running on and on and on and on

[jond]

Hi as the title suggests ive got another mystery with my rocco ran it today for half an hour to check how it drives and found another issue when it was fully warm the revs seemed to rise to about 1800 rpm at idle then when i switched it of it kept running on sort of chugging really weird plus a burning smell from the exhaust previous owner(dan) said its been doing it for a while said its maybe a relay any ideas anyone its got a pierburg but i have to say it does run alot better than my last rocco with weber carb apart from the above mentioned problem thanks jonathan

[marcus]

Check the state of the plugs, if deposits build up on them they get and stay hot enough to ignite the mixture even though the ignition is off.

[mark1gls]

I guess the timing is out.

[go-for-it1]

Or running very rich which would also cause plugs and cylinders to be carboned up and resulting in running on.

[ianaudia4]

Very common on old series 3 Landrovers, usually running to rich!

[jond]

I will check the plugs tomorrow to see what colour they are , i have been reading about the shut off valve on the carb so will look at that as well, how easy is it to adjust the mixture on the pierburg

[james butler]

There is an anti run on device on the pierburg carb and if the vac pipe splits on it it doesn't work.
When mine had a pierburg the previous owner had cocked up the vac pipe layout and put a bolt In the pipe that should have gone on this device resulting in run on after the ignition was switched off.

[marcus]

See the first post in this thread for a link to the manual.

[old_school]

service check timing and fuel mixture

[jond]

Wont get much chance to play with the rocco as its now half term and I will be busy with the kids but I have had 10 mins to have a quick look under the bonnet first the plugs a quick check showed them to be very slightly sooty but not too bad then I removed the air cleaner to have a quick look at the carb all hoses look quite new but its hard to tell at the back of the carb I think I will remove it and give it a clean and check over also I will remove the waxstat to check it is working its the plastic type and looks quite new anyone let me know what its function is Also when I ran the car I noticed when warmed up and running for a while it would suddenly at idle shoot up to 2500rpm I have read about the 3 point valve thingy being a problem and the wiring to it does look dodgy this could be the cause of the over fuelling and running on!! maybe , will keep you posted on what I find out cheers

[go-for-it1]

Jon, by all means play around with it and do some checks but don't spend any money on it because you will, eventually, bin it and put a simple Weber on. Trust me, I've had 2 with pierburgs and had all the running/non running you and tens of others have had, and eventually binning the pierburg solved them all. Dont get me wrong, the pierburg is a wonderful piece of kit when it has not been fiddled with, but if it has then it becomes a bitch cos you don't know what has been touched or changed. I have the two pierburgs here in various states of assembly, and you are welcome to have them for free if you pick them up from Blackburn, but as I said they didn't run well so I don't know which bits are good and not.
Rob

[jond]

Still got problems with it Checked and repaired the wiring around the carb for now when its warmed up it idles at 1100rpm (too high i think) Does run nice with no missfiring But when i switch off it carries on running on(sort of chugging) the manifold warm up pipe to the airfilter is missing plus the timing belt seems very slack too me(not sure what it should be) i think i will check all the timing marks next and then tighten the belt adjuster (seems unfair to blame the pierburg for all the cars woes haha) Also the last owner mentioned a relay (no 61) fitted as part of the 3/4 unit that could be causing the running on issue I have also read online that i can by pass this (not all cars had it fitted) Any input would be great Thanks Jon

[mark1gls]

Timing belt should be able to twist if through 90 degrees when held with your finger and thumb. If you tighten it and the car sounds like it has a supercharger fitted its to tight.

[jond]

Right checked the belt 90 degree twist so all ok next removed the plugs very black and sooty so will give em a good clean they are also of the 3 prong variety though not sure if thats a problem next i want to check the timing i will borrow a timing light later this week but i want to check something first i have lined up the rotor arm on no one plug (next to the cambelt) with the small line on the dizzy body then checked the dot on the cam (inside next to the engine) but i am unsure about the flywheel markings i removed the cover and there is a pear shaped groove on the side of the flywheel i have read that this will be where i time it to it is suppose to be 18deg btdc does that sound right it also says that tdc is shown as a dot on the flywheel but i cant find it engine is ex 1.8 carb also what is best to mark the flywheel with so the strobe picks it up on the timing light hope the above makes sense to some one cheers jon

[the edmundator]

If the plugs are black, it's probably running rich and from the above comments that might be your problem.