been having trouble with my twin solex carbs. I cannot get the idle speed to remain constant, It seems to wander all over the place.
I put the van into John Forbes for him to take a look and Gary checked everything over, timing, points, plugs etc. He replaced the idle circuit fuel cut off solenoid as this was dodgy. He tried to set the idle speed but after a short drive the idle seems to reduce and consequently the van keeps stalling when it comes to a stand still (very annoying!). I have tried to reset the idle speed but it always seems to go back to low idle.
John Forbes said that I may have to have the carbs rebuilt. Is it worth rebuilding the carbs or should I replace them with something else like Webbers? Also how tricky is it to rebuild a set of carbs? I expect the hardest part is balancing them and setting them up afterwards.
Theres a guy called Laurie Ellis who can overhall carbs, but I dont have any contact details, alternative you can get new dellortos/webers from Euro Carb, ready jetted for the engine, costs a few pounds though. My brother can set them up. From your post if you’ve been to johns already the chances are the carbs ore worn, they tend to wear at the spindle, causing air to be sucked in which ruins the mixture, causing uneven running.
There was some bloke at the Scottish Volkswagen Owners Festival for a few years who was totally boned up on refurbishing and rebuilding stock VW Solex’s and anything else you could fling at him. Rebushing spindles was one of his skills.
Someone must remember his name.
mat, to send a message to my brother just click on User listing above and click on Bruce M and select send him a message. This is the best way to contact him!
The solex twins on T4s are often worn out and leaky. Check round the base of the carb for a wet look (its usually dirty and easy to see) especially if you pump the trottle a few times and the engine is cold. The spindle area wears out but can be refurbished (as per above). Make sure all the vacuum hoses and balance pipes are connected and the rubber hoses aren’t perished and letting in air. I’m sure Gary would have checked that tho as he knows what he’s doing.
If I remember correctly the set up of T4 solex carbs is a bit strange. I vaguely recall one carb supplies the fuel for idle and the other side is fed through the balance pipe , could be wrong tho.
If you opt to replace them , 34mm single barrel dells or webbers would be okay for a standard spec motor. Get them with the T4 manifolds of course and jetted to suit. When they are set up (pretty easy), they will give you better gas mileage cause they are not leaking.
My fuel economy problem was due to a knackered spark plug, the engine was only firing on 3 cylinders. I guess that would do it! Engine running fine whilst driving now.
I still have the problem of it stalling at idle. I adjusted the idle screw the other day (It was about 1.5 turns out) and the engine idled well and didn’t stall. After a long run to Dunbar and back the idle problem was back and the engine was stalling at junctions again. I checked the idle screw and it had screwed itself back in again. 1.5 turns out again and the engine is running fine.
I guess the idle screw must be worn or something, do you know if I can get a replacement? If not could I apply a small amount of thread-lock to the screw to keep it in position?
Took the idle screw out last night. There’s no spring but there is an o-ring fitted into a machined groove just above the thread. Looks a bit tired but I couldn’t find an o-ring (out of a assorted box of 200!!) that would fit. I ended up using a bit of PTFE tape on the thread. Seemed to hold the idle speed last night, however my wife phoned me this morning to tell me that she had problems driving the van to her work. Personally I think she just wants me to hurry up and get her car through it’s MOT so that she doesn’t have to drive the van.
check for air leaks on the rubber elbows and any of the other hoses and pipes that are in there. They can cause this type of problem. Replacements are fairly easy to get. The temporary repair I did with self-amalgamating tape has lasted about three years now (I do have the proper bits in the door pocket).
Problem sorted (I think). Managed to find an o-ring that fitted the idle screw, engine running better and keeping it’s idle constant.
One other thing…
How do you get POR15 off your hands, arms, face etc?? I’ve been wandering around for the last few days looking like I’ve got some kind of weird skin disease :huh:
