would still change the rear filter and open it up. The filter is cheap as dirt at napa, only takes a few minutes to change, the longest time spent jacking the car up, not too messy if you pinch off the inlet hose with something. I think 74 would still have the old style front filter housing, if that's the case then the rear filter is doing all the filtering for the whole system as the rear napa filter is 10 micron and the front element is 38 micron.... The next gen front filter is 4 micron.
Tuning around a bad TA is a slippery slope, better to change the TA, get a sure start or build a dummy TA and leave it in.

R&R of the microswitch is DIY if you consider a R&R of the Spica pump DIY. Is there power to the microswitch? When doing the test did you rev it up enough and snap the throttle off?

Setting up Spica isn't hard but it really is a front to back process that needs to be followed from front to back and not piece meal.

From memory some T number spica pump don't have a leaver on the top, what is your currently installed T number of pump?

Cheers,

Carson, 4 Alfa's, 9 Cars, 4 Motorcycles
vintagemilano is offline  
post #5 of 18 (permalink) Old 09-19-2019, 09:27 AM
Registered User
 
divotandtralee's Avatar
 
Join Date: Nov 2005
Location: Cape Cod, MAssachusetts
Posts: 7,287
Quote:
Originally Posted by vintagemilano View Post
hi there, even with only a 1000 miles, with an unknown car i would still change the rear filter and open it up. The filter is cheap as dirt at napa, only takes a few minutes to change, the longest time spent jacking the car up, not too messy if you pinch off the inlet hose with something. I think 74 would still have the old style front filter housing, if that's the case then the rear filter is doing all the filtering for the whole system as the rear napa filter is 10 micron and the front element is 38 micron.... The next gen front filter is 4 micron.
Tuning around a bad ta is a slippery slope, better to change the ta, get a sure start or build a dummy ta and leave it in.

R&r of the microswitch is diy if you consider a r&r of the spica pump diy. Is there power to the microswitch? When doing the test did you rev it up enough and snap the throttle off?

Setting up spica isn't hard but it really is a front to back process that needs to be followed from front to back and not piece meal.

From memory some t number spica pump don't have a leaver on the top, what is your currently installed t number of pump?

Cheers,
right on target!!!
divotandtralee is online now  
post #6 of 18 (permalink) Old 09-19-2019, 09:42 AM
Registered User
 
divotandtralee's Avatar
 
Join Date: Nov 2005
Location: Cape Cod, MAssachusetts
Posts: 7,287
Quote:
Originally Posted by bfeng View Post
Fuel and spica filters changed 1000miles ago.
I agree that most owners won’t invest in fixing the Spica if the car drives well.

I wonder if R&R of the internal Microswitch for the FCS is a DIY job. I think I can live with the non op TA if I hook up the hand throttle (cable has been cut at the firewall). Any pics on how it should be routed and connected to the throttle throttle linkage?

Seems to be the things where you really want Wes are fixing the leaky plungers , and optimizing fuel delivery for a souped up motor.

John
It's not so much owners living with it.. It takes a shop a good piece of time to even diagnose the issues.. and they have been down that road so many times and when the estimate runs into the thousands and the customer balks they wasted their time. We talked about gas in the oil. That pretty much made my decision to get a rebuilt pump easy. Everything I've read on the micro switch is a tear down of the pump, according to Wes. It sounds like the T/A and fiilter in rear is a starting point, like we said . The manual throttle is not for setting your idle. There are a couple places to set the idle , including throttle opening in synch , air mixture at the top of the manifold, and throttle stop screw on the right of the firewall. The MT can be thrown away and never be lost in the mix if the SPICA had a brain. Mine is disconnected and now broken and I'll miss it for warm-ups in winter but that is all. It has no bearing on tuning a SPICA.

Last edited by divotandtralee; 09-19-2019 at 09:45 AM.
divotandtralee is online now  
post #7 of 18 (permalink) Old 09-19-2019, 10:01 AM Thread Starter
Registered User
 
bfeng's Avatar
 
Join Date: Feb 2011
Location: Boston Massachusetts
Posts: 198
Garage
Very helpful feedback.
Most of this sounds like stuff I can do.
Paul Glynn is a friend and not far, and I’m not opposed to paying him to work on the car. But I take perverse pleasure in spending 3x more of my free time before appealing to paid experts.

John

John F.
bfeng is offline  
post #8 of 18 (permalink) Old 09-19-2019, 10:14 AM
Registered User
 
goats's Avatar
 
Join Date: Jul 2006
Location: san diego CA
Posts: 5,201
read the sticky from ROadtrip at the top of this forum. It explains step by step what to do. I agree, when an owner gets the news 'well the TA is bad and the pump is leaking gas into the oil, parts will be $1900 and labor is another 600' the urge to put carbs on becomes almost overwhelming

74 GTV with 10548's and Ingram pump
71 Spider 1750 BOMBER ; 1995 LS 78K tight fast car
goats is online now  
post #9 of 18 (permalink) Old 09-19-2019, 10:38 AM Thread Starter
Registered User
 
bfeng's Avatar
 
Join Date: Feb 2011
Location: Boston Massachusetts
Posts: 198
Garage
Goats
I did read the sticky. Very helpful.
$1900....

I consider fixing the Spica just another part of restoring the car. If your engine needed a rebuild, many of us would just grit our teeth and do it rather than source a know good used an engine from another car. If your seats needed recovering, not everyone would throw in a set of golf GTI seats.

There is philosophical, financial, and functional benefit for keeping it the way the designers intended. I do not feel this way about DOT required modification like side marker delete and ride height changes..

