A strange problem

[Goswell]

I wonder if someone could offer some advise.

I changed the rocker shaft on my 1970 TR6 as I felt it may have been the source of some tappet noise from tappets 11 & 12.

Little wear seen but some rough surfaces.

Injectors refurbised and balanced, thanks to Mike Bilney, as No 5 was running rough.

Started her up only to find no fuel on No 5, so changed the Banjo bolt and I now have good spray patterns on all injectors.

 

Now engine runs rough, as in sounds like a diesel, deep routed rough sound and at tick over engine rocks more than usual.

Tends to clear at higher revs and doesn't deliver power at low revs, so clearly isn't right.

Starting from cold is a real struggle,

 

So I have now re checked and reset the valve clearances, timing is perfect using a timing light.

Wondered if I have an electrical fault so changed the distributor cap and rotor arm.

Plugs look ok, colour wise, and checked the spark on No. 6 with plug out.

 

I'm wondering if the tappets are getting stuck, seeing as it is a new shaft, though no evidence when cranking by hand.

I've driven for about 10 miles max with no sign of an improvement.

Could I have an ignition lead problem or a plug breaking down ?

If when I removed the metering unit, to change the banjo bolt, could I have miss aligned it when putting it back. Having done this at TDC with no need to rotate the metering unit I cant see how it could have rotated and I presume it would have to rotate 180 degree's before being able to align with the distributor. if it's 180 degree's out would the engine run at all ?

 

Food for thought, I'm off on hols for 10 days and will only have one day available to fix if I'm to get to Harrogate.

Will greatly appreciate your inputs.

 

I'm going to order a new set of leads and plugs anyway, just in case.

 

Many thanks in advance

[Peter Cobbold]

That rough sound (a 'hollow'sound to exhaust?), the engine rock at tick over, difficult cold starting, and running OK at higher rpm could all be caused by over-retarded spark timing. Set it static to 12BTDC with 12v bulb across points and go from there.

MU timing not critical.

[TRTerry]

I once set my valve clearances to the book figure having forgot that I needed twice the clearance as the cam was a high lift cam ( fast road use). The engine turned, but sounded very wheezy, almost reluctant. Could this be a possibility?

[roy53]

With regards the tappet noise, i changed two complete rocker assembly's trying to get rid of the same noise and had described that it was engine strip down time to investigate when the speedo cable broke fitted new cable noise gone . Won't solve your other issues but check it out.

ROY

SORRY MEANT REV COUNTER CABLE

Edited July 15, 2011 by roy53

[rpurchon]

plug leads mixed up