Club 80-90 Forums

yes strong smell of fuel and smokey is a good indication of over fueling.

don't bother with the ultrasonic, just buy a rebuild kit from brickwerks, sounds like the mechanic didn't do that. Brickwerks do two so go and measure your accelerator pump first (13 or 19mm)

if you have a poor seal on the float needle valve you will have fuel flooding into the carb, same is true if you have a bad main gasket. Many people open them up and don't replace the gasket(s) becuase you can't just buy one at the local motor factors and the rebuild kit is best part of £50

Good advice...

8ball wrote:The guy I bought the van from replaced the accelerator pump whilst recommissioning the van, and brake servo hose has been renewed. In addition I have replaced the six small vacuum hoses. The mechanic I've taken it to who has tried to clean and set it up says that he eliminated a vacuum leak as the cause of the problem.

Here is a (very bad) picture of the choke flap:



and a video of the engine idling...
.

why has the pipe to the pull down been removed?
does the pull down open the choke under acceleration?
does the choke flap open fully?

kevtherev wrote: why has the pipe to the pull down been removed?

I was just making a record of what went to where. To correct an earlier post, I mis-remembered what Edwyn had told me on the phone, the later carb on an earlier engine wouldn't be detrimental to performance, in theory it would in fact be a slight improvement Anyway, after a good chat with him and weighing up the satisfaction of doing it myself against the increased chances of getting the van running properly before the easter break, I've decided to send him the carb for repair, will let you know how I get on.

So the latest is, had an email from Edwyn at Bromyard, reporting the following faults, since rectified:

Visual inspection
2nd stage control segment seized allowing -
2nd stage throttle allowed to float
PD unit vacuum spigot blocked
choke unit postion incorrect
a' and 'b' settings 2nd stage incorrect
idle set at high not allowing actuator to operate down to hot idle


External test
PD unit ok
CO set very weak
Existing actuator = 9.8mm

Engine test
without corrective action --- Starts but bad faltering at high revs


Internal inspection
inlet filter omitted - no wonder I couldn't remove this to clean it in my initial investigations, it wasn't there to start with!
air jet blocked
acc pump vent blocked
damaged seal on acc pump jet holder
2nd stage throttle plate base adjustment incorrect

Great service so far, he has kept me fully updated at all times, including sending this update on a Sunday. As the last place I took the van to say they eliminated an air leak as the cause of the idling/lack of power problem, fingers crossed this should see a big improvement. Will hopefully be getting the carb back in the next couple of days, he said he would do further testing, setting-up and re-checks for correct cold start and kick-down phase today. Will report back once I've refitted it.

Impressive list of faults!

kevtherev wrote:Impressive list of faults!

Yep, that's what I thought too. Some things best left to the professionals. It's not a cheap service but you get what you pay for. The carb is reset to factory tolerances, and if this allows me to get the van back on the road and ready to go for easter, and to not have to resort to junking the Pierburg for a Weber, worth every penny.

not to fit a weber (spit) is worth even more!

excellent service from Bromyard as usual

Impressive indeed Kev... should run as smooth as a silken thing when fixed.

Shall we put Mr Bromyard VW in the Wiki, assuming not there already?

Hello again, it's been a few weeks but just thought I'd bring you up to date with the Pierburg saga. The carb came back from Bromyard in great condition and I refitted it and all was well... for a few minutes. The same problems reappeared with uneven, hunting idle and drinking fuel like it was going out of fashion. This is when I started dabbling with the timing settings as detailed in another thread which obviously made no improvement. I'd enquired with a few places in Bristol but none could look at the van reasonably soon, so as I was visiting my other half's parents in Shropshire, I thought I'd see if there was any chance Roger at Bromyard might be able to as he was 30 mins down the road from them. Thankfully he agreed to inspect the van and an appointment was made for Saturday at noon. After an hour and a bit spent with him checking everything over, during which time he patiently imparted a lot of very useful knowledge, the conclusion was that the carb was blocked somewhere and would need to be cleaned again. I needed the van to return home the next day, so thought I'd take a punt and ask if there was any chance I might be able to leave it with him, which to my surprise and gratitude he agreed to carry on working on it the following morning.

