1975 Renault 6TL - the fine line between brave and stupid

[Vulgalour]

I am stumped so I'm posting this info on all the forums I use for this car. This is going to be a simple fix but one that I can't figure out, I've just ended up confusing myself.



In the book it states there is a V mark on each of the sprockets the chain goes on. My engine does not have these Vs or if it does they are so feint as to be essentially invisible. Here is the helpful diagram (which is printed upside down for some reason)

Now, when I first timed this I did it to "the timing marks" as directed by the Haynes and got it wrong because I lined it up to the two marks I do have on the sprockets that being a dimple on the camshaft and a blob on the crank, as below. The crank is at tdc when the blob is at the 10 o'clock position, piston nearest the timing chain is at the top when the blob is at 2 o'clock and at the bottom when it's at 8 o'clock.

If you line up as per the book instructions, taking the blob/dimple to be an alternative to the V marking, you cannot get a full revolution of the engine, presumably because a valve is touching a piston or something, I don't know. I wasn't inclined to force it, I'm being very gently gently in my approach. An internet hunt was futile, I could find info on how to time jet engines and ECU remaps but couldn't find anything to help me with this, I just ended up even more confused.



So now I'm cold and frustrated both with the job and myself.

 

[André4Renaults]

I think (think!) I may be able to help here, as I've had this problem myself, albeit not with a Renault engine..... But here goes.... (& I apologise in advance if some of this is like "teaching one's grandmother to suck eggs) The crankshaft rotates at twice the speed of the camshaft sprocket so when you set everything up it's possible (I've done this!) to get the timing 180 degrees out. The section in the Renault 4 H.B.O.L. says much the same as the Renault 6 re: the marks on the sprockets, too, so, in the absence of this working one needs to go back to first principles. The marks MUST mean something, so might I suggest you put the no. 1 piston in the T.D.C. position I.E. fully raised in the cylinder and then see where the mark on the crankshaft sprocket is. The sprocket can only go onto the crankshaft ONE way, so wherever the marks are they MUST be correct. Rotating the crankshaft through one turn (360 degrees) would only turn the camshaft through HALF a turn (180 degrees) so it's now that the mistake could be made.

Whatever position the mark on the crankshaft sprocket is at when it's at T.D.C. IS correct, as you've seen that the pistons ARE at T.D.C., so forget the position of the crank, T.D.C. is when the cylinder next to the chain is at the top of its stroke, and you say that the dimple is at 2 o'clock, which suggests the crank is 180 degrees OUT in the picture, as the dimple is at about 8 o'clock. Once this is in position line up the camshaft by ensuring the mark is mirroring the crankshaft mark and count the number of chain links either side of the sockets to check; looking at your picture I've counted the number of teeth on the camshaft sprocket & they're different for each side, but I appreciate you may not have set this accurately.

It's not easy, but going back to basics can help sometimes! Good luck!

 

[Vulgalour]

I think that adds to what I potentially did wrong. The advice I followed is much as you've posted above and reinforces what I'd potentially done wrong. Little mistakes due to my own ineptitude, inexperience and lack of joy at working on engines. Thank you for taking the time to post the info. I really wish I knew why it won't go into my brain and stay there though!

---

Thanks to this post (which is the first one I read after posting the problem): https://www.frenchcarforum.co.uk/forum/viewtopic.php?f=5&t=49883&start=150 I got the timing issue resolved. I tried to take a video but... yeah. I'm going to need a helper to either turn the engine or hold the camera. And some better light. But anyway, it's turning by hand, things go up and down in an organised fashion now and it seems much better. It is, however, far too cold to do any more work in my poorly lit unheated little garage so a fuller update will have to wait.

To resolve, I removed the camshaft sprocket, unfastened the rocker bar enough that it as loose and turned the crankshaft until #1 was at TDC proper (not what I'd mistakenly called TDC, which was actually 90* out). I then turned the camshaft independently to watch the valves, as per the instructions. Once things were moving as they ought I checked the blob and dimple and they lined up as per the book. Cautiously, I put everything back together and gave the engine a few turns and it turn perfectly fine with the valves doing their thing in an organised way now as far as I can tell. I hope that means I've fixed it and I wonder if it was the rocker bar locking things as I'd not known or had forgotten that it shouldn't be tightened down until you've set the timing.

