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Discussion Starter #1
I got a 1974 RHD 105 2000 GTV and can't get the thing started after a year since it last ran. It cranks forever at good speed but just refuses to start and idle after several weeks i admit defeat and could do some advice please.

So far I ended up replacing the entire ignition system and followed the manuals checking everything and i confirm i got a blue spark on all 4 cylinders. It does rarely catch and try to run but coughs a load of fuel and smoke out back out the carbs.

With static timing F with the rotor inline with the notch on distributor body and HT lead to cylinder 1 shouldn't it atleast fire idle?

Fresh fuel in the bowls made no difference either.

Bosch (mechanical advance) with points gap 0.3 mm and spark plugs are set to 0.6mm NGK B7ES

Mechanical fuel pump and regulator filter set to 3.0psi

Or is my problem fuel related?

It has pair of original Italian 40 DCOE 44 4L 13 and im struggling to find the correct specs for them my manual only goes upto 1750 then DHLA for 2000..

Mixture screw from just off closed to 10 full turns at 1/4 turn intervals, at this point anymore turns mixture screws falls out. I cycled through several sets of plugs started from black to black and very wet and dirty.

Finally i pulled webers apart checked everything and i got a mix of numbers, i gather the differences are for the vacuum take offs the manifold or should they be identical on each cylinder?

1 50f21
2 50f14
3 50f14
4 50f21

1 200 f34 138 (the emulsion tube looks very different to the rest)
2 200 f41 138
3 200 f41 138
4 200 f41 138

Float needle 2.00, Float level set to 8.5mm with gasket according to manual, this seems too high fuel drips out the front of the carb, whats the correct float needle and level?

What jets would be a step leaner or richer?

Thank you for any help
 

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Did you check the ignition timing?
Does it have compression? If it coughs I'd guess so.
Will it fire if you spray starting fluid in? The carbs seem in the ballpark enough to run.
Andrew
 

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The jetting is completely wrong. The emulsion tubes should be F16 and the idle jets should be 50F8, main jet 130.
Here are instructions for checking the fuel level: https://www.alfabb.com/threads/leaking-webers.680496/page-2#post-8449256
I don't know which type of idle mixture screw is used in 44's but if you do a search you will find pictures of the different types and guidance for adjustment in a post by Gordon Raymond. Early types are typically 1.5 turns open and later types about 4 turns but that assumes that the seating holes have not been damaged by over-tightening the screws.

The ignition timing does not have to be spot on to get the engine to run. I suggest that you get the engine to TDC on cylinder #1 and verify that the valves are closed. Then turn the engine back a few degrees. Rotate the distributor CW and then CCW until the points are just opening. Fit the rotor and verify that it is pointing to #1 plug wire. Then hopefully it will start and you can set the timing with a strobe light.
 

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Andrew's suggestions are very sensible - starter fluid and compression check. Was it running OK a year ago i.e. the last time it ran? What has happened since then? I have DCOE 40 44 / 45 carbs on my 2 litre. I don't believe that they were ever used as standard on the 2 litre, but were standard on the 1600 GT Junior. However, no reason why they can't be adapted to suit. i.e. Choke from 30 to 32, main jet from 117 to 130 or 135, idle jet from 50F14 to 50F8, emulsion F16. My fuel screws are about 5 turns out. Are you sure that the ignition timing is about right i.e. firing on the correct cylinder and no sign of back fire?
 

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Discussion Starter #5 (Edited)
I did a compression test a year ago and last week results are identical for cold 131psi across all 4 cylinders.
I timed it up many times now making sure i got TDC on cylinder 1 with all the marks lined up. I checked with a dial gauge, long 1/4 extension bar and thumb over spark plug hole and even borrowed a bore scope to make sure i was on cylinder 1 on compression stroke with both valves closed, everytime the marks lined up with no deviation.

Yes i tried spraying starter fluid whilst cranking with no real help apart from the odd cough.
I'm confident there's no vacuum leaks, all the throttle plates are lined up with the first progression hole out of the 3, with my 4 way syncrometer during cranking it seems they are all pulling a strong even vacuum across all 4 cylinders.

Mixture screw type

1604342




alfaparticle said:


Rotate the distributor CW and then CCW until the points are just opening. Fit the rotor and verify that it is pointing to #1 plug wire.
My manual says the opposite "At static timing mark F connect test light in parallel with condenser to earth and turn on ignition. I presume the test light should be on at this point? then says "turn anti-clockwise until test light goes out then turn clockwise until it lights just turn on. The rotor is pointing to HT lead 1 for cylinder 1.
(im aware my dizzy /oil pump was previously installed 180 degrees out at TDC rotor points towards bulkhead. it ran fine like this before)

I tried both ways with no difference at all to starting.

When it last ran, it started hot or cold everytime no problem very quickly no need for priming, no choke maybe slight touch on throttle when freezing cold weather outside. Since then its been laid up indoors on axle stands with half tank of fuel. Last year it drove wonderfully no hesitation no stalling no det or pinking and plugs were always a light brown when on long run or bit black if idling for long periods. From my records i set had the mixture screw 3.5turns and odd one was 4 3/4turns on cylinder 1 with the odd f34 emulsion tube. The car idled really stable down to 600rpm, the transition from idle to main circuit was superb no flat spots at any rpm with slow or rapid throttle opening in any gear or load. It really drove like modern engine on throttle bodies that had a very well mapped ecu.

This is why im unsure of which jets and parts to order its only thing i haven't replaced yet. Out of curiosity what carbs should the car have?

