starting problem - 4TL 850

[Tripyrenees]

Right - I have rebuilt the head and put it back on. No real change other than the compressions have evened out a little better

4 - 10.4 was 9
3 - 10.0 was 11.2
2 - 9.2 was 10.5
1 - 9.2 was 12

The first test may have had some error but I am happy they are even'ish

So it just about starts but chokes and dies when gas is put down. I am thinking the carb needs a rebuild (although I did strip and clean it out with air)

Stumped a little.

 

[mr-reno-139]

Notice you are in France surely there must be garage local to you with experience of fixing R 4 as I am sure several of us on here would be able to help if we could get our hands on it
Of course we could all come over if you can pay our travel expenses ☺

 

[André4Renaults]

I'll get my coat.... (and passport!) LOL

 

[Tripyrenees]

Totally put you up

We have an old renault garage across the river. He has 4Ls , 4 CVs etc but half the time he is a little worst for wear, specially after lunch. His son has started working there now so it may get better and he works on his own 4Ls.

But that defeats the object of owning these cars.... Got to get it going myself with the help of you guys.

So on with the carb strip, clean and rebuild

 

[Tripyrenees]

So, I found a spare carb on my shelf, near enough exactly the same (just slightly different on the casting, probably an older version). Put it on, and after some tweaking, it started and runs well, albeit, the timing now needs adjusting. But it runs as it did, in fact I think better now I cleaned out the crankcase coolant sludge (sucked it out with a vacuum) and cleaned the head and polished the valves.

Cheers for the help everyone - if anyone does pass this way we do have a Chambres d'Hotes so your more than welcome

 

[Tripyrenees]

OK - still chasing my arse here.

Starts and runs but very lumpy. Checked timing with stroboscope and it is about right.

So when I pull the lead off each plug this is what happens;

1 - engine revs speed up
2 - engine revs drop near to cut out
3 - engine revs speed up
4 - engine revs drop and cut out

Now I have place the leads as per the haynes manual but not very confident in this diagram. Could I be 180 degrees out.

I tried the car on the road but it chugged along with zero power.

Cheers
Ian

 

[malcolm]

The order of the leads should be 1,3,4,2 going clockwise around the distributor.

Which lead did you have the strobe on? Either 1 or 4 should be good for a strobe.

 

[Tripyrenees]

Leads are correct

Timing set around 10mm in front of the pointer using the strobe on No 4

Revving the engine it sounds wonderful but when on the road it chugs along unable to get into 3rd as if it is running on 1 cylinder.

I am buggered if I can figure it out at the moment.

 

[mojobaby]

a few years ago I re-set my timing, (even though there was nothing really wrong with it). I tried to do it by ear and not according to the manual.
The car revved beautifully in the garage but when I took it for a test drive, I couldn't make it up the driveway. After a whole afternoon of trying to fix my "mistake" I turned the distributor while the engine was running, 90 degrees anti clockwise and suddenly everything worked perfectly.

The shaft has 4 protrusions which open the points 4 times per one revolution (as you obviously know). I was therefore 90 degrees out.

I still to this day don't know what i did wrong or how i got there, but i had exactly those symptoms that you describe

 

[mr-reno-139]

Maybe timing chain has jumped if the valves and rockers were seized

If you take no 1 or 4 plug out and rotate until you get top dead centre confirm with wooden or plastic stick in plug hole
Now remove rocker cover and check that rocker arms are rocking on end cylinder opposite to the cylinder the rotor arm is pointing to
Presume you adjusted valve clearances correctly?

 

[Tripyrenees]

Just stripped and cleaned out the fuel pump and blown air through the fuel lines just to make sure it is not a lack of fuel getting to the carb.

I need a new cap as I have broken it, messy about so much so that is first as my timing is everywhere at the moment. I will then double check the above, to make sure I am not horribly out with the distributor.


Cheers

 

[Tripyrenees]

Got the new cap and rotor arm.

I think I compounded the problem. The initial fault I think lies with the carb and letting in too much air (possible leak at the manifold or maybe the carb itself)

But when I got it started and running, I adjusted the timings but broke the distributor cap by twisting it instead of the unit itself (looking at the strobe light and not at the distributor). I thought it was fine but now it was not.

Put on the new cap and rotor arm and it started first turn without any vibration from the engine - took it up the road and it blasted away. I need to fine tune the carb and the timing and just seal the exhaust seal onto the manifold and I think job done.

Will also change the oil and flush out the cooling system again before my lad takes it back to Toulouse tomorrow.

Cheers everyone

 

[AntonioConceicao]

Just on time for 2015 :-) congrats