lumpy 1256

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Postby Wyke » 05 Apr 2006, 21:54

I`ve now done the dizzy cap, points .cleaned carb and new diafram.Plugs and checked leads but it ticks over like a bag of bones.
Seems to be a spark at no 2 but removal of lead on tick over does not change the running. Pulls away when I rev but rocks on mountings on tick over. Not sure if valves stuck in mub 2 so did a compression test.

I have managed to keep it ticking over and driven up and down cul-de-sac where I live to get engine warm. Then did compression test.

1 - 140 lb per inch
2 - 130
3 - 160
4 - 160

not sure if this is normal but it does seem to point at numb 2 cylinder again. Could anyone please advise.
At high revs under load it does pull away nicely but rocks in an uneven manner on tick over still.

Could it be head gasket ?
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Postby Chevette_Rwd_Beast » 05 Apr 2006, 22:10

I think your first guess was right mate, possibly a valve thats stuck

my brothers escort did this! until it let go the other night....

ticking over the engine rocks like a boat in a storm :shock: then it wouldn't tick over right, it was always ticking over fast, ended up there was a burnt out inlet valve that was cracked and chipped, my brother changed carbs,dizzy,coil,plugs,leads,points, before finding out it was only running on 3 cylinders once you took off the lead to cylinder 3 the tick over didn't change and the compression was down about 30% I think it was :? not positive tho

it was a engine builder who found out the problem for us, so I'm not sure how to tell which valve is nackered

hope this helps

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Postby Tortron » 14 Apr 2006, 07:05

possible valve regrind? or gasket

sounds much the same as what mine was doing.... back in the days when it ran
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Postby Chevette Girl » 19 Jul 2006, 03:21

Actually, that's about what my last compression test looked like, there were two high and two lower that were in line in the firing order, I figured they were what gave my engine its little wobble...
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Postby Doive » 19 Jul 2006, 08:35

Sounds like 1 and 2 are slightly low, as has been said a stuck valve or else a breach in the head gasket between 1 and 2. If you just had the rocky idle I'd take a look at leaks in the inlet system, mine idled like a washing machine full of spanners and I found one of the vacuum pipes was loose.
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Postby CR500Dom » 19 Jul 2006, 18:32

Check the valve clearances first :roll:
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Postby Wyke » 19 Jul 2006, 23:15

Checked valve clearances and all OK.
Spark at Num 2 - but no combustion.

Only thing I have not changed is dizzy and coil.

Very sooty spark plugs.

Beachy Head !!
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Postby Neilyman » 20 Jul 2006, 08:48

Did you check for play in the dizzy bearing as I suggested in your `misfire` thread?

Could still be the gasket though, only a couple of hours job to change, & can`t do any harm to replace it.
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Postby Wyke » 20 Jul 2006, 23:16

I have messed about with the points but always seems to be num 2. I am considering getting a recon dizzy as afinal check before I remove head. 2 days for me - not a few hours !!!

do I adjust carb first to try and get rid of sooty plugs ?
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Postby Neilyman » 21 Jul 2006, 07:28

Wyke wrote:do I adjust carb first to try and get rid of sooty plugs ?



I`d cure the misfires first, then do any `twiddling` as sooty plugs could be a result/symptom of your problem.
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