Would this reference be correct for me?

www.carbparts.eu/jetting_table

2000 GT Spider Weber 1962CC 4Cylinder 40 DCOE 76/77

Choke 32
Auxiliary venturi 4.5
Main jet 135
Idle Jet 55 F17
Emulsion tube F34
Air Corrector 210
Starter Jet 85 F9
Pump jet 35
Back bleed 60
Needle Valve 150
 

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The jets for DCOE76/77 do not apply to your carbs. I listed the correct jets in an earlier post.
 

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Discussion Starter #7
Thank you for clearing that up i was getting confused with the DCOE versions and equivalent jet and needle numbers
Is there a parts list for 40 DCOE 44/45, the ones i have list things like orings between screws and springs whereas my carbs doesn't appear to have them.
I like to double check nothings missing or incorrect parts have been fitted in the past.

Im going to order the following

Main jet 130
Idle Jet 50F8
Emulsion tube F16
Air Corrector 200
Starter Jet 85F9
Needle Valve ?
 

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Try changing the spark plugs, modern fuel tends to kill plugs if they are not heated up and 'burned' in after starting. A new set of plugs typically requires 20 to 25 miles to be considered "run in"

If one of mine won't start, I change the plugs and fill the float bowls with fresh fuel

Ciao
Greig
 

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So definitely getting spark and definitely ignition timed correctly? With all the start attempts are the plugs wet with fuel?
 

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What size venturis are in the Webers - probably either 30 or 32. That influences main jet size.
150 needle valve is non the small side but it should be OK. 175 is the next size up.
 

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Discussion Starter #11
Yes i changed spark plugs frequently so far i used 40 spark plugs (10 sets of NGK B7ES ) also fully recharged and swapped bosch battery every day. I had some other spark plugs for the Alfa sadly no difference either.

Yes plugs are wet at each attempt, im definately getting a good blue spark (given myself arc eye couple times). I also have a spark plug light on each one indicating they are firing in the correct sequence.

Venturi size is 32

With a large syringe i sucked out the old fuel from the bowls and filter/regulator then replaced with fresh fuel 99 RON each time too.

It has all the signs of life which is why im lost now.
 

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Yes i changed spark plugs frequently so far i used 40 spark plugs (10 sets of NGK B7ES ) also fully recharged and swapped bosch battery every day. I had some other spark plugs for the Alfa sadly no difference either.

Yes plugs are wet at each attempt, im definately getting a good blue spark (given myself arc eye couple times). I also have a spark plug light on each one indicating they are firing in the correct sequence.

Venturi size is 32

With a large syringe i sucked out the old fuel from the bowls and filter/regulator then replaced with fresh fuel 99 RON each time too.

It has all the signs of life which is why im lost now.
 

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Did you check the fuel level as described in the link from post #3 ?
 

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Discussion Starter #15
Did you check the fuel level as described in the link from post #3 ?
Yes im familar with that method I used both vernier caliper and needle depth gauge both measured the same.
I measured 29mm from machined surface of emulsion tube holder to fuel level and thats with floats set to 8.5mm
Now to reach 46mm i had to set the brass floats to 14.5mm

This solved fuel comming out the front upper hole, however a fresh battery load of cranking later plugs are dry and not a single attempt of a cough.

I reverted the float level back to 9mm and now plugs get wet and fuel level is just below upper hole at the front above the barrels. Now depth from surface to fuel 32.5mm

Main jet 130
Idle Jet 50F8, is it worth while getting 50F14 as well would that be considered leaner?
Emulsion tube F16
Air Corrector 200
Starter Jet ?
Needle Valve 175

Any sign of life if you pump the accelerator say 5 times before cranking That's the process mine needs.
Sadly no
 

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It seems curious that the car has gone from starting / running so well to a complete non-starter, which suggests a problem affecting all 4 cylinders. But you seem to covered all the things that could affect all 4 cylinders. Any chance that the air filter could be completely blocked? i.e. have you tried starting it without the air filter on? Removing the air filter would give an opportunity to look at the throttle plates and see if you are getting fuel from the pump jets.
 

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Discussion Starter #17
I started the thread without the airfilter and had the carbs on and off the car multiple times now checking everything step by step. I can confirm im getting fuel through i can see down carbs with my little mirror light plus the plugs are wet with fuel too.

The fuel float level is bugging me now am i too high or too low? All manuals and references i can find say float level should be 8.5mm as it was previously when it was running perfect. i remeasured again im getting totally different numbers from the link in 3rd post like 95mm total from bottom well to top of machined surface of emulsion tube holders.

I borrowed another compression tester and leak down tester im getting 165psi on all 4 cold.

The only other thing i have not tried is swapping out the standard distributor but finding one is proving difficult.
 

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Just an idea, check 'again' the position of the leads to the spark plugs, firing order 1342 !
When I was young, I once looked for two days why my car wouldn't start untill my father asked me about the correct sparking sequence for a 4 cylinder. In spite of having checked it myself more than once, I still made an error. 5 minutes later I was driving the car.
 

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so it has been running wel and will not start after a year
check the ground connection between engine and chassis.
when you start the startermotor will have a hefty current and this current, with a not so good ground connection, will result in an engine voltage level a couple of volts above ground. Not much, you will not notice a drop in cranking speed but this "raised voltage" prevents the coil from being properly magnitised to deliver a fair spark.

as all engine mounting points are rubber, the contactbreaker uses the same ground connection as the starter.
 
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