Air cooled 2ltr CU in Portugal - running like a pig.

Big lumps of metals and spanners. Including servicing and fluids.

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tobydog
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Re: Air cooled 2ltr CU in Portugal - running like a pig.

Post by tobydog »

How much voltage above 5V does the Hall sender need to give a reliable output?
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937carrera
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Re: Air cooled 2ltr CU in Portugal - running like a pig.

Post by 937carrera »

The voltage measurement being taken isn't from the hall sender, but the wiring to the hall sender, it isn't a functional test of the hall sender itself is it ?

Just took some quick comparative measurements from my CU, which is working fine

Battery voltage 12.66 v
Voltage at coil 12.70 v
Voltage across outside pins 9.71 v, though it does initially flash up as 13.28 v on the meter
Voltage from middle pin to earth 5.66 v

So it seems that it is normal not to get the full 12v to the hall sender, so the wiring to the hall sender in the OP's van seems OK.

I suspected fuel at first, and have moved onto suspecting ignition, there are numerous tales of erratic performing T25's who are cured by changing of hall sender or ignition module, but there's already been a swap of ignition module, so that would seem to rule that out.

It might be worthwhile if the OP could let the engine warm up and then run the engine at a fast idle (say 2000 rpm) for a few minutes and see if the misfire occurs then as there is a chance that it could be something electrical breaking down under heat. Another video so we can listen ?

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1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

porthyt
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Re: Air cooled 2ltr CU in Portugal - running like a pig.

Post by porthyt »

Thankyou all for your ideas and suggestions. Some of you have spent a great deal of time thinking and writing posts. I managed to find the holy grail of VW parts here in the Algarve (from a forum user on the Samba) and he was able to lend and eventually sell me a used rhs solex carburettor. Fitted it and the van has been razzing around all day - 60mph uphill, overtaking - lovely jubbly. The guy also checked vacuum equalisation across the carbs, timing and gave me parts that I struggle to find.

A fine example of the VW community spirit.

Cheers all
Josh

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937carrera
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Re: Air cooled 2ltr CU in Portugal - running like a pig.

Post by 937carrera »

:ok

So it was a fuel problem then, did he find anything in particular wrong, or was it simply a swap over & cured ?

Do you think it was finally related to the parking on the hill ?

Anyway, glad you're sorted and thanks for giving the update.
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

porthyt
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Re: Air cooled 2ltr CU in Portugal - running like a pig.

Post by porthyt »

Yeh no problem - always find it frustrating when people don’t write how they cured it. No idea why it blew that cap off the old one - all I can think, tying in with the hill, was that I worked it too hard. Honestly I was reversing up a 15% hill, in 30 degree heat, with about an inch each side of the van. I think maybe I cooked it a bit. Fingers crossed it is all rectified now. I have defo learned a lot more about my van.

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937carrera
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Re: Air cooled 2ltr CU in Portugal - running like a pig.

Post by 937carrera »

What you gonna do with the spare carb ?
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

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937carrera
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Re: Air cooled 2ltr CU in Portugal - running like a pig.

Post by 937carrera »

Me again Josh, trying to understand what went on. I think I better comprehend what you were saying now when referring to picture 7 in the Samba thread. I zoomed in on the picture this time and could see "Solex 100" marked.

A bit lower down there's a post by Frank Bassman which identifies this component as the emulsion tube, it's a pressed in jet. He then refers to https://www.thesamba.com/vw/forum/viewt ... bs&start=0.

If you look at the picture in the fourth post, is that the bit that's missing on yours, made of brass ?

If that's missing, the question is where has it gone. It's either already gone through the cylinders/valves without causing damage (lucky boy), or it's wedged somewhere waiting to go through. :(
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

porthyt
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Re: Air cooled 2ltr CU in Portugal - running like a pig.

Post by porthyt »

Yep that’s the bit. Have no idea how it came out. I’m hoping that’s it’s been and gone through my engine. Without removing a lot of hardware and looking for it I have no way of finding it as it’s brass so not magnetic.

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