Cold start blues

Rincewind · Post by **Rincewind** » Wed Apr 18, 2007 8:07 am

Since i'm relatively new to acvw's i'm not sure if i even really have a problem.. But here goes anyway..

Last week i got my car back with a reconed 1600 tp engine, and a brand new solex 30/31 carb.. The problem is when driving off after starting the car, especially when the engine's cold.. Unless i slip the clutch for a long time when pulling off the engine basically splutters and the car won't accelerate.. Once i get going and the engine revs get above a certain point exactly the same thing happens again.. So it seems there is a very limited rev range where the engine will work.. As i drive the problem gradually gets less and less which makes me think its something to do with the automatic choke, but i may be way off.. Do i have a problem or is this just the norm for my engine when it's relatively cold? Sorry if this is a very naieve question but i gotta learn these things somehow!

Merlin · Post by **Merlin** » Wed Apr 18, 2007 8:28 am

's up?

This is not really my field of expertise, but no, it shouldn't be like that.

Also, it may or may not have something to do with it, but afaik, stock 1600 TPs run Solex 34(3)s.

N.

Post by **fig** » Wed Apr 18, 2007 8:29 am

The new Brosol 30/31 carbs are not necessarily correctly jetted for our altitude, and I have heard that some of them are set up for methanol.

Try using the main, idle and air correction jets from your old carb and see if that helps.

The only problem that's likely with the choke is sticking open, which will show up when the engine is warm not cold. In general, SA doesn't get cold enough to really need the choke and you can safely disconnect it.

Rincewind · Post by **Rincewind** » Wed Apr 18, 2007 9:12 am

I've done some research on the stock carb and it is a 34, but everything i've read says the 30/31 is the most common replacement as it has less of a tendency to create flat spots, and is only marginally different in performance.. But i did read that the jetting can be a problem.. Unfortunately i no longer have my old carb so there's no way of changing anything from that.. The engine and carb are under warrenty from the place that fitted the engine, so would they be able to adjust it to fix the problem? Other than this slight annoyance the engine is great, but im just worried that it could lead to problems with the engine later on if i don't fix it soon..

Rincewind · Post by **Rincewind** » Thu May 10, 2007 5:41 pm

So, after extensive research (read: 5 minutes with google) it seems this problem may all be due to my distributor.. I need to check what model distributor it is, but if its the 009 all my problems can be explained. It seems this distributor's advance is only governed by engine RPM i.e. centrifugal force (as opposed to the SVDA unit which uses vacuum advance). The most common symptom of using this distributor with a 30/31 PICT carb (which i just had fitted) or a 34-3 is a flat spot (sometimes small sometimes huge) between 550 and 950 RPM. Will check what distributor i have tomorrow and keep you informed. Hopefully if that is the problem i can find a SVDA unit for a reasonable price and have my engine running smooth!

Post by **calooker** » Tue May 15, 2007 9:24 am

The Solex/Brosol 30/31 PICT carb is jetted very lean not good for your new motor, get the main get replaced with a min. 127.5 main jet as the one in there is tiny, like 122.5. The 127.5 jet is used in most stock carbs the later 34 Solexes had a 130 main jet get that one if you can find one.

Merlin · Post by **Merlin** » Tue May 15, 2007 9:27 am

Rui,

Speaking of jetting, do I need to do anything to my Kadrons for the new setup?

Thanks, N.

Post by **calooker** » Tue May 15, 2007 9:31 am

We will need to check what main jets you have, but from previously working on those type of carbs they should have a 130 main jets which is fine up to 1800cc if not we will replace them no problem.

Rincewind · Post by **Rincewind** » Tue May 15, 2007 9:38 am

Thanx for the advice.. Now any idea where i could pick up a new jet? What will it set me back? And is changing it a job i can do myself or should i get some1 to do it for me? Thanx again!

Merlin · Post by **Merlin** » Tue May 15, 2007 9:57 am

Shot.

Post by **calooker** » Tue May 15, 2007 10:16 am

The dudes that did your motor will probably have a pile of scrap stock carbs that have a 130 jet ask them for one or tel carb city in JHB 011 334 4433. Easy to change, can be done with carb in place but will be a lot easier if the carb is out, the main jet sits in the fuel bowl and to get to it you don't even need to take the top of the carb off, the is a 13mm bolt that needs removing sits on the side of the bowl, then you can see the main jet inside the bowl which is removed with a flat screw driver, easy change.

Rincewind · Post by **Rincewind** » Sat May 19, 2007 7:05 pm

Thanx cal, i changed the main jet to a 130 and the difference is unbelievable! Flat spot is gone, engine has more power, engine idle's well, wow! I'm a very happy man right now! This is why i love this forum, where else could i learn so much so easily? Lets hope this engine keeps on running as good as it is now!