The battle only makes it more satisfying! I picked up a set of reco'd duel solexs for $100ish... worked a dream, bargains are out their. You should be able to pick up a dizzy pritty cheap aswell.
did you check your throttle crossbar adjuster??
To be fair i only paid $5 for the dissy (plus one free), so i could just pick up another and put that in... its the carbs that scare me.
Struggling for motivation sorting the damn thing out though - my heart sinks every time i lift the engine lid
There should be a stickied thread for 1800 dualcarb faultfinding. I always feel angry when I think of them.
I'm leaning toward an unspecified carby fault. It's amazing. They can be completely ratted and keep chugging just fine, or have the tiniest thing out and make the motor run like a lawnmower.
Still trying to faultfind mine too. The carbs usually seem to be the issue though. If not, have you tried swearing at it _really_ loudly? Even if it doesn't help the engine, it'll make you feel a whole lot better.
If at first you don't succeed. Build, build again.
Vehicle: 1975 Special order delivery walkthrough panel based LCA pop-top camper. Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.
If i havent died first!
Every time I think "Hey, I know! It's (x) that could be causing it to run badly", I build up the determination to have a look. Sadly enough, every idea of a problem I had was true. I'd fix it, and cross my fingers. Start it up. Still runs wrong (Too damn hard to explain easily).
Others may know, Is there an easy way to dynamically check vacuum? I thought of the whole loop of plastic hose with water etc. But it seemed a little clumsy.
A thought. Are you absolutely sure the top gaskets of the carbies are perfectly seated? They can easily stuff up the running of the motor.
If at first you don't succeed. Build, build again.
Vehicle: 1975 Special order delivery walkthrough panel based LCA pop-top camper. Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.
hey General_Failure, good 2 c ya bak man.
Samblers, i get shitted very frequently at my bus, dont think your the only one lol.
Just keep trying to cross one thing off the list at a time.
Okay.. this may be off topic, being as you said the carbies had been looked at... but here goes..
I have a Nissan Patrol (1984)... don't laugh. About a week ago it started doing *exactly* what you describe. It'd go to 1500-2500 rpm, then just cut out.
Fortunately, the Patrol has a second choke that is pretty much like a second accelerator pedal. I had a party trick I'd do at times, where I'd drive from the running board, by leaning in thru the window. Pulling that choke out halfway solved the problem.
Anyway, after checking the timing, doing almost everything you've described, someone suggested it was crap in the main jets... can I say crap on this board? So I took em out, blew through them, and hey presto! No more kangarooing or driving with the choke half out..
Hope this helps.. I'm a new member.. trying to build up some karma 😉
Let good karma be upon you child!
Thanks for the reply... crap in the jets (see, i said it too!) would explain the problem... but i've blown them through twice, along with every other carb bit, so ive kind of discounted it.
I'm thinking its just one of those inexplicable things that will just magically go away after spending $X00 on some more carbs, a fuel pump and a distributor... but being an engineer (dont laugh) i HATE just replacing parts until the problem goes away. I like to see the proof!
Grrrrr!
Is there anyone in Perth who's got lots of gauges and stuff who wants to come round and have a tinker for a crate of beer ? 😉
mate where the hell were you when i was selling my last 1800 out of my 76' bay,
that was a perfect engine with comp tests and full rebuild receipts
came with all carbs n dizzy n everything cos iz doin engine conversion...
ended up sellin it all to VW shop for $350
ah well........
76 baywindow kombi - V8 & Weddle racing diff and gearbox
Daily driven beach cruiser
Okay... back to the drawing board 🙂
I've read through Muir's "Compleat Idiot", and Haynes '72-'79 Manual for 1700/1800/2000.
The only suggestions they have for your symptoms are that either the accelerator pump is not working properly, which you've eliminated, or the idle adjustment is incorrect, but hey, books - what do they know??
Muir says that for a 1975 Type II, the ignition should be at 5 degrees ATDC. Haynes say that 7.5, 10, or 5 degrees BTDC is correct, depending on if the engine is from Europe, US (auto) or US (manual).
Hope these help.
If it were me, I'd give each of the ignition settings a try, then have gander at the carbs. How's it running, with regard to idle speed, and temperature?
I know from experience how much fun (not) it can be squeezing around the 1800, but chin up! 🙂
[ Edited on 6-8-2006 by mpbriggs ]
Its not really acceleration thats the problem, its just maintaining any kind of cruising speed without flooring it.
As far as ignition settings go, i've got a single vac dissy with mech advance which i've looked up as requiring 7.5deg BTDC... I've currently timed it to about 10deg at idle because i think the mech advance isn't too hot and it runs a little better (smoother)... the other settings mentioned will be for alternative dissys i guess.
I'm still expecting about 10-20% more power than i'm currently getting though. Grrrrr
As for the dude who sold his entire engine for $350... thats just fackin nuts!
If anyone wants to sell me another set of twin carbs for this puppy then U2U me 😉
Sam
I have done this trick a couple of times to help clean out any dirt in the carby jets, and it works sometimes.
With the engine running and the aircleaners removed rev the engine to about 2000-3000 rpm
Cover the mouth of one Carby entirely with the palm of your hand.
The engines revs will die off but then give it 100% open throttle to try to keep it running.
The engine revs may still die down but ensure that you remove your hand before the engine stalls as it is then flooded and hard to start.