 

[Vulgalour]

With the engine hopefully timed correctly now there was nothing more to do than get things buttoned up. The weather has been changeable today so I got on with what I could before work while I had the chance. I figured out how to dismantle the front end on my own without removing the bumper or having bits of the car cartwheel down the drive, which was something. The key thing was pulling the face off, which was already unbolted just snagging on things because the weight of the bonnet was holding it when I tried to remove it. Bonnet off and it was much easier to do, easier to store the two pieces separately too.

Then the fun task of putting the engine back together. First off I had to slacken the bolts on the sump (which was a chore) so that I could get the rubber seal on the timing chain cover to sit in properly. Bolt the cover up nice and tight and then retighten the sump (which was a chore again) and that was this end good to go.

Then I could do battle with the belts which is also a chore. For the cam pulley to water pump belt you need to undo the cam pulley to jiggle the belt on and then tighten it all up again. Having the tensioner now working did at least make putting tension on the belt easier. Alternator belt was much easier as that's just a case of undoing the bolt holding the alternator so you can lift it, put the belt on and then effectively let the weight of the alternator tension the belt before tightening the bolt up again. While I was working on this side I got jubilees on both of the fuel pump hoses and tightened up the jubilee for the radiator hose. All the other hoses are easy to get to with the engine in the car. I also put the spark plugs back in and put the rocker cover on properly.

With all that done, the only thing left to do before fitting the engine back in the car is to remove the steering rack. It was too dark to see what I was doing and throwing it down so I'll do that bit tomorrow which is at least straight forward. Plonked the bonnet on and called it a day.

 

[Vulgalour]

My poor little blue trolley, it was never designed to cope with my bullshit.

It gained that war wound gallantly transporting the Renault's engine and gearbox to the engine bay so it could be battled into position. A late start and short days meant I didn't get as far as some and had to press on after darkness had fallen. Mike helped fight the last few bolts and such into place and Nugget the Corsa illuminated the scene.

It is in. Finally. There's one stubborn balljoint nut that won't be sensible *spinspinspin* and tbh, it was getting difficult to see what I was doing. Engine mounts and gearbox mounts need tightening up and the various ancillaries plumbing in so a test run can be attempted. All of these are jobs for tomorrow if the weather continues to be agreeable.



It's got to get easier from here, right? It's just got to.

 

[Vulgalour]

Today was almost momentous. Almost. The short version is here:

The long version then. Got all the various wires and pipes plugged in that needed to be to get the engine running, got fuel in the tank from the last attempt, got things timed to the best of my ability, stuck the key in and decided to see what would happen. Unfortunately, where before I had fuel and spark but bad timing I now have spark and good timing but no fuel. When Mike was available we hooked up the Corsa with some jump leads so we wouldn't flatten the battery, put a little bit of fuel in the carb and got a cough of life out of the engine.

I'll take the fuel pump off and take it apart. It's probably blocked or the diaphragm has failed so it's unable to get fuel to the engine room. All the electrical things that did work that are still connected still do work. Feeling optimistic and only a little bit frustrated.

 

[mojobaby]

Isn't that a great feeling?

 

[Vulgalour]

Would've been greater if it fired up! Still, it's a start. Tomorrow I realised taking off the fuel pump might not be the smartest move, it might be fine. Instead, I'm going to connect my spare electric pump (if it works) to the fuel line from the tank to check it's pulling fuel through. If it's not, we'll set up a gravity feed for the fuel to get it into the engine and see if that sorts things out.

Spark - I know I've got, the fuel we put directly in the carb did ignite, on all three attempts. Not enough to run the car though.
Compression - I know I've got, you can feel and hear it when turning the engine by hand
Timing - should be correct, it was checked so many times before the engine went back in the car
Fuel - definitely not getting even as far as the pump. There is about 12 litres in the tank and no petrol on the floor so I assume it's still all in there.

Just a bit frustrating I can't be out working on it right now but it's dark and frosty tonight so I'll just have to wait.

 

[Vulgalour]

Another day, another failure to get the car running. Sorry to disappoint there. However, I do at least know what was causing the issue with fuel not getting where it should. Because absolutely nothing was coming out of the pipe I did what I should have done ages ago and pulled the pipe off the sender and removed it from the tank revealing immediately the problem which is a missing filter bag and a completely clogged pick up line as well as lot of sludge.

I know, I know, I should have dropped the tank and flushed it all through and checked this before even trying. I didn't, this is the result.

It didn't look like rust, so I let it all dry out before doing anything about it and it now looks like it's covered in what I assume to be refining sand.

