engine dies during warmup - 1.9

[croc]

Hi, I'm new to the T25, only had it a month, and have a engine problem that I hope someone can help with.

1985, 1.9 DG(? from original owners book) water-cooled petrol , 94k miles, Autosleeper high top.
Van is in very good condition, body and interior, but the engine appears more used than mileage suggests.

The problem appears to be carburettor based.
Engine starts and runs well from cold on the auto choke but during mid-temp range of warm-up it dies without warning if stopped at intersection etc. When engine reaches operating temp all OK, idles smoothly.
If the vehicle is kept on the road during the full warm-up, its OK through the mid temperature area.
I have removed carby and checked jets and drillings clear but no change in engine operation.

The wiring in engine compartment has been 'modified' and there is no power to the intake manifold heater - could this be the cause??
Carburettor is a Solex 34 PICT 5.

Another question - stripped sump plug !! What is the thread on the sump plug? I will be fitting a helical insert.

Thanx for any help
jon (croc)

[ermie571]

Hi croc,
there were some posts a couple of months ago on sump plug. Use the search facility and that will give you all the info you need!

Welcome to the club.

Em
x

[CovKid]

Could be a tiny air leak in carb (or inlet manifold) that seals itself once everything is hot and expands? On choke, the over-rich mixture will compensate. Usually if v-dubs die at intersections its weak mixture or an air leak.

[croc]

Thanks for the welcome Em! Found info re sump plug - don't know why I couldn't find it before!!
(croc supposed to rhyme with Dundee not 'old..)

CovKid - thanks, will try an air leak test with spray grease. There was a small vacuum leak between carb body and rubberised mount plate - have tried a smear of blue silicone there but will try more tests elsewhere.

Have some history with a LHD split screen, Aircooled during the late 1970's - drove UK and Europe including Austria snowfields and Grand St Bernhard Pass all on 6 volt - never had this sort of problem !! ah well.

[lambrettalee]

the "rubber mount" as you put it, is bonded, try rocking your carb when the engine is running,quaranteed it is split where the rubber bonds to the steel plate, that is a common cause of problems with that carb/fixing, every van I have had that used the solex carb has had this problem, I take it your engine is a 1.9wbx DF type, the rubber mount is available from brickwerks or your local gsf at about £23 , the 2 rear 10mm nuts that hold it down to the manifold only have to be undone slightly after removing the front 2 nuts and the whole carb and assembly will slide forward....

[Ian Hulley]

Check the engine number, this is on a flat part of the engine case just below the black breather tower ... the Pict was on the DF (lower powered) 1.9 WBX engine. A DG should have a Pierburg carb. Best find out what you/we're dealing with

Ian

[ghost123uk]

Might also be worth checking the short vacuum hose, that comes off the top of the inlet manifold on the nearside, for perishing whilst checking for inlet air leaks.

I doubt it is your actual problem, but it's quite common for them to go leaky and it can / does affect the smooth running.

[clartsonly]

I think oil is coming out of the engine breather and cutting the carb out that way, that is exactly what mine did.. clean the breather and the pipe if it has collapsed (floppy when warm) either replace it (expensive) or jam a spring in it to keep its shape (cheap). you might find when you take it off it is all white and gummed up, just clean that all out.


btw I have a hacked up spark plug as a sump plug, I think that is the common replacement if someone strips the sump threads.

[croc]

Many thanks for all your suggestions.
Have now tried or checked most of these items and will investigate the carb mount plate, again, today.
All other hoses etc as suggested appear OK, ie no change to the symptoms of the problem, so assume I haven't yet affected the source.

At some mid temp, over a couple of seconds only from running ok to stopped, it just starts missing and dies on idle - still.

The situation becomes murky as on checking the engine number it is indeed a DF with 34 PICT 5. Some time past has had a used engine fitted although originally it was a DG with different engine number. Therefore no history of current motor but appears mechanically OK with little blowby.

Is it worthwhile to source a used Pierburg and manifold??? Reliability and economy affected with the extra power??

Stripped sump plug issue - not being a great believer in emergency type fixes (but good to know), would rather take more time and fix properly. Less likely to bite back later at more inconvenient time! The plug location seems quite exposed to knocks so modified spark plug, as plug, would not lie inside protection ring. Therefore have sourced and fitted a M14 x 1.5 helical insert as a proper fix. Superb service and price from Uni-Thread, Totnes, Devon.

Thanks again
croc ;-(

[Ian Hulley]

Is it worthwhile to source a used Pierburg and manifold??? (

You'll also need to sort out a coolant supply to the DG manifold which your's doesn't have. Benefits are probably negligable given the low output in the first place .... cue the DF crew to protest the ear-bleeding power of said unit

[lambrettalee]

leave the solex , right carb for the motor and less grief than a pierburg imho,

[CovKid]

Just a thought, get hold of the end of the throttle flap spindle and see if there is any up and down movement. Its less likely than older VWs but is a known trouble spot for air leaks. If it has a lot of play, this may be the cause. The spindle can be reground and new snug bearings made to fit. Certainly on type 1 and type 2 vehicles, the dying revs was common with worn throttle flaps and its just possible that years of use may have worn it.

[clartsonly]

my engine is a df, and I replaced the rubber mount, it is very different to the dg version so make sure you get the right bit ordered (one is £8 the df one was about £23), did you check for oil in the air inlet? and the engine breather? try running it with no air intake connected at all to see if it runs okay?

(M14 x 1.5) this helicoil will be massive, I think the sump is only a few millimeters thick, I am no engineer but I think x1.5 make the presprung size 21mm long and once threaded in it will is supposed to be about 30-35 mm deep. Please correct me if I am mistaken, maybe I dont understand helicoils - I have only used them once to put in the exhaust and had to trim the M8 * 1.5 down as I couldn't get them cleanly down the 25mm exhaust holes.

I do agree with your comment about doing things properly though, although my spark / sump plug was in there before I bought the van 4 years ago and I have even taken the engine out and left it in, it provided an excellent point of swivel


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another thing I had with mine when it constantly cut out on idle was that the next time I started it after a long run (days / weeks later maybe) it idled fine, and only if I used it long enough for it to get cleaned through would it be okay, if I was simply starting it and leaving it running for 10 minutes on the drive then the next time it would fail.

[croc]

Back again!
Thanks to all, have tried spindle play, there is some on the choke ramp side but doing strange things to this while engine running at mid temp zone has no noticeable effect.
Another member has complete DG for sale so am seriously interested to change... but at 104k miles?

Note re helicoil inserts -
I may have not described these properly
M14 is the internal thread - ie the original sump plug thread, the tap is larger to accept insert, probably about 17mm diameter.
1.5 is the thread pitch - this also suits sump plug and is one of the standard metric threads.
The insert I used was 1D - one times diameter of nominal thread ie 1 x 14mm in length.
Sorry if original comment was misleading.

[clartsonly]

and you have completed the helicoil? when my springs were not completely in the threaded section then the bolts / studs would not follow them there is no way on earth that you sump is 14-20mm thick.

nothing wrong with 104k miles, at least you know it has been used. try and remember that the dg will need additional water hoses which will not be supplied with your df.