t25 running lumpy / kangaroo

[wayno]

oooh right where do I start.... thanks by the way for all your suggestions, ive checked the cone shaped filter, clean. Didn't know you had to depress the accelerator fully to reset the choke
ive not looked at the choke mechanism spring yet but I have sprayed wd40 all over the pan to check for any advance or change of sound, none.
The vacuum pipes from the pan to the carb and the one from the carb to the vacuum advance I changed when I renewd the vacuum unit.
The ignition module was changed as part of the refurb for a new one when she first failed, I put the old one back on and the symptoms still prevailed, maybe ive got two bad ones I don't know
Ive watched James Akers utube film and I can try that tomorrow. interesting enough he comments on another clip that on his van he "bunged the one off to the air filter and it ran fine
She has always run around the 900 mark give or take 100 even starting from cold
Keep giving me ideas and ill keep trying
Wayno

[wayno]

Hi guys, just a quick question, when the Haynes manual talks about possible air leaks around the manifold inlet pipes as a possible cause of engine stutter what exactly is it referring to
Wayno

[silverbullet]

That means the gaskets between the manifold and the heads. They usually fail to seal if re-used when the manifold is removed.
This all sounds like classic carb servicing/setup of choke, which is often misunderstood!

Sent from my S60 using Tapatalk

[wayno]

Hi all, been working away, ive just got back to sorting the van and here's the latest update.
Stripped and rebuilt the carb using the brickwerks kit, no change to the running performance ( incidentally the diaphragms and seals were in remarkable condition given the vans age, I'm sure they were all the original)
Compression tested and all found to be around 9.5 bar, rising quickly to pressure.
Checked the timing using the strobe light A>OK.
Went to the trouble of loaning a known good pierburg just to check and make sure id missed nothing, fitted and still running lumpy when getting up to temp.
Loaned one back off and my own refitted.
Question...... Has anyone ever had a problem with the coolant temp sender unit, the one fitted at the back and under the thermostat housing which might have caused a similar sort of problem to the one ive got.
Its only with hindsight and thinking back to just before the problem started i noticed that several times when out the temp gauge seemed to have a mind of its own, sometimes it would read normal and other times it looked as if the temp was cool with the needle hardly moving from the base point even though the engine was well up to running temp. Just a thought
Finally without starting on the engine ive got just as far as i think i can goooooooooo
Regards
Wayno

[937carrera]

It's a 1.9DG so there's no ECU for a coolant sender to message, so coolant gauge is irrelevant to the rough running.

So you've done a carb rebuild, all was in good condition and there's no change, so that isn't the issue. Did you check float level was set correctly ?

Tickover when cold is still 900 rpm. That's too low so should be adjusted, and how do you know what the tickover actually is?

Timing has been checked with Xenon, but have you checked the timing with all 4 spark plugs. Not to check the timing, but to make sure that when there is a misfire it doesn't coincide with loss of the timing light.

[wayno]

Hi there,
the van has always ticked over at round about 900-1000 rpm and up until the present issue has run with 0 problems, I could try increasing it to see if it makes any difference. (would that involve the co screw at the bottom of the carb?)
Thanks for the info re the sender unit, saves me a job and £8
I only connected the strobe to the No 1 cylinder HT lead to check the timing as per the Haynes manual and the mark on the crank pulley and the split in the block lined up, ive still got the light so il test all 4 when the issue starts.
I get allsorts of advice from different people as you would expect and most of it seems relatively logical, someone has even suggested either, worn cam lobes or tappit issues brilliant, by the time ive finished the old van will be a new van !!!

[937carrera]

Hot tickover at 900 is fine.

As others have said, a cold engine should tick over at around 1800, then drop fairly quickly. If yours doesn't the cold start enrichment isn't working.

The "CO screw" is fuel mixture, not idle speed, but I don't have a 2e3 carb so check the Sir Adventure advice I linked to earlier

[wayno]

Hi all
think ive finally got it !!!! Hair line crack in the servo vacuum non return valve fitting where it connects to the manifold. It was only by chance that I noticed the fitting was a little slack when the engine was nicely warmed up. Took it off ( I can hear you all saying " are you telling us you never tried that ) and someone had wrapped sticky tape tape around the manifold vent to replace the original rubber seal. It was only opening up when warm and it expanded creating the vacuum leak, Off with the lot, a friend had the non return valve fitting and ive modified the rubber seal to suit and a proper clip fitted. This morning tried it on a run
Looks like were back in business, it seems to have been a long journey with everything ive done to it since 19th Aug but its been worthwhile. Ive learned so much about the bus and how it all works and with your much appreciated suggestions and ideas finally got there,
The adventure starts again from next weekend so if you see a very happy chappie and his wife singing and smiling (A LOT) whilst driving along give us a big wave
Thank you
Wayno

[jrt]

Harrah!
David.

[937carrera]

Great, well done on finding that and posting the solution - no engine rebuild needed



Happy travelling