I'll clean it up as best I can so at least it can be used to suck fuel up if not tell me how much is actually in the car. The fuel gauge has worked, once, while I've had this car so I'm hopeful this can be salvaged. It will of course need a new filter bag too since that's either dissolved or rolling around in the bottom of the fuel tank somewhere.



With the sender out, I checked that there is definitely fuel in the tank, which there is, you can just make out the reflection of it.

Bought a couple of fuel filters, the only ones the shop had, connected one to the fuel line and dropped a length of hose in the tank then connected the electric pump to the other end to see if it would pull fuel through.

Unfortunately, the fuel line that runs the length of the chassis has a blockage in it somewhere. Mike's going to bring the little compressor home so we can blow the line through back towards the tank to hopefully clear it and we'll retry a start with the current fuel filter set up. If the old sender does clean up and work then that's great, I'll get it refitted. If not, I'll look for a new one in the new year, I shan't have the funds for one before then.



I'm getting, at most, 3 hours play time a day on this car and that includes any errands Mike needs to run me on to pick things up. It's really frustrating as I'd like to get a lot more done in a day, there just isn't time with the short nights and no space in the garage if I had the car in there.

 

[Vulgalour]

Right then, I had a go at cleaning up the sender to see if it was salvagable and I think it is. Once it had dried out, most of the grime was quite powdery, sandy stuff and could be literally brushed off with an old toothbrush and no cleaning agent. There is some surface corrosion to the mild steel components but nothing terminal. The tattered remains of the old filter bag completely disintegrated so I need to find a replacement but other than that, it's all good. The blockage in the pick pipe was quite minor too and cleaned out with welding wire, I then ran some water through it to check it was flowing freely, which it is, followed by some WD40 to make sure it was all dried out. The rubber sealing ring is still supple so should be reusable and the float is free moving and submerging it in water didn't result in any bubbles coming out or water going in so I assume they're both good. The float arm moves very freely now too. Usefully, the little square of orange you can see to the side is a removable panel that slides out of the main body of the sender so you can clean out all the sediment from inside it.

The float tang and the resistance wires (at least I assume that's what they're called) are all in surprisingly good shape with no corrosion to speak of and what corrosion you can see in there is just on the steel backing plate and looks worse than it is because of the flash and things still being a bit wet.

This stands a fighting chance of working I'd say, which I wasn't expecting when I pulled it out of the tank. I'll get the multimeter on it tomorrow (it's not here at the house) to see if it is actually doing what it should. If it works, the only thing I'll need to find is a small replacement filter for the pick-up pipe.

 

[mojobaby]

Presumably there's more of that sediment at the bottom of the tank as well.

Might be a good idea to check on the filter inside your fuel pump. If its the same as mine, its a quick job.

Someone told me once-"No pain-no gain". But you're nearly there!

 

[Jurjenz]

Aaargh, that´s very frustating, but keep up the good work! Thanks for showing your progress, I hope the engine will run soon!

 

[Renault4 Hat]

By far my favourite build thread, nearly there....

 

[Vulgalour]

Tomorrow... I'm hoping to have it running tomorrow. I know I've been saying that for a few days now but hopefully tomorrow is the day.

 

[Vulgalour]

Right chaps, important update.





It ran.





Then it didn't. The problem is the carburettor. I've got fuel, spark, compression and combustion and the car will run but only if you put fuel directly in the carb, bypassing the important twiddly bits of the carb. I do have a rebuilt kit coming in the post so I can get the carburettor sorted out properly. Until then, I'm bolting stuff back on because, fundamentally, it is all working now.



Apart from the fuel gauge.

 

[Vulgalour]

Report in full then on this.

I knew it couldn't be much stopping the car running so before Mike got back from the unit with extra tools, I hooked up a jerry can of fuel by the front wheel below the pump to see if the pump could pump fuel and it can, very well. I double checked for spark at the sparks which I'm getting and I already knew I was getting decent compression. All the ingredients were in place so it should run.

After a few attempts to start fuel had got all the way up to the carb but it clearly wasn't getting further. When Mike returned, we blew the main fuel line through that runs the length of the sill and it spat a few bits of sandy stuff out and then just fuel vapour so that's probably clear now. I'd also got the top off the carb and found the float was free moving and still being a float and there was very little by way of sediment in the float chamber. The fuel passages I could get to without fully dismantling the carb off the car were a bit gummed up and I cleaned out what I could so fuel flow into the float chamber was now very good, but fuel flow out of it wasn't happening at all. That, we decided, was the cause of the problem.

