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But Mad North-Northwest
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Discussion Starter #1
Currently working out the bugs on the Giulia Spider (it has a 1750 with dual Webers) and one of the main issues is that I can't get the darned thing to start reliably when cold. I've tried pumping the gas a bunch before hand and using the enrichment circuit and nothing works. It'll *almost* start on the enrichment circuit but never quite catches.

If I use starter fluid it'll go and then I can keep it running with a little throttle for a minute or to until it's warm enough to idle on its own. Once it's warmed up it idles fine and hot/warm starting is no problem, it's just when it's been sitting for a while that it doesn't want to catch.

I'm still new on this whole Weber carb thing. Anyone have any suggestions as to where to start here?
 

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What fuel pump and pressure regulator are you using? If a mechanical pump, you can pump the pedal until you tire if there is no fuel in the Webers. An electric pump should be on for a moment or two to fill the float bowls before you try anything. Pressure regulator set for 3 lbs. Usually 65 or 70 starter jets are all thats required, IF the enriching device is operating correctly.
 

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But Mad North-Northwest
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Discussion Starter #3
It's an electric pump, and yes I've got it running when I'm pumping.

It looks like it's got an inline pressure regulator, currently set to 2 PSI. Should I increase that to 3? 2 seemed a little low to me, but since it runs awesome when warm I was worried about messing something up by changing it.

The advice I've been given on Webers is that "If they're running even close to okay, don't fark with them" :D I haven't built up the confidence to violate that credo yet.
 

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starting

What is the general condition of the carbs? If they've sat for a while with gas in them, you may have some cleaning to do. The "circuit" used for starting may have some passages slightly clogged. Does it idle ok once it starts, then accelerate, etc? If you can find a weber diagram somewhere that shows all the different "circuits" that will cue you into where to focus your cleaning efforts.

As Gordon hints, your enrichment device may not be functioning properly as well.

GMack
Minneapolis
 

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You are correct. Mechanically sound Webers do not lose "tune". Old worn tired plugged up ones are trouble. I restore most Alfa Webers for BB customers, but before you do anything to them, Increase fuel pressure to 3 lbs. Check to be sure both enriching device arms swing fully open and closed with whatever mechanism you use.
The starting circuit consists of two starter jets per Weber than can get gummed up.
More often, in the accelerator pump circuit, there is a ball check and weight valve, (one per pump jet) that can get funny, and below that in the bottom of the DCOE series are passages I refer to as the catacombs, that are the lowest point feeding this system. Dead dinosaurs form a glop that collects in there. Below is a diagram I like to use. Simplified, this shows another trouble area. Does the accelerator pump circuit seem to work once it's running?
 

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I just found this and photographed the cold starting circuit of the DCOE series.
 

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But Mad North-Northwest
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Discussion Starter #7
Cool, thanks guys. PO didn't drive it much so, yeah, it's probably been sitting for a while. From what you're saying sounds like they might need some cleaning.

Enrichment arms are definitely fully opening, and I'm reasonably certain the accelerator jets work. I'll try the higher fuel pressure and report back. Probably won't have time to play with it 'til next weekend, so keep the ideas flying if there are any other things to check.
 

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Weak spark and bad ign. timming can also make starting a bugger. You may want to see if there is a nice blue spark with a plug leade 1/4" away from ground and check the static timing.
On 'pumping the carbs', you are not in the Arctic, so 1 or 2 pumps is plenty before you start to crank. Hold the pedal down a little as you crank......
 

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But Mad North-Northwest
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Discussion Starter #9
Weak spark and bad ign. timming can also make starting a bugger. You may want to see if there is a nice blue spark with a plug leade 1/4" away from ground and check the static timing.
On 'pumping the carbs', you are not in the Arctic, so 1 or 2 pumps is plenty before you start to crank. Hold the pedal down a little as you crank......
Good suggestions. It's got an RSR distributor with an Ignitor solid state ignition module and a MSD Blaster coil so the hardware setup is good, but I still need to verify I'm getting good spark and that the timing is correct.

Incidentally, anyone know anything about this particular distributor? It says "RSR Santa Rosa" on it but darned if I can find any info on it.
 

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But Mad North-Northwest
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Discussion Starter #10
Finally got a chance to work on it. Kicked the fuel pressure up to 3 PSI and it started much better. I won't say it started *easy*, but I at least got it to catch on the third attempt which from what I hear is pretty typical for Webers.

Thanks for the tips, guys! I'll throw some BG44K in the tank and drive the crap out of it for a while and see how she does.
 

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But Mad North-Northwest
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Discussion Starter #11
Just as an additional followup, I ran a bottle of Techron through it and it seems to have helped.

The other trick is the cold start enrichment. Pulling the knob all the way out just floods it. If I pull it out a quarter, though, pump the throttle twice and crank it it'll fire right off. Then I just hold the throttle for about fifteen seconds, push the knob in, and it'll idle fine on its own.

It'll fire up pretty much on the first go now. Thanks again for the advice.
 

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Ignition at fault?

Just as an additional followup, I ran a bottle of Techron through it and it seems to have helped.

The other trick is the cold start enrichment. Pulling the knob all the way out just floods it. If I pull it out a quarter, though, pump the throttle twice and crank it it'll fire right off. Then I just hold the throttle for about fifteen seconds, push the knob in, and it'll idle fine on its own.

It'll fire up pretty much on the first go now. Thanks again for the advice.
Hello Gubi,

After I had my 1300cc engine rebuilt in 2008, my GT 1300 Junior Zagato was reluctant to start. The carbs had been cleaned and rebuilt, the fuelpump (mechanical) and had been replaced by a new one, the fuelsystem had been flushed, cleaned and checked.
Before the rebuild, using the cold start device had never been necessary. Two dabs on the throttlepedal and the car would start, just as 101/105Guy suggested. But now the car would only start reluctantly with half throttle after a few tries.
It turned out to be the ignition as 101/105Guy suggested earlier in this thread. In the end, we made new markings for TDC (Top Dead Centre) on the flywheel after which all the problems disappeared instantly. I do not suggest to do that, but your ignition could be the cause of your problems. Checking the ignition timing and checking the markings against TDC could be one of the things to.

Ciao, Olaf
 
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