I'll try and keep this brief.... 🙄
My '75 1800 kombi is running poorly - I have previously described this as a 'hesitation' problem but can more correctly be termed 'stuttering'. In the initial acceleration period of each gear, with the throttle open just a little, the van jolts and doesnt pick up speed as expected. It can be made to stay jolting/kangarooing without picking up speed. When floored, it takes off (but neither as strongly as you would expect from an 1800, and it seems to struggle to get over 100kph).
My carbs have been apart, tuned, cleaned, checked, etc... I think this is a problem with the distributor, but i'm clutching at straws now.
The dissy is a single vac with elec ignition... number 021-905-205P... Old volks home suggests this is a 76-78 2litre dissy, but i have a feeling it should be compatible (are others running single vac dissys on these engines?).
I have been correctly timing this at 7.5deg BTDC, and have watched it advance smoothly with the strobe up to a max of 28deg advance when revved. The vac advance works fine also.
When driving, it feels to me like the timing is too far advanced... but i dont understand how this can be. I had a go at retarding the timing a little and it smoothed it out a bit but the power was lacking.
Any more suggestions/ help? What dissys are others running on these engines?
I'm going insane (we've almost put him up for sale several times over this, but i'm trying to hold my nerve!)
Sam
Hi , 28 Deg Total sounds a little low for a type 4 motor .
But
Also you might think I'm crazy but how old are your rear Tyres ?
Are they still round?
cheers
i run a 009 on my 2L. is there any wear on the dissy shaft ie can you move the shaft sideways. hows the condition of the base plate in it
“We all pay for life with death, so everything in between should be free.” Bill Hicks
the chaos project - click me
Tyres are in good nick, wheels are square
I mean round 😀
28deg is the mechanical advance only.... the vac advance is added on top 😉
There is a little wear in the dissy shaft but as i said its on electronic ignition so the timing mark is very consistent.
This may sound like a dumb question but which bit is the baseplate and how do i check its condition? I've taken this dissy apart completely and cleaned it all up in the past.
Sam
[ Edited on 19/7/2006 by Samblers ]
the baseplate is the plate under where the rotor goes that controls the advance
“We all pay for life with death, so everything in between should be free.” Bill Hicks
the chaos project - click me
Check the dwell , is it steady? (that will eliminate the base plate thing)
Type 4 can take up to 34 deg total mech ! vac hose disconnected , sound like the mech advance may be a little lazy
Theres two plates under the rotor on with the little/ball thingy at the top and the bit in the bottom where the weights sit. What am i looking for? Wheres the wear?
I dont have a dwell meter... doh
the mech advance is working to spec according to the old volks home website... shouyld i try advancing it more ???(others have told me that 28deg is the max mech advance for these engines)
S
this site is good for a general overview of checking and rebuilding a bosch distributor
http://www.glenn-ring.com/010/
ok reading straight out of the gregory's manual
uneven wear on distributor cam
faulty ignition coil
vaccum advance mechanism sticking or excessively worn
vaccum advance unit inoperative
the only other help i can offer is to try and buy or borrow another distibutor and test it in the van.
good luck your determination to persevere with this problem deserves a win.
I have the same problem it seems. Does it go away mostly when the engine is hot?
Cheers
.
No, its worst when the engine is hot! When its still on the chokes it runs a bit better!
Will report back in a bit 😉
Had a similar set of symptoms yonks ago. And after checking vacum hose from dissy to right hand carb, Current to carbie solinoids (really important).I guessed it must have something to do with that 30 year old distributor. I posed the question?,Do I continue to drive whilst the engine stammers through t intersections and when forced to overtake? or eliminate one problem on a long list of to do's.
After inspecting an empty wallet I eliminated the distributor as the possible source of my troubles and decided to focus on possible soutions within my budget.
Three more days followed of intense technical research followed and wishful thinking that perhaps come morning my beloved bus may have, during the night, cured itself of all its aliments and I would not have to contemplate the likelyhood of a brake down and subsequent tow equivlent in cost to a new distributor!
2 brake downs in peak hour traffic later( both physically and mentally), everything clicked. KONDENSOR.
And for a while at least I had revived my big loveable dud.
and my Ta"uschung Iron clad once again.
Excellent reply dude...
except i dont have a condensor!!!!!!!! (electronic ignition doesnt need them!).
I will stick it back on points again and see if that helps though 😉
S
:o Alrighty then, Get ahold of a Gregorys manual for your bus. I know they aren't the most comprehensive manuals ever written. However turn to the carbies bit. Its quite clear and has the least amount of contradictory terms for a single object in one paragraph. do that bit. but make sure you've done all the other bits before that bit,to make sure the crucial bit counts. Do the crucial bit properly using all the right stuff. Or that will bugger up all the other stuff and well.... I suppose, you'll probably have to get the bus?
Oh and if that proves futile, Its time to assume an advanced yogic position under the bus and replace the busted fuel pump diaphram(assumeing your running mech pump). You'll need 12 point key to suit as the top bolt is frankly a shit to remove with the engine in and the bus on the ground. A good idea is to remove the bottom fastener on the warm air stove pipe to the air filter so you can get a turn on that top bolt.
and if that fails take the bus to a mechanic, They will sort it out,decide if they like you and charge accordingly.
maybe i'll just set fire to it ?