So, we put some accelerant down the intake and attempt to start the car, which happened surprisingly willingly. However, it's virtually impossible to run a car like that so we very soon didn't have a running car again. It was, however, a moment of great joy to know that it does work and should work very well once the carb is completely cleaned up and rebuilt properly.

That means my next job is to refit the front sheet metal, put the steering rack on and connect anything that still needs connecting so the car is ready to go once the rebuild kit arrives. It's a really good place to feel like I'm at after a very long and frustrating slog.

 

[Vulgalour]

Let's have some more good news.



Tyres - Full set of five, brand new, arriving from the UK.

Radiator - the German company I ordered from have found an alternative supplier when the one they had listed wasn't in stock and a new one is being delivered.

Rear screen demister switch - also in the post, coming from Spain

Carburettor rebuild kit - also in the post, coming from Croatia

New choke stop/arm - mine is pretty mangled, doesn't really work. One in the post from the Netherlands (thank you, harbourseal!).



Everything is due to be here between the 8th and the 20th



The only thing I haven't decided on yet is the best solution for the in-tank filter. The next few days are predicted to be quite mild, for the time of year, so I should be able to crack on with quite a bit now.

 

[harbourseal]

The fuel filter is available from der Fransoze.
https://www.franzose.de/en/Renault/R4/Kraftstoffanlage-Zeboehoer/ANR14134/

But maybe you'll be able to find something locally.

 

[Vulgalour]

Oh! That's actually really useful. They have a sender listed for the 2CV that's the same as the one in my car and it's not much more than the filter on its own so I'm going to order one of those. I do find Der Franzose difficult to navigate sometimes and hadn't been able to find the sender at all. Thank you for the tip off.

---

Since I'm waiting on parts and had lots to do I didn't fancy tackling that fuel tank today. Instead, I just cracked on and got a lot sorted out. It rained last night so I was delighted to discover my headlining wasn't wet at all at the windscreen edge.

Then I just went through and bolt all the bits and pieces back together. The engine bay is a terrible looking thing, it's a right mess as standard and there's not really any way to tidy it up. Everything is back in place, even the radiator, so that I have my garage back.

That took less time than expected, especially with it being such a mild day today, so I got on and started fitting the exhaust. You don't even need to jack up the car or take off a wheel to do this which is incredibly satisfying. Front silencer in.

I haven't got the exhaust paste at home so the main pipe isn't connected yet. Popped the clamp on just so it's all in place ready to go later this week.

There's one hanger under the passenger door.

Another under the boot.

To hold up the back box, there's one hanger under the rear end. I couldn't get this to come undone as I don't have a socket or spanner large enough or anything strong enough to grip the rubber part while I undo the nut from the captive bolt.

Rear mud guards went back in. These did such a good job of keeping all the mud out of the upper reaches of the rear bodywork I thought it would be daft not to reinstall them. They're a previous owner made thing I think and just push into place and hold with friction for the most part.

I'd already refitted the face and bonnet so there wasn't much else to do. Decided to clean out all the dust and bits of rust flakes and stuff from the car being full of old parts and the like. I also removed the boot liners so they wouldn't trap what little water is coming in through the side windows and aren't at risk of being damaged. I leave the parcel shelf dropped because I don't want any more water getting on it through the rear screen which I really need to remove and reseal.

There was a lot less water coming in through the doors than usual after last night's rain so I think the seals are sort of filling out the spaces they need to now. Still not perfect, but much better. Mopped out what little water there was and all the rest of the scaff before putting the back seat up again.

In the front I tidied up and vacuumed out the talcum powder now its done its job. I am missing the return spring for the throttle pedal but I can get a new throttle cable with the spring and other fittings from Italy which might be a good idea given the condition of my current cable.

There's hardly anything left to go back on. Some side trim, the mud flaps, the front undertray and the back box. Other than that, there's a few jubilee clips to refresh and the parts I've ordered to arrive.

So yeah. Nearly there now. Just niggles to work through and parts to arrive. The front suspension has even settled nicely now the engine has been in the car for a bit.

 

[harbourseal]

Why buy a Citroën sender if you can buy the complete real thing.
https://www.franzose.de/en/Renault/R4/Kraftstoffanlage-Zeboehoer/ANR82934/
Nice work. Going for the home stretch.