The next morning he rang to say he'd had the carb off, cleaned it and tried it on his test engine and everything was working as would be expected of it, but when he put it back in the van the same old problems reoccured. The breakthrough came when he removed the fuel pump and drained it, and a load of debris, rust and god knows what came out, which was obviously getting sucked straight back into the carb and messing things up again. Fuel pump flushed with clean fuel and blown through with the air line and everything reassembled, timing set and idle and CO adjusted, and a secondary in line filter installed (I am aware that opinions differ on whether this is a bad thing to do, but have experienced no problems so far, long term fix will be to flush out/replace the fuel tank and lines), the van was running a million times better, but still had a slight misfire on no. 3. The next day I replaced the plugs with the correct Bosch W7DTC items from the Green spark plug Co. which had arrived over the weekend, and everything now seems sweet as a nut. Starts on the button with correct warming up procedure, purrs quietly at tickover, cruises happily at 70 and getting 25ish mpg which is a vast improvement.

Just also to say, Roger was an absolute gent, really knows his stuff, and is a thorough professional. If you need any work doing to your Pierburg I'd have absolutely no hesitation in recommending him and would say an addition to the wiki would be well deserved.

Thanks to all for the advice and comments, I hope one day I might be able to give back to the community with everything that I've learned in the past couple of months, keep up the good work.

Glad you got it sorted and thanks for reporting back on the cause(s)

I am a bit puzzled by one thing though, the Pieburg is supposed to have a fine metal gauze filter built into it's inlet pipe and that should have stopped crud getting into the carb. If it was missing (as one may presume it was due to what you report) then the nice man at Bromyard would / should have spotted that (during the servicing) and replaced it ?

One also would question why a second filter was needed, as the fuel lines are rubber and plastic the rust can only come from the tank, which "should" have a filter just after the outlet, and would have caught any crap long before the pump.....

ghost123uk wrote:Glad you got it sorted and thanks for reporting back on the cause(s)

I am a bit puzzled by one thing though, the Pieburg is supposed to have a fine metal gauze filter built into it's inlet pipe and that should have stopped crud getting into the carb. If it was missing (as one may presume it was due to what you report) then the nice man at Bromyard would / should have spotted that (during the servicing) and replaced it ?

One important thing I forgot to mention - the filter was indeed missing when I sent it to Bromyard and it came back to me with a new filter installed. I then managed to put a hole in that filter. As it had been missing previously, I wanted to see how it fitted, but like a tit, managed to damage it whilst removing it. This was before the installation of the carb, so I would have been allowing contamination back into the carb as soon as fuel was pumped through again.

Mocki wrote:One also would question why a second filter was needed, as the fuel lines are rubber and plastic the rust can only come from the tank, which "should" have a filter just after the outlet, and would have caught any crap long before the pump.....

Well, this is confusing me too. When I first bought the van it seemed to be running okay to start with, and a brand new filter was in place. After a couple of weeks that filter was absolutely full of muck, very murky fuel and full of deposits. I changed it for a generic one from the local motor spares shop which was a bit bigger than the one that was there originally, and that's when the problems really started. Immediately from fitting it and firing it up it ran like absolute sh*te and refused to idle at all. I've no idea why it would make such a difference, but I can only assume that some crap from the tank made it through to the pump at this point. I think I've still got the filter somewhere so I'll try to dig it out and see if there are any obvious defects that would have let anything through. Anyhow, I've done the best part of 600 miles since the work Bromyard did and had no problems at all, so I'll carry on as is and continue to monitor the situation.

kevtherev wrote:There are many ways for unwanted air to leak into the pierburg. Air that will stall an engine after the choke comes off
Unless they are eradicated cleaning is futile.

second veturi butterfly
choke pull down
distributor advance

all these attached devices use a diaphragm to operate, if the diaphragm is split then air will leak in.

the brake servo hose (braided type) is another known culprit for air

Thread resurrection time again!

Sounds like the problem I have. The engine has been cutting out when trying to pull away from traffic lights for several months. Then today just started cutting out on idle all the time. Really hard to drive. The engine starts with the choke. As soon as the choke comes off it stalls on idle. Pipes all look ok, but not tested. Before going to the time and cost of rebuilding the carb, maybe finding any leaks is the best option.

Is the brake servo hose also linked to the carb?

It's linked to the inlet tract. Same thing if it's leaking