rough running

Post by **eastona** » Thu Oct 04, 2007 8:19 pm

Even with it blowing between 2 and 3, compression would be compromised, because;-

on compression in 2, 3 would be on exhaust, hence lowering compression in 2
on compression in 3, 2 would be on exhaust, also lowering compression.

I know they both reach the top of the bore at the same time (hopefully

) but for different reasons.

I do (frequently

) stand to be corrected though.

Just because ignition components are new, doesn't mean they work. had that before, it pays to double check, put the old ones back on, see if there's any difference.

Despite what I said above, though, it is exhibiting identical symptoms to my head gasket failure a few weeks ago, just after I'd serviced, so I gradually put the old ignition components back on with no change in the condition.

skipped the compression test (a head gasket is cheaper than rushing of to halfrauds to buy a compresison tester

) and just ripped the head off. Cause - two burnt valves and a 3-4 head gasket failure.

still, it happened outside my house, so can't be too angry

Post by **bmcecosse** » Thu Oct 04, 2007 10:29 pm

Well - i'm running out of ideas -can only suggest as above - replace everything one at a time and see if the problem goes away! I really can't see it being gasket with these compressions - but if nothing else works - off with it's head!

Post by **chickenjohn** » Fri Oct 05, 2007 8:02 am

I still think its dirty carb as Steve has not stripped the carb and cleaned it by hand. Squirting cleaner into it does not get everywhere that needs to be cleaned.

Post by **chickenjohn** » Fri Oct 05, 2007 8:04 am

" have balsted carb cleaner through so hopefully it's all clean inside. "

hopefully! ;-)

Post by **steve4063** » Fri Oct 05, 2007 11:50 am

right changed the head it seemed ok and no change in the engine running since done.

took carb apart and cleaned dash pot completely float chamber pulled choke slider thingy out and cleaned with carb cleaner and a rag

o and i changed the condenser too

and yep you've guessed it still no change lol

this is drivin me mad.........

Post by **steve4063** » Fri Oct 05, 2007 12:50 pm

the only thing i can think of is the engine is shot......

because it has been sat for a longgggggg time and condition unknown
its still smoking blueish smoke as well so looks like its a new engine.
i'll wait until monday to see if anyone comes back with any more suggestions

thanks for everyone who's tried so far much appreciated

Post by **bmcecosse** » Fri Oct 05, 2007 1:11 pm

Try a different dizzy - the complete thing and cap and coil and HT leads.

Post by **chickenjohn** » Fri Oct 05, 2007 1:35 pm

steve4064 wrote:-"mixture unsure as its running so rough
-snip-
apart from cutting out it just won't run right sounds like its blowing through the exhaust popping all the time and no power. "

That sounds to me like there is a leak in the crank case ventilation system or the system is set up wrong. Is it a late car with a mushroom on the inlet manifold?? Or is the pipe between the manifold and breather system leaking or even missing or wrongly connected to the air filter?? or even the wrong oil filler cap- see Willies post.

This could cause permanent weak mixture giving the bad running and the crankcase pressure causes blue smoke due to oil forced past the piston rings.

Post by **chickenjohn** » Fri Oct 05, 2007 1:40 pm

The mushroom has a rubber disk inside it as part of the breather valve/emissions system, the disk can perish causing air leaks and poor running. New disks are available!

Post by **steve4063** » Fri Oct 05, 2007 2:20 pm

there is a breather coming out of the top of the rocker cover into the back of the air filter the rubber is a bit perished.....

and there's a pipe coming out of the side of the engine which is just dangling that smokes also.

Post by **chickenjohn** » Fri Oct 05, 2007 3:05 pm

Is there any kind of blocked off pipe, a take off point, a bolt blocking a hole or other device on the inlet manifold between carb and cylinder head?

Post by **steve4063** » Fri Oct 05, 2007 3:38 pm

nope not as far as i can see anyway

just checked the pipe from rocker cover to air filter it had water in it but was clear and whole

covered up pipe and air filter holes and she just cut out

Post by **Axolotl** » Fri Oct 05, 2007 3:55 pm

Did it run any smoother with the pipe disconnected, before you covered the holes?

