Single Venturi auto carb leaking (+startup issues)

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thanasis
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Car(s): Ford Capri MKIII 1.6 GL Auto
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Re: Single Venturi auto carb leaking (+startup issues)

Post by thanasis » Sun Jul 14, 2019 5:00 pm

The brass float looked fine, do you suggest checking it again and replacing it? Is it worth it at this point? It had not visible cracks, holes or wear. The only other thing that comes in mind was that the needle i replaced was from an autolite kit and it had a pointy brass tip, but the one i took out had a soft red "rubber" tip. In size and shape they were identical. I don't think it makes any different because i have seen this new needle in many other original ford kits.

Also, does anyone with experience on this kind of carb knows in what position the mixture screw is more likely to be normally be in?
5 full turns or 5 half turns before being fully screwed in? What sounds more normal out of these, because i messed up while writing down my initial setting...

Mc Tool
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Re: Single Venturi auto carb leaking (+startup issues)

Post by Mc Tool » Sun Jul 14, 2019 10:01 pm

That needle is in exactly the right area for the problems you have. I would put the old rubber tipped needle back in for a try. I also get a cotton bud and cut one end off, stick the cut end in a battery drill, dip tother end in brasso or autosol and give the inside of the float valve seat ( the brass bit that screws into the carb body ) a good clean/polish, particularly where that rubber tip touches
you know it was a goodie when the end is stickin up out of the water

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thanasis
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Re: Single Venturi auto carb leaking (+startup issues)

Post by thanasis » Mon Jul 15, 2019 3:40 pm

I will reinstall the old valve and needle and see. I am just now finding that my kit had a little red gasket inside that fits the valve's thread... I believe it is meant to go there but the old one didn't have no gasket either and i didn't put it in... (edit: the workshop manual shows no washer on the valve housing btw... edit2: well, is says about a sealing washer in the text but it's not shown in the exploded view, damn it) If it is a flooding/float issue, it might as well be this.

For future reference i am posting this vid from Mike's carbs that shows this exact procedure on a very similar carb (autolite1100).



Let's hope that washer and valve cleaning was the case...

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thanasis
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Re: Single Venturi auto carb leaking (+startup issues)

Post by thanasis » Mon Jul 15, 2019 6:44 pm

There was a washer (i forgot that i put one in) but the valve housing was really loose. I put the old one in with the old valve and voilà! It returned back to the exact! old problems and behaviour... Hot restarts are almost impossible once again, the bogging down is less than before and of course it can't idle for more than 20secs without shutting down and refusing to restart. Flooding is certain. I hate this carb.

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Re: Single Venturi auto carb leaking (+startup issues)

Post by Not_Anumber » Mon Jul 22, 2019 2:10 pm

It must be said that you have incredible tenacity with this carb. I had one of these carbs on a 1.6 Capri in the early 1990s and after a week of trying different things I changed the manifold and carb for a 2nd hand 32/36 and enjoyed complete reliability & several extra bhp. If you take that route just get one with the linkages for a 2.0 auto. This would be exactly what was fitted to the 1.6 S automatic when it was made so is very much a known quantity.

Paul G
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Re: Single Venturi auto carb leaking (+startup issues)

Post by Paul G » Mon Jul 22, 2019 5:09 pm

thanasis wrote:
Mon Jul 15, 2019 6:44 pm
I hate this carb.

These problems have been going on for over a year now. Time you threw it away and got a new one.

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thanasis
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Re: Single Venturi auto carb leaking (+startup issues)

Post by thanasis » Wed Jul 24, 2019 4:01 pm

I will open it one last time today and check and readjust the float height. I'm also gonna dunk the float into a glass of water to be sure this time. If it's faulty i will try a new one. If nothing happens, i'm done. Not touching this carb ever again. I will go in the Weber route as soon as i can.

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thanasis
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Re: Single Venturi auto carb leaking (+startup issues)

Post by thanasis » Wed Jul 24, 2019 7:28 pm

I think i fixed it! Old valve seat, new brass tip valve, float was ok with no leaks but the height adjustment wasn't. Even though i had previously gone with the 28-35mm float height adjustment from the workshop manual, i had all these problems. So, at first i tried the 35-50mm (gt or 2.0 spec) which it did fix the running problems but at the first test drive it was getting fuel starvation relatively easily (undrivable over 70km/h). So i took it apart again and i decided to go with something like 32mm min, 38mm max and the fuel starvation is gone.

The startup is great, the bogging down is gone and most importantly it idles perfectly when i stop and wait. Hot restarts are instant. It purrs really well when i lift off and coast. I'll see how's the cold start tomorrow morning but i have a feeling it's going to fire up at once. Mixture screw is kind of messed up a little and propably needs replacing but i don't think it really matters for those problems. Right now it's at 5 full turns from the end (anyone knowing if that sounds reasonable?)

Thanks for all the words and advice. I will update with how it really drives tomorrow.

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Re: Single Venturi auto carb leaking (+startup issues)

Post by Not_Anumber » Thu Jul 25, 2019 12:05 pm

Thats a n excellent result. Well done for getting there.

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