John

John F.
bfeng is offline  
post #10 of 18 (permalink) Old 09-19-2019, 10:42 AM
Registered User
 
goats's Avatar
 
Join Date: Jul 2006
Location: san diego CA
Posts: 5,201
oh yeah john I agree. Both my cars are SPICA still. But I do have a carb conversion kit that will likely make its way onto one of them if and when the SPICA wears out. A well tuned SPICA car is a joy and no performance loss over carbs either the way I drive. On the other hand, all Euro cars from the era had carbs.....so technically either way is 'correct' to my way of thinking --

If you are keeping Spica, its worth it to get a copy of Wes' Spica manual.

74 GTV with 10548's and Ingram pump
71 Spider 1750 BOMBER ; 1995 LS 78K tight fast car
goats is online now  
post #11 of 18 (permalink) Old 09-19-2019, 11:16 AM
Registered User
 
divotandtralee's Avatar
 
Join Date: Nov 2005
Location: Cape Cod, MAssachusetts
Posts: 7,287
Quote:
Originally Posted by bfeng View Post
Goats
I did read the sticky. Very helpful.
$1900....

I consider fixing the Spica just another part of restoring the car. If your engine needed a rebuild, many of us would just grit our teeth and do it rather than source a know good used an engine from another car. If your seats needed recovering, not everyone would throw in a set of golf GTI seats.

There is philosophical, financial, and functional benefit for keeping it the way the designers intended. I do not feel this way about DOT required modification like side marker delete and ride height changes..

John
FWIW. The Wes package is a tad higher-- Pump+ base+ pulley $1125.. Gaskets /special tool/seals O-rings/plating $200... Injectors $300.. Filters $44 ...Shipping $35 ...T/A $385 = Net counting cores (PUMP +TA+injectors) $2089. I paid Accel Automotive $840 (7hours x $120/hr)and 1 hour for injectors = $920 with tax. So my total job was $3009. The installation was worth every penny as they removed and installed and tuned everything and road tested on the new pump. In the end it was all worth it. A carb conversion has to be more than 2 grand when all is said and done with your own labor so I don't believe there is much saved in the long run to just chuck the pump and do the carbs. It's not as simple as changing your underwear. Chasing after linkages, air filters, carbs and possibly another manifold and carbs isn't fun IMHO. I'm just saying a failed pump is no reason not to fix it and the car has retained it's pedigree and intrinsic value by keeping it..Ii haven't seen resale on carb converted cars make t worth it., either. There are more purists who want the original equipment especially if it has been refreshed or runs properly.
divotandtralee is online now  
post #12 of 18 (permalink) Old 09-19-2019, 12:07 PM
Registered User
 
goats's Avatar
 
Join Date: Jul 2006
Location: san diego CA
Posts: 5,201
Agree. The 'hot street' motor I am currently building will be Spica HP from Wes, RIchard J cams, motronic pistons, bored out throttle bodies and mild head porting, with 1mm oversize intake and exhaust valves. This motor came from a Lemons car Wes Conklin and I'm finally getting around to adding the fuel, cams, intake etc. Should be pretty fun I hope!

When its dialed in, Spica is trouble free and a joy to drive.

74 GTV with 10548's and Ingram pump
71 Spider 1750 BOMBER ; 1995 LS 78K tight fast car
goats is online now  
post #13 of 18 (permalink) Old 09-19-2019, 12:29 PM Thread Starter
Registered User
 
bfeng's Avatar
 
Join Date: Feb 2011
Location: Boston Massachusetts
Posts: 198
Garage
Quote:
Originally Posted by vintagemilano View Post
R&R of the microswitch is DIY if you consider a R&R of the Spica pump DIY. Is there power to the microswitch? When doing the test did you rev it up enough and snap the throttle off?

Setting up Spica isn't hard but it really is a front to back process that needs to be followed from front to back and not piece meal.

From memory some T number spica pump don't have a leaver on the top, what is your currently installed T number of pump?

Cheers,
Can't be any more difficult to R&R than a whole motor or transmission.

I assume the number type of the pump is on one of the side tags. I'll get in there with a mirror tonight to see what the tags say. But I suspect the adjustment lever is simply missing due to some previous mechanic.

I'll check for 12VDC at the microswitch tonight (have to jack the car up and come at it from underneath.

John
goats likes this.

John F.
bfeng is offline  
post #14 of 18 (permalink) Old 09-19-2019, 07:52 PM
Senior Member
Gold Subscriber
 
Join Date: Oct 2018
Location: Cranbrook, BC, Canada
Posts: 271
Garage
Nope, there are two wires to the microswitch, one is in, one is out, out goes to the fuel cutoff solenoid. I think both are white, comes from Fuse 6. There is probably a spade connector (or maybe bullet) somewhere in the wiring under the air filter canister.

Cheers,

Carson, 4 Alfa's, 9 Cars, 4 Motorcycles
vintagemilano is offline  
post #15 of 18 (permalink) Old 09-20-2019, 08:22 AM
Senior Member
Platinum Subscriber
 
Roadtrip's Avatar
 
Join Date: Jan 2003
Location: Rapid City SD, Black Hills of South Dakota
Posts: 9,937
1. If your car is a 1974 model and does not have the temperature compensator lever on the top of the Barometric Compensator, then it's likely the injection pump has been replaced with one from a later model.

2. The Fuel Cutoff Solenoid (FCS) is powered by the #6 fuse. Check to make sure that's good. If so, there is a white wire on the right side of the engine compartment wheel well with a spade connector. The the key switch ON, check that there is 12v there. If so, then chase the wire to the microswitch. Those wires to the microswitch live a tough life with heat, vibration, and oil seepage. If indeed the microswitch is bad, then you'll have to remove the pump to change it. Changing the switch and adjusting it once the injection pump is on the bench is easy and cheap if you can solder.
Attached Images
 

John Stewart
74 Spider
91 164S
Roadtrip is online now  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome