1975 Renault 6TL

[vulgalour]

I'm beginning to think that's what I've done. I've also learned tonight that those pipes need to be connected or blocked or the engine won't run for reasons I still don't really understand but accept. Really, that's all my French car ownership in one phrase "I don't know why this has to work this way, but okay!"

[ekjdm14]

That's often the best way if you don't fully understand something, just accept that it works the way it does and then gain more of an understanding of how it works, when it's working... If that makes any sense lol

[Zelandeth]

Managed to get the distributor cap on my first Saab on 180 degrees out first time I changed it - the resulting fireworks and deafening bang that resulted when I tried to start it scared the living daylights out of me!

So close to having it going now...

Several bits of the vacuum system on my Lada (and it's wiring...) definitely fall under the "I have no idea why this is set up like this, but it needs to be that way...So okay!" so I can associate with the head scratching which can accompany some odd design decisions.

Let's not even get onto how the warm-up regulator on the Saab regulates fuel delivery (hint: it increases fuel delivery when cold by *decreasing* the delivered fuel pressure). That really made my head spin the first time I looked at it.

[mickeymoon]

Let's not even get onto how the warm-up regulator on the Saab regulates fuel delivery

If it's the same as the one on the Bosch injected 1987 900 T16 then "extremely badly for a car designed in such a cold country" is the answer.

[Zelandeth]

Nope...That system is electronic - the one on the old 8v cars is all mechanical.

[vulgalour]

Bluh, well I know *I* couldn't design a fully functional car so I have to believe Renault do in fact know better than me on this one, whether I like it or not.

---

An American once told me "to assume is to make an ass out of you and me". Not sure what I was doing at the time to warrant the statement, but they're words to live by nonetheless. It is with this in mind that I approached the engine in the Renault today. It's entirely likely that by assuming I've done things properly I have, in actual fact, done them wrong. So, established conventions and sound principles out the window, let's do everything by the workshop manual (not a Haynes one) as if I've never, ever seen an engine ever before. I'm going to be as in depth as I can be so if you see anything really wrong that I've done then you can point it out to me as we go along.

First of all, fight with the gear lever extension and lose one nut. Then fight with the rocker cover and the spark plug for cylinder 1 at the front of the engine until you can see what you're doing, like so.


The manual, it says:




I will state that at this point I set it to TDC according to the sound principle of putting something in plug hole #1 and slowly turning the engine until the something reaches the top of its travel but before it crushes said something. That gave me this, which is wrong.


Instead, I did it by the book and a fraction of further movement of this.


Got us here. Which is correct, nes pas?


Good. Then the weather started kicking off, typically, blowing the manual and tools all over the shop and occasionally raining in my ear. So this was going to be fun. Now, the next thing to check was the distributor which was suspected to be installed incorrectly. On removal of the distributor via the awkward clamp nut that I haven't got a C shaped spanner (that's the shank of it, not the head) to make life easier with, we can see the drive cog down in the hole.


The manual says:


So that's wrong. I pulled out the cog and replaced it about three thousand times until it was as the book described above, like so.


Then the weather kicked off and blew the manual into my rapidly cooling coffee nearly throwing it off the roof and, well, I got a case of all the nopes. You'll notice as well that I need to remove the drive cog again because I've actually put it in the wrong way around with the 'fat side' towards the bulkhead rather than towards the headlights. Luckily Mike spotted that in the photographs. To finish off I hastily put the tools away, dropped the distributor and clamp back in their respective locations and shut the car up for the day.



It's not a lot of progress because I only had about 90 minutes spare, I was being methodical and the weather was being a big old crybaby at me. Next time I'll try and get the distributor drive cog, distributor, valve clearances, points clearance, distributor cap, spark plug and spark leads all back on. I might even have enough time to fight the rocker cover back on and find the nut that ran away.

[demag]

My take on this is as follows:
1, I think your crank is timed up correctly at or near to top dead centre on Cylinder No.1. looking at your pics. I assume No.1 is at the gearbox (flywheel) end. i.e. nearest the headlamps farthest from the windscreen.
2, If No.1 is on compression stroke the valves are closed and the rocker arms should be loose and you should be able to "rattle" them with your fingers. If they feel tight then either they are adjusted incorrectly or No1 cylinder is actually at the other end nearest the windscreen (doubtful but possible). So before you do anything else see if the rocker arms on that cylinder will "rattle".
3, Assuming No1 is indeed at the flywheel end and the rocker arms "rattle" we now know that cylinder is on compression/firing stroke. So, when the distributor is fitted the rotor arm should point to the brass terminal that has the plug lead from No1 spark plug.
4, Now turn the engine 180 degrees. The next cylinder to come up to compression will probably be No3 assuming a firing order of 1-3-4-2. Run through the same procedure on that cylinder and the remaining two cylinders. Refit the rocker cover.
5, Some of those small bore pipes look like they run into the inlet manifold at the base of the carb. I think if they are left open the mixture will be much too weak to run so blank them off for now. Shove a bolt in the end and wrap some insulation tape round them.
6, Turn the engine so that the points are on the distributor cam. I don't know what the correct points gap will be but 15-20 thou should be enough for a good spark. Fit a new condenser. You could be messing about for ever but it will never run with a duff condenser.
7, Tip an egg cup full of petrol straight down the carb then open the throttle once and let it close. You now have enough petrol in the inlet manifold to fire the engine.
8, Ignition on and spin her over. Something should happen even if it doesn't run it should stutter or make some attempt to fire.
9, If it runs, MAKE SURE YOU HAVE OIL PRESSURE! iF NOT STOP STRAIGHT AWAY. If it runs but feels "lazy" even with a bit of throttle then turn the distributor to advance the timing but just a few degrees.

Once you can get it running under its own steam even if it sounds pretty rough everything else becomes secondary because it's all down to fine tuning then.

Good Luck!

[vulgalour]

After making the update today, the general consensus does seem to be I'm 180 out on my timing and have been trying to get the engine to run on the wrong stroke which is never going to work. What you posted above is nice and clear and does help me understand better what should be happening.

[vulgalour]

Update time! Ready for some frustration? I bet you are.

First job is to rotate the flywheel a full revolution to sort the timing out. It's just about impossible to photograph the valves, but this was the before shot (I think).


Check the distributor drive cog and find it's back to the same place it was. So that needs to come out and be turned around so the fat side is on the side it should be.


Made sure my timing mark was where it should be, like so.


Now, the valves are in a different position to previously, but again quite difficult to photograph.


Turned the distributor drive cog around so it's aligned properly. This was actually much easier than my first attempt so I guess I'm getting the knack of that.


I was asked which distributor is fitted, so here's the details for that.




Put the distributor back in and the rotor arm now points in exactly the opposite direction to what it did before giving the flywheel one full revolution. That's to be as expected, from what I understand people telling me.


I also put enough pipework in and an improvised bung for the vacuum/fuel thing under the carburettor. This now appears to be working properly as the sellotape cap was deformed inward on the pipe so must be creating at least some vacuum.


Distributor cap and leads refitted in the correct order, connected up to the coil, a little petrol down the carb, jump leads to the Rover because I'd forgotten to fully charge the Renault's battery and we tried again.


This is where the frustration is because I'm sure you'll want to hear I got it running allbeit badly and much rejoicing was had. What happened instead were a few weak pops in the exhaust rather than backfiring out the carburettor but not enough to get the car to actually run. A little more accelerant was applied to the carb and again we almost got it to fire but there is another problem somewhere. It does appear the timing is as it should be now, so that's something. Even with a remote fuel source we're getting fuel up to the carb but it's not getting through it, I'm guessing there's a blockage in there somewhere. There was some black gunge around some of these holes that were previously clean.


I plonked the air box back on because I was fed up of moving it every time I got in the car and decided to do this update to help me troubleshoot the potential problem rather than poking blindly at something I don't understand the cause of.


My suspicion is that there's still a blockage in the carburettor somewhere and the spark may be too weak to make use of what fuel is getting through or put directly into the carb. I will agree that it must now be something very simple to find, it's just going to take me a while to figure it out because of my lack of experience with this sort of fault. Please be patient with me.

On a happier note, the new dash clock arrived.

[Hell Razor5543]

Well, despite the frustration, you appear to be making progress.

[CitroJim]

Love the dash clock

That is just so cool!

[vulgalour]

TIME TOAD

[Hell Razor5543]

And if it can use the old, pre voice radio communications devices it would also be a MORSE TOAD.

[Stickyfinger]

A Frogold ?

[demag]

I think you're close now, it sounds like it wants to run. Popping in the exhaust is good, better than backfiring through the carb. There's a few things to check: condenser, points, coil and ignition timing. Even if the carb is not quite right, with a bit of petrol in the inlet manifold it will try and run. I think that is why it's popping in the exhaust, it wants to go!

The distributor is Ducellier, standard stuff back then so looks ok. That condenser looks as old as the hills (or the car ) Do you have a spare or can you get one? Car spares shops should still carry some stock I imagine. You probably won't get one for that engine but to be honest any one will probably do, even a Mini one which they might have. With a bad condenser you may well still get a spark but it will be weak and will not fire under compression in the cylinder. If you place a spark plug on the engine somewhere and and connect one of the plug leads to it then turn the starter the spark should be a strong bunsen blue colour. If it is a weak yellowish or orange colour that signifies poor primary ignition i.e. condenser, or pitted points or even a poor coil.

If the spark is ok try advancing the ignition timing slightly. Looking at your pics the rotor arm turns clockwise so turn the distributor body anticlockwise a few degrees and try the starter again. If you have petrol and a good spark it will try and fire. If it still just pops in the exhaust then advance some more. Keep trying until it either runs or kicks back in which case the ignition timing will probably be too advanced so back it off slightly.

Once you get close to the optimum ignition timing, even with a dodgy carb as long as there's petrol present I should think it will suddenly rev then die as it uses the petrol in the manifold. Of course if the carb is not as bad as you thought it might continue to run. Don't give up it's very close.

Ah one other thing. I have come across some engines that just do not want to run with the aircleaner off. The old Ford V4's were a case in question, if you could get them running they sounded like a ruptured pig and yet with the aircleaner fitted they were much better.