No, by doing that you may throw the entire East/West coast vw equalibrium out of balance. Resulting in an Affront to the Great volkswagen gods.
thus bringing down their vengeful wrath in a dark and dreadful time of annoying car repairs which will plaque us all and will continue until such time as you, and only you have conquered this infernal...?, "hiccup", in an otherwise realatively careing relationship you seem to have with the Van.
Ps, Dont curse them or threaten them. It hurts their feelings and they always have their way in the end.
Sure you'll feel great for amoment or two, But then it will dawns on you that, Betsy or Mertle or Bud or whatever has had the last laugh as you realise that in your arson frenzy you've left your house key in the ignition and wallet on the dash. And the volks gods will look down and frown upon their once faithful deciple and how silly he looks on the long walk home with the empty jerry can.
I admire your wisdom dude... and your spare time 😉
Where's the matches?
REPLACE YOUR FUEL FILTER!!!!! Happened to me in the beetle, easy fix..
"Tell him 'We've already got one'"
the jolting ride between gears on acceleration suggests the accelerator pump is not squirting enough fuel. the only other thing to check are the vaccum lines including the one to the brake master cylinder i have replaced the rubber part of that line on 2 of my kombies because of cracks, hard to check because its under the vehicle up behind the rear passenger side wheel section.
I've had the same sort of problems with my 2litre kombi camper, i rebuilt the carbies replaced the solenoid valves, removed the choke plates (i always do that with solexes) replaced all the vacuum rubber hoses new plug leads and plugs new air filter then i started to turn out the accelerator pump screws and after it has fully warmed up it is very smooth on acceleration but never a world beater for performance.
at the moment it has a inlet valve seat gone on the no4 cylinder so i'm going to replace the head and then i am going to put a set of alfa 36mm webbers on it.
don't give up believe me when you strip these vw motors down to their innards they are very very simple machines.
Yup, have already stripped this one to its innards once, doh!
I dont think its the accelerator pumps or fuel related...I think the vacuum leak theory sounds like a likely cause (i havent checked this all yet cos its miserable outside!)... I'll give you my reasoning:
Say i'm cruising in 4th gear at 80kph. The throttle is JUST open so i'm slowing down slowly. If i veeeeerry slowly start to push the accelerator pedal down, to keep the speed constant, it kind of does nothing for a bit and then thats where it gets bogged and starts to stutter quite harshly.
Observations:
1. The speed hasn't changed so the MECH advance shouldn't have either
2. The accelerator pumps aren't in play because i havent stamped the throttle
3. The load on the coil/ plugs etc hasn't changed so they should be alright
4. What i should be getting is more VACUUM advance to get the speed going. I know the vac advance on my dissy works... so???
Are we agreed?
Did you check the FUEL PUMP DIAPHRAM ?
If it is split it will cause this type of impedement. ps, As suggested vacume hoses should be replaced.
havent, but will do 😉
Samblers wrote:Say i'm cruising in 4th gear at 80kph. The throttle is JUST open so i'm slowing down slowly. If i veeeeerry slowly start to push the accelerator pedal down, to keep the speed constant, it kind of does nothing for a bit and then thats where it gets bogged and starts to stutter quite harshly.
When barely under acceleration (cruising) the fuel swirls around the fuel pump and fuel still gets through.. When the fuel pump pushes fuel through the outlet under slight acceleration the outlet gets clogged with rust bits and shit from the bottom of the fuel tank and causes bad stuttering. Have a look at it, and it only costs $5...
"Tell him 'We've already got one'"
My VW guy says my fuel pump has low pressure (like 2.5 pounds when it should be 5)... so hopefully thats it
Start pulling it apart 😉
S
Fuel pump diaphragm had small split - replaced pump
Still runs shit
:cry :cry :cry :cry :cry :cry
Good. now with the air filter assembly off whilst running give the bus some throttle and make sure the accelerator pumps are working on both carbies. They should squirt equal amounts of fuel into the venturi.. Eliminate this. Then Re-tune your carbies start with the old worn out linkage, compensate, then go step by step. you would be amazed at the range of flat spots that can be acheived through the revs. If each step is not followed. A carbie synch takes out the biggest guess work In the equation. If not carbs then back to ignition, timing. Do a compression test and eliminate the valves/guides.
My 2L Kombi had much the same problems. I tried for ages to tune the carbies.
I went through all the checks
-vacuum leaks
-plugs
-coil
-points
-condenser
-leads
-timing
I finally fix my problem.
I replaced the carbys with other pair of another Kombi.
The carbies now on it are the dirtest looking carbies, but once I bolted them on, connected everything it run great.
Its like a different car to drive. I wish I had done it sooner.
Maybe hunt around for a second hand set of carbies.
Had exactly the same problem (hasnt everyone lol). Ended up being the throttle synchroniser. Adjust your throttle linkages (coming down from the cross bar). You want both throttles to move at the same time, otherwise one side of the engine will try and do all the work the whole time (run like shit)... its going to end up being one of those little things you thought it couldnt be... just slowly keep checking things off the list.
Well, my accelerator pumps are working ok, i know that... and its just been into my local air-cooled place and had a carb balance and settings tickle-up
It either ignition or carbs, but without seeing a fault in either i dont want to replace them 🙁
Never buying another dual-carb engined VW... twin port 1600 is the go
Don't give up. You will be all smiles when you have got it running spot on.
:P:P:P:P:P