Repeat with the other Carby.
You only need to keep it covered for a few seconds (3-5seconds)
The reason this can work is as you block off the air supply the engines vaccuum draws large amounts of fuel through the jets and can dislodge any dirt particles
The other benifit is that with the palm of your hand feel the different vaccuums through each carby and also how well the other carby runs the motor while one is blocked off. Each side should have the same changes.
It is a bit of a bush mechanics procedure but it may show so differences between each carby or vaccuum and may even solve your problem.
Jeremy
Dude, I feel for you. I had a very irritatingly misbehaving dual carb stock 1800 too. Similarly, when she was playing up, I could very very very gently increase pressure on the acclerator and she would slowly but smoothly speed up. Then I'd hit a bump, or press a little too quickly, or a butterfly flapped its wings in Chile, and all of a sudden the bus would stutter, shudder, slow down and I'd have to PUMP the pedal to get anywhere. Picture driving across South Aus near the Flinders Ranges, 35degrees outside, heater stuck ON (it'd burn yer hand if you held your hand above it, until I disconnected it one day), and doing 40km/h. Not that much fun. And I could never figure this thing out!
The problem was intermittent. Some days she'd be fine, cruising at 85km/h for hours on end. Other days she just wouldn't want to go. And once the problem started, it'd almost never go away until the next day.
I noticed that it often happened for the first time on any particular day after we'd stopped for a break. So, the engine was hot from driving happily along, then we'd say, get fuel or stop for photos. Then after starting again, she'd be fine for a minute or two, a few km, and then wham, stutter, oh dear me! Back to shuddering along. I noticed that in this cripple mode the engine was shaking like mad. I therefore did a quick check: pulling the leads of cylinder 3 or cylinder 4 or from BOTH 3 and 4 resulted in absolutely no change in engine speed (OK, going by ear). Pulling off either of cylinder 1 or 2's leads resulted in instant death. This might be something you could try too, it's pretty quick and easy hey. And the tingling feels nice... Oh uh lets move on.
Of course, every morning when I booked her in to see a doctor, she'd be fine again. After paying $70 to be told there was nothing wrong (because at that time she was behaving of course) I realised I'd have to sort this out myself.
So one day she buggered up while driving along, and I happened to have my tools along with me (heh, in an old VW, never! :P) Anyway, I had by this stage decided that It was fuel related. So I opened each carby and lo and behold, the one feeding cyl's 3 & 4 was bone dry. I filled it up, put the lids back on, and drove home with not another issue. Now clearly I didn't actually DO anything there. The carby-full of fuel wouldn't have lasted all the way home, so I still didn't actually know the root cause. There are several reasons why a carby might not have fuel in it.
1) fuel pump buggered. Nah, other carby has plenty of fuel.
2) fuel line blocked downstream of T-joint. Nah, replaced earlier by me.
3) sticky needle valve. maybe!
4) freaking moronic dumbass finicky idle cutoff solenoid broken. maybe.
5) simple little piece of wire to cut-off solenoid having a loose contact.
Well, I replaced the cut-off solenoid with one I have lying around which has it's top cut off. Apparently that's pretty common. I also replaced the wire. Now I didn't replace the needle float valve thing just 'cause I haven't got a socket that'll fit in there to unscrew it.
I am not actually convinced that the solenoid cut-off valve was THE problem. But in the last year and a half she has not ONCE let me down. Absolutely no problems at all. I love that bus!
So it may very well be something small and simple. Try pulling the leads off, try checking the fuel level in the carbs, don't yet reach for the matches.
Hope that helps dude, cheers, Aurel.
Aurel,
cheers for that dude... tech help is so much easier to read when there's a story behind it! We too found the flinders ranges as hot as hell... and beautiful 🙂
I tried the whole gig a couple of times taking the lids of both carbies and seeing if fuel was present. There was (is)... but the float level is like 17/18mm from the top of the carb body on both sides, when its supposed to be 13mm. The books say you're supposed to be able to adjust this float level height by adding/ removing washers from underneath the needle valve.
Since I only had one washer underneath my needle valves i decided that i couldn't get the float level any higher and anyway i couldnt work out how it make a difference to the running of the van... the thing has fuel, right?
When I was putting the engine back together after our Bribie island disaster (so far from home!) we snipped the ends off the fuel cut-off solenoids and put in fixed jets where the 12V ones are supposed to be. Make sense?
Anyway, its driving a bit smoother now i've advanced the timing but its still lacking the power that i know it should have, grrrrr
S
What colour are your spark plugs? I don't suppose you've got a CO meter have you? I was just thinking that perhaps the plug colour would tell you whether it was running rich or whatever on one or both sides, but you said that you had the carbies tuned... Hmmm, interesting...
the low level of fuel in the float bowl could? be your problem.
i've just measure a spare float bowl i have and the 17/18mm fuel level comes very close to the inlet of the accelerator pump circuit in fact it only just covers it.
so basically you are driving down the road on the idle circuit or the main jet circuit either one is consuming fuel and it is possible that the accelerator pump intake is above the level of fuel left in the carby hence no transition just a big flat spot ?maybe?
I guess a way of increasing the fuel level would be to carefully bend down the tab on the float which closes the needle valve.
the fuel level of 12 to 14mm must be set correctly for the carbies to work properly.
you may be a genius
i shall look into this and post some beer if it turns out true 😉
