Another idling problem (1600TP 34PICT3)

Over the last couple of days I've been having a(nother) go at getting my van to idle (1600 TP), I've put a different solex 34PICT on that I rebuit as a spare, but it's still difficult to get a stable idle & I've put my new coil on & no change.
On yesterdays attempt after I though the van had warmed up I was having to hold the throttle open quite a lot to keep the engine running, but it's smooth at this higher speed. I set the volume control screw back to about 2.5 turns out & the van started, idled & I carried on to tweak the idle somewhere about 900rpm. Has the engine warmed through a little whilst I was having a go at the carb, does this indicate carb icing? I went for a few miles drive around & it idled just fine.
Today it's not idling, I've adjusted the choke on a little longer and after a lot of faff it just started to idle although it's hanging by a thread, chuff chuff chuffing & almost stalling.

I've done several sprays with carb cleaner around the manifold, joints & plugs & no change.

What else can I try? I have another distributor which I need to clean-up, is this worth a swap?

LC

 

You've tried all I would try before I would start swapping other parts. If you have a dizzy you may aswell give it a go.

 

may be i'm just bad a carb rebuilding & setting...

I do need to have a feel of the pre-heat pipe to see if that does carry heat, but apart from that i'm running out of ideas.

Is it reasonable to expect to start the engine up from cold, let it sit there on choke with a bit of revving & when it comes off choke it idles without having driven off to get the engine really working?

 

Hi im no tuning expert but i have same set up ??? like you have fiddled till the cows come home in winter, summer is sweet , so now i just set revs up a tad in winter :. Assume cable is connected ok and pedal return spring ok?? Good luck

 

yeah, new acc. cable last year & greased all pedal bits so they all snap back with the springs

 

The usual stuff: did you give all the passages a good clean out in the carb, any air leaks on manifold or spindle, choke truly coming off properly, etc?

Are the tappets ok - these can have an effect as well.

FYI, I've cleaned/used two old Solex carbs (I've avoided new) and have never had any trouble with either of them. Driving off from cold is preferred - vans starts and runs straight away, but you shouldn't have any real probs when the choke comes off at a standstill. The engine may stumble (or even die), as the engine's not truly warm, but should start up & idle ok.

 

I had a similar problem a while ago and on checking my in-line fuel filter it was clogged and seemed to be starving the carb when idiling. I changed it and it was fine. Can't say if it's the same problem, but maybe worth checking. Also maybe worth checking the thermostat flap on the air filter.

 

As Snotty said all you can do is clean the carb again, i had a similar problem i rebuilt the carb washed everything out took out the jets and cleaned them. i was about to junk the carb. then i had one more go and used and air line to blow all the channels through with petrol. and its been fine since.

 

I don't know how many miles your bus has done but carbs do wear out. It's typical I'd say of lower capacity engines. Citroen 2CV's and Dyane's suffered from carb problems due to worn spindles and shafts. It totally messes the air/fuel mix and no amount of turning it this way or that will cure it. In some cases it seems premature but the carb is forever going over the carbs full range because you have to drive it that much harder than you would say a 2 litre bus or a Beetle.

If there is wear and tear there will be problems.

 

I took the van for a run today, a start from cold (frosty) & drive straight out, no faff.
After several steady laps of the block I pulled over & the choke was off & the van idling way too fast (which is better than stalling for the moment) this is after leaving it yesterday afternoon barely chugging over.
I've left it running fast for the moment. It's had a nice run out & warm through but it's so long since I've driven it I had paranoia it was sluggish but I just think I've got into modern car mode again, I've finally put the tax disc in the window which had run out at the end of september so it's at least this long since properly having a run.

On the open road I took it up to 55-60 a few times & up some long hills (not that it's very hilly in Lincs!) so I'm fairly happy the fundamentals are all okay, just some niggles for another day.
I'll see how long it runs smooth for this time, it'd be nice to beat 100 miles!

 

When it's warmed up, is the stepped fast-idle cam back in the "normal" position? Sometimes the choke shaft gets sticky and the cam doesn't drop down into the right position. A tap on the end of the shaft with a hammer normally does the trick.

No reason why a van shouldn't fire up, drive straight off and come off the choke by itself. It all works pretty well if everything's in good nick.

 

I had no end of running problem's and this was very helpfull and got me up and running in no time and tell's you everything you need to know to sort out any running problem's hope it help's you too, I have actually printed them off and laminated them and keep them in the van as you never know when you might need them! ;D

http://www.vw-resource.com/34pict3.html

 

Have you got all the heating/cooling bits in place? I had really bad problems with this years ago and found it was because someone had removed the flaps in the fan housing and the thermostat etc, so the engine was in permanent summer/hot mode. consequently it was running way to cold in winter and the inlet manifold was icing up. It ran like a dog, never idled properly once the choke went off, would seem to be ok for a while then would stall at junctions randomly etc.

 

dont drive ya bus when the idle is too fast ........many 1600 aircool are a bugger to set up.....i suggest you do valves,points set up properly ....gap plugs ...time engine and then look at carb ........if the carb is bang crap ...it would either over fuel or under fuel .....or stutter like bugger .....gis a pm if you want with whats wrong and ill help you out ....also tell me what you have done ....maybe its just a simple tune up needed........carbs do wear out ,but not to the point when they make ya engine tick over fast unless even with over-fueling problems....but you would notice more smoke from exhaust if the carb is running with choke out loads..
regards johnny the moaner

 

flaps & stat are all good as I went through these when the engine was out.
I've had a run out today & it was stalling at junctions again, this is after it was fast idling a day or two ago & i've touched nothing since. After leaving it for a bit & coming back it seems to idle better & i've now adjusted the speed back down a bit.

I checked through the pre-heat manifold pipe this time, the near side over cylinders 3/4 was hot, as in it vapourises a bit of spit & you couldn't touch it, the off side over cylinders 1/2 was hot, but you could keep hold of it without burning yourself.

How should this pipe work? a clear flow of exhaust through that heats the lot up? I seem to remember large & small oriface gaskets on beetles, have I a blocked pipe & could this be my problem. I don't remember checking if this was clear when I put my engine back together.