It sounds like it is relying on air from that breather pipe to weaken the mixture enough to run.

Water in that breather pipe will probably be condensation because the engine is being used for a lot of short trips and never really gets hot.

If that's been going on for some time, the chances are you'll find "mayonnaise" (a sort of creamy jelly-like substance where the water has mixed with oil) inside the rocker cover, and possibly inside the crankcase as well.

The rough running could be because its a running a bit rich anyway, and the breather pipe and possibly the crankcase breather is pretty gummed up, and occasionally blocking with the water / mayonnaise that's in it.

Suggest you take the rocker cover off, together with the crankcase breather pipe (I think it just bolts on to the side of the crankcase), and clean them both out with some petrol, making sure there's a clear passage through for air flow.

Also, try to replace the rubber pipe that runs between the rocker cover and air filter, and finally, weaken the mixture by turning the carburettor jet adjusting nut up a couple of flats (clockwise).

Post by **chickenjohn** » Fri Oct 05, 2007 3:55 pm

I think its probably not breather problem then. As far as I can see, all other avenues are exhausted- the engine must be completely knackered. Poor rings combined with extra friction from knackered bearings. Possibly even a broken con-rod causing the rough running (one cylinder down). Have you tried removing the plug leads one by one when the engine is running to see if one makes no difference?

Post by **steve4063** » Fri Oct 05, 2007 4:00 pm

tried removing leads no dif

had rocker cover off today when i done the head no mayo anywhere apart from in the pipe just a smidjen

it's been sat for a longggggggggg time hence why dvla don't have any record of the reg so been off the road before the 80's

there was 2 blocked water holes in the head very rusty so cleared them but i had noticed the rad gets welllllll hot at the top but freezing at the bottom so maybe its still blocked somewhere and the water can't pass through.

the gearbox when i checked the oil had loads of water in it oil was white so drained that and filled

it was sat outside with no windows doors etc so water was prob getting in everywhere it shouldn't

i have tried to run it for a long time but it smokes so i don't like to upset the neighbours too much

and no it didn't run any better/worse when i disconected the breather pipe.

i personally think it's a new engine as well

Post by **eastona** » Fri Oct 05, 2007 5:42 pm

did you ckeck for bore wear when you had the head off?

sounds like the same breather system as me (mine's a '69 1098).

If the breathers were shot, it'd be a bit temparemental, but not as bad as it is.

if it's it's breathing that heavily I'd suggest really knackered rings/bores.

I presume you checked all the valves when you had the head off? Good seats and no burnt ones?

Broken rod did occur to me too...I've had one start (quite well actually) and run (although very rough) with a broken rod. It wasn't hard to spot though, jutting out the side of the crankcase

all of the pistons did go up and down when you had the head off and turned the engine didn't they?

replace all the ignition components including plugs...(then hire a skip.

)

Post by **bmcecosse** » Fri Oct 05, 2007 7:15 pm

Well - it gave 4 poorish compression results - so i think the pistons are moving ok! If it's smoking that badly - and not clearing up with a bit of running - then I guess the rings are bound up on the pistons. You could try injecting some diesel into each bore ad leave to soak into the rings for a day or two - sometimes frees them off. Otherwise - head off again - sump off - and pop the pistons up and out for a look see doesn't take long and will tell all.

Post by **chickenjohn** » Fri Oct 05, 2007 7:41 pm

Yes, BMC could be right, sticky rings- makes sense- could also leave red ex soaking in there overnight.

I would suggest and engine flush but that might reveal other leaks etc.

Post by **steve4063** » Fri Oct 05, 2007 7:48 pm

i've got a full bottle of redex
do i just wip the plugs out and stick some in there i'll do that in the morning and leave until mon am

how much shall i put in?

Post by **MoggyTech** » Fri Oct 05, 2007 7:54 pm

steve4063 wrote:i've got a full bottle of redex
do i just wip the plugs out and stick some in there i'll do that in the morning and leave until mon am

how much shall i put in?

I'd go with diesel rather than Redex which is a top end lubricant. Also if this works, remember to do an oil change ASAP. Gut feeling is you need a new engine though