Alfa Romeo Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
37 Posts
Discussion Starter #1
Hello All

My 69 Boat Tail Spider is really difficult to start, Battery turns over ok, but without spraying a bit of petrol directly into the carbs it just wont have it. There is petrol in the float chambers etc. and it will run ok "ish" once going. When it does start there is a definate flat spot when you try to open up the throttle more than a 1/4 way. This gets a little better when it is running for about 10 minutes. What do you think? New Battery, coil? condenser? carb kit? - I have no idea !! help !!!!!
 

·
Registered
Joined
·
3,419 Posts
This sounds like very serious problem.My advice to you is to swop your '69 with my perfect '76 kamm shape :) :D :D.

Have you checked the condition of the sparkplugs and timing?
 

·
Registered
Joined
·
37 Posts
Discussion Starter #3
Thanks Garry, i'll let you know about the swap, yep changed the plugs but not checked the timing, looks like a job for a pro. Think I might get the Weber Man in to do his magic.
 
G

·
Guest
Joined
·
0 Posts
Stupid question, but is the choke pulled out when you are starting ? The 'flat' running you describe is just what happens when you try to open the throttles when engine is still warming up - mixture leans out, and car stumbles / dies. I know my '77 (on Dellorto carbs) likes choke for starting, and comes off the choke after a few minutes. But try and drive it with choke shoved in right after starting, and you can forget it - it just won't have it. Just trying to eliminate the obvious stuff, before we get into the more esoteric stuff...
 

·
Registered
Joined
·
480 Posts
My 69 Boat Tail Spider is really difficult to start, Battery turns over ok, but without spraying a bit of petrol directly into the carbs it just wont have it. There is petrol in the float chambers etc. and it will run ok "ish" once going.
What is your starting procedure? If you have Webers like my '68 - even with the timing correct, a strong spark and a recent carb rebuild it requires a good half dozen or more prods on the accelerator before it will cough into life, and then you have to use the manual accelerator to hold it on a fast idle for a few minutes to warm up. Don't bother with the starting choke, it isn't a proper choke and just doesn't work.

I'd tackle it like this: spark, static timing, basic carb tuning & check for air leaks, dynamic timing, carb balancing and adjusting idle mixture.
 

·
Registered
Joined
·
17,177 Posts
Mine likes a bit of choke if it's clap cold (it's on DellOrtos). Usually give it four good prods on the throttle before starting then catch it on the hand throttle as soon as it fires and stick the choke back in.
 

·
Registered
Joined
·
80 Posts
Are the accelerator pumps all working OK? Had the car been idle for a while before you had this problem?

Hesitance on opening the throttle can be caused by non functioning accelerator pumps, although I would expect that to be the case when the car is warmed through too. (perhaps less so, but still a hesitance)

It would also mean that when you pump the throttle for the without choke starting technique you are not getting the important shots of neat petrol that help starting. (My 1750 round tail starts easily with 3 or 4 pumps, 6 or 8 is too mauch for it)

Has happened to me after fitting some s/hand webers to car which hadn't recently been used.

Fairly easily sorted, but hard to describe without a carb in front of me. Pump the throttle, take the pump jets out, and see if they are dry. Pump again with the jets out and you should be able to see whats happening - fuel squirting out, or a lack of it.

In my case I took the tops of the carbs, took the brass screws out which cover a weight and a ball bearing (have a look at an exploded DCOE diagram and you will se what I mean). Patience, tweezers to remove the weights, and carb cleaner, and a bit of pumping freed them off. I think the ball bearings were stcuk fast with gummed up petrol deposits.

Other options are blocked pump jets, or a more fundamental fail of the pump mechanism.


Jonathan
 

·
Registered
Joined
·
37 Posts
Discussion Starter #9
Thanks Guys, really do appreciate the help here!!!! my gut feeling is that Jonathan is bang on the money, with problems on the Webers. Excuse my ignorance but I dont know what the accelerator pumps are? and yes I do think it was idle for a while before I bought it.

I imported the car from South Africa and it was interesting that I did notice the air cleaner was loosened off and it looks like they had started it the same way as me, by squirting petrol straight into the carbs.

thanks also for the starting techniques, I will use this and let you know how I get on at the weekend - regards,

Rich
 

·
Registered
Joined
·
80 Posts
The accelerator pumps deliver a shot of neat fuel into the inlet when you press the throttle. The four/six pump starting technique relies on those shots of fuel to enrich the mixture for start up, just as a choke would do.

When the car is warmed up that shot of fuel is needed to avoid the hesitance when you snap the throttle open.

There are various ways in which you can play with how much fuel gets delivered in the shot - but if the car is standard spec, and the carbs work OK the standard Alfa settings are all you need.

It may be worth taking the carbs off, cleaning, and fitting new gaskets and seals. Overhaul kits are cheap, and its a kitchen table job, which requires care and patience rather than great skill. Definitely buy a weber manual to help with that. I use a couple of litres of cellulose thinners to get everything clean. The pros use ultrasonic cleaning tanks.

Alternatively someone like Gower and Lee will overhaul for you for a modest sum.

Jonathan
 
1 - 11 of 11 Posts
Top