Running a bit rough

[politeperson]

My CIC 956cc 91' R4 is chugging a bit at idle. Annoying for a perfectionist like me.

It goes well enough though on medium and full throttle openings.

I have checked/replaced the points, done the valve clearances, replaced and gapped the plugs to no avail.

The car has covered 19,000 miles, I have recently awoken it after a long period of storage.

I did a compression test his afternoon. All cylinders are around 160psi.

I have checked the leads and the cap, all seems to be OK.

Anyone got any more ideas before I pull the head off?

 

[Eoynteenie]

Carbs ok? not full of stale petrol?

 

[DaveP]

Could be rust flakes in the float bowl, also worth checking the breather hose from carb to rocker cover, I think the 956 is supposed to have a 2mmish restricter in it, an 8mm rawlplug will often do though.

 

[politeperson]

Exciting Gasket Pictures

HI,

Love R4s, what other car can you take the head off in half an hour?

After wrestling the water pump off the head (2 seized bolts needed to be drilled), removing the studs etc. it was bare apart from the valves.

Decided to check out the urban myth of a dish washer as a parts cleaner. Secretly, after all the family were in bed I put the head and a few bits in.

After an hour an a half on max temp., the kitchen was (unsurprisingly) beginning to smell like the inside of a hot Renault 4 engine, so I abandoned proceedings worried that I would get caught and then divorced.

Opening the dishwasher revealed an immaculate head and bits. I then reset the dish washer to clean itself before breakfast.

This morning, smell gone, dishwasher clean. Looks like I got away with it. Shall not be trying it again.

I took the bare head (with valves) to my local friendly Mercedes garage (on a Sunday morning).

The engine looks A1, no bore wear, all very clean, no corrosion, backing up the low indicated mileage of the car.

I have noticed a split in the inlet manifold gasket (NO. 2) and another in the exhaust (No. 4). This wont help.

Checked the recirculation valve, it is present and correct, rubber pipes not split.

Whipped out the ex. and inlet at my friends garage of suspect no. 2 cylinder, slight pitting in the exhaust seat, but not much. Not much carbon.

Sorry no pics of the clean head, it has gone to be fettled.

The head is off to a small race car workshop tomorrow for new seats to be cut and refacing so I know it is A1 when refitted. Might get them to take a bit off for fun (anyone got a R5 GTL carb + bits?).

 

[alewis]

I'm sure your aware but thought I best say - careful not to turn the engine as you might damage the lower liner seals.

 

[politeperson]

Turning the engine

Thanks, I wont be doing that.

James

 

[Eoynteenie]

I'm sure your aware but thought I best say - careful not to turn the engine as you might damage the lower liner seals.

explain please?

 

[Steve Hennessey]

They are wet liners so they need to be bolted down when turning the engine with the head of. I would bolt them down anyway as when the block surfaces are cleaned up the last thing you need is to move anything.

 

[politeperson]

Steve,

I am going to bolt them down. Good advice.

Sure you haven't got a spare Hennessey Hop Up Kit for me?

Looks like this little car will be repatriated to Brive, so I have a bit oF a journey to do in it.

James

 

[pepper]

This does seem like an extreme way of dealing with a bit of chugging at idle!

Me i'd have taken the WD40 and sprayed it around the likely points (inlet manifold joints, carburettor base, etc etc) I'm sure this would have highlighted the points where air was affecting the tickover and saved a strip down of the engine?

I'm a great believer in if it isn't broken don't fix it, I have a friend who can't stop fiddling with his cars (Volkswagen camper and Morris Minors, he's had the engines tuned and fettled and they have caused him nothing but trouble! My little old cars only get fixed when they aren't running, otherwise I try and leave well alone.

 

[bantamallan]

I have been using the dishwasher for years, it gives a wonderful finish on alloy parts and just a light rust coating on steel, by the time the wash has finished most of the smell and mucky bits have disappeared. If I had room in the workshop I would put an old machine there.
Allan

 

[Eoynteenie]

guy at work does this, he said to soak the parts in old cooking oil over night(he drove a chip vat landie at the time so guess he had loads) wack it in the dishwasher and bam, nice clean parts.

And my dad did it once with an whole saab engine. Mum made him buy a new dishwasher as payback.

 

[Steve Hennessey]

Steve,

I am going to bolt them down. Good advice.

Sure you haven't got a spare Hennessey Hop Up Kit for me?

Sorry no spare hotup kits or even Hop up kits.

To hold down the liners use the head bolts and a lock nut and large washer on each. Before replacing the head run a tap down each thread hole and blow out and rubbish in the hole to ensure an accurate torque reading.