Bad vibrations...

rashmore · Post by **rashmore** » 04 Aug 2005, 14:43

What started off a number of weeks ago as occasional occurrence of vibrations at tickover has progressed into big vibes and serious lumpy tickover.
Its like when a petrol car has been highly tuned and it struggles to tickover.
Currently ticking over at around 900 rpm, if increase revs slightly vibes will gradually disappear. Seems almost as if it is misfiring
Sometimes when first start up almost like it is on three cylinders.
Not using excessive oil/water – always been a bit smokey on startup, and runs as normal once on the move.
Could this be dodgy fuel pipes/air getting in somewhere or likely to be more serious.
Pointers appreciated before I start the task of fuel line replacement/checking fuel filter for leaks etc
Cheers

wilkobob · Post by **wilkobob** » 04 Aug 2005, 15:29

Possibly a duff injector (had similar problem on bx TZD a few years back, and it turned out to be an injector, which was replaced wit one from a scrap car)? try bleeding the system at the injectors and see if it idles any better, if it does, theres air getting in somewhere. Is the fuel filter ok?

jeremy · Post by **jeremy** » 04 Aug 2005, 15:55

I agree with Wilkobob - try cracking open the injector pipes in turn and see if one is duff. (BE CAREFUL AND KEEP YOUR HANDS WELL OUT OF THE WAY AS THE FUEL WILL PENETRATE YOUR SKIN AND COULD KILL YOU).
Does the engine sound even when its cranking or does it sound uneven on one cylinder? This is a moderate indication of its mechanical health (valves, pistons etc)
Jeremy

rashmore · Post by **rashmore** » 04 Aug 2005, 16:20

Its always been a little lumpy on start up since i had it, but told by a couple of people that that not uncommon - mechanic up road, Uncle with same engine (pug 405). once ran for say 30 secs normally clears itself and off we go.
Once run for a bit and restart after break, starts fine, plus less smoke. but just been out in it and it was again lumpy start and blueish smoke.... lumpy rev band is from tickover (9) to about 12/13 then revs freely
Fuel filter changed a number of months ago. worth checking sealing ok.
Injectors - not worked on b4. Maybe daft question - how do i bleed ? engine off, crack open, press prime bulb to pump fuel, tighten, allow bulb to expand, crack open and repeat ? or other.
thanks

jeremy · Post by **jeremy** » 04 Aug 2005, 16:48

The injectors should be self bleeding if the engine runs. On old engines which were difficult to bleed the routine was to undo each injector in turn and operate the starter until fuel came out. If you were luck after 2 it would burst into life and you just treated the job as done.
These engines should start on about the second revolution with the starter and run smoothly on all 4 cylinders with virtually no visible smoke if they are running well. If they do not something's wrong.
Jeremy

Kowalski · Post by **Kowalski** » 04 Aug 2005, 17:16

I've not come across any injectors that were anything like self bleeding, I know the pumps are designed so they won't fill the injector pipes up with air if you run out of fuel but you still get air into them and it doesn't come out without bleeding. They might be self bleeding to a degree but they certainly aren't perfect.

rashmore · Post by **rashmore** » 04 Aug 2005, 18:16

Cheers will try the injectors at the weekend if can organise a helper.....
Just had look at car - just to confirm as not done this before- crack open nut on top of injector where metal pipe goes in to bleed pipes, being careful as high pressure, should pump fuel out. what are black rubber pipes that link each and return to pump ?
how to check injectors - remove assembly, stand back and crank over, watch spray ?
I did have the misfotune of running out of fuel(first time for everything...) - don't rely on gauge, use mileometer, but miscalculated -however that was months ago and was running fine straight after - could that be related ?
Cheers

jeremy · Post by **jeremy** » 04 Aug 2005, 19:21

Having got the car going it is nearly impossible for your problem to be air in an injector pipe. Yes you can have problems getting air out to get the engine going but once its going the problem is over.
The small pipes are the leakoff pipes. They harden and perish with age and if you have a Bosch pump you can have trouble with air getting into the system here but this generally shows up as bad starting. Roto-diesels just leak and smell but are otherwise unnaffected.
My own view is that your injectors are suspect and probably need overhauling. Cleaner may work but probably won't.
Jeremy

rashmore · Post by **rashmore** » 04 Aug 2005, 20:00

Hi Jeremy, black pipes make sense - got a Lucas pump. pipes are quite flexible, no signs of cracking etc.
So how do I determine if an injector is suspect seeing as will ave to be careful due to pressures ? crack open and see if it makes a difference to running - if not then duff injector ?
Cheers

jeremy · Post by **jeremy** » 04 Aug 2005, 20:26

Have a look at this link - there are further links to CAV pump overhaul and also to injector overhaul manuals which will give you some idea of what is involved. It is not usually considered DIY work.
http://users.skynet.be/sn/manuals.htm
CAV = Lucas = Roto-diesel which evolved to Delphi. The strange part here is that Delphoi is the rump of the old AC Delco components which was a GM company spun off in the late 80's or something - then bought the pump made by their competitors Lucas!
Jeremy

rashmore · Post by **rashmore** » 05 Aug 2005, 13:31

Been confirmed as duff injector(s) or maybe even a tight valve. Recommended to test each injector - ie crack open fuel and observe. once found which one- -check valve clearances on that cylinder.
Think i might do it the other way round as then do not have to wait to cool down again, plus know clearances are ok anyway.
Now going boof boof boof out of exhaust and v smokey.
Is it recommended to replace all injectors or just the one ?
Cheers

jeremy · Post by **jeremy** » 05 Aug 2005, 15:56

Unless you think one has failed prematurely which is very unlikely - do the lot - the car will be transformed!
Jeremy

rashmore · Post by **rashmore** » 05 Aug 2005, 16:32

Thought that would be the case, right, time to find local supplier/reconditioner...
Thanks for asistance, hopefully sorted soon
Keep u posted
Cheers