Independent Renault Forums banner

Issues after converting from Dual to Single Mass Flywheel

51K views 381 replies 21 participants last post by  Deebz 
#1 ·
Hello Folks,
Ref: 2003 Laguna 2.2dci 'Privilege' Sport Tourer
After an extensive year long refit, with many 'upgrades' I arrive at starting the engine.
Most relevant changes are: Timing belt and clutch system. With regards to the latter, I had opted to convert from Dual Mass Flywheel to a Single Mass unit.
On starting, there was the understandable reluctance for the engine to start, mostly fuel bleeding issues. After an afternoon of turning over the engine, the battery (upgraded to an 85Ah/ 800cca Yuasa) run out of oomph. But just before it died altogether, there was one solitary 'cough'. Second afternoon, battery now fully recharged and continued the starting, which on around the fifth attempt resulted in the engine firing up. It spluttered into life and ran for 10 seconds, then stopped dead. The onboard synth voice informed me there was a 'Fuel Injection issue' - consult your Renault dealer. I ignored this and continued, the engine started to warm up and run smooth, but only for 10 seconds with the same warning (until I turned her off...). The engine would not tick over, but did rev out to around 2000 rpm, then died as before. This on each repeated attempt.

Now in reading various comments on one of our forums, someone had experienced a similar issue, which he resolved by changing what he called the TDC sensor at the rear end of the bell housing. Haynes call this item the TDC/Crank Speed sensor. I disconnected this device to see what happened. The engine would not start at all. On re-connection, the same thing happened, it would run for 10 seconds and stop.

Now there are two main sensors on this engine for determining the timing. One is on the fuel pump, the other being the aforementioned crank case sensor (...which I am doubting is a TDC sensor). However, if it is a TDC sensor, then how can it sense the TDC, when the flywheel is different? Let alone allow the engine to run at all....

Remember, the engine runs, more or less as sweet as a nut, but only for 10 seconds. During the refit, the ECU was removed, all electrical connections connected to the engine systems were cleaned and refitted.

Other 'upgrades' included the fitting of an improved Concentric Slave Cylinder, along with new 'aeroquip' hosing and Lockheed master cylinder. Alternator was replaced with a 180 amp unit. New stainless inserts/liners in the vertical intake ports (to resolve the oil leaking issues within the rocker cover), new Gates timing kit and gaskets. Full intake and EGR clean and the fitting of a coolant coil to the EGR cross pipe.

I suspect an ECU code fault. Although the onboard display does not verify this, during those ten seconds the display depicts a 'bar graphic' that counts up to around five or six bars and the words 'Test of Control System' are displayed. But the worrying aspect is this TDC sensor. Because obviously with a completely different flywheel, if this is the problem, then for me it is back to the drawing board. Though I cannot understand why the engine starts and runs, if this was the case.

Any 'professional' insights or advice would be extremely welcome at this juncture, as I really need to get this vehicle back on the road pronto. Thanks in advance,

Deebz
 
See less See more
#3 · (Edited)
Thank you ours2012, for a response, but really I need some serious input here :| with advice from anyone who has done a DMF to SMF conversion. :forehead: As I've said in my somewhat lengthy post the engine actually starts and runs, quite well, but ONLY for 10 seconds, then the ECU shuts it down. One would only use 'easy start' on an engine that did not want to start at all. This is an ECU fault code issue, well that is what I can only surmise thus far. Cheers.

PS: I may only be a 'junior member' on here, but I am neither 'junior' in age or experience. Thus far I have maintained every vehicle I have owned from bikes of pretty much all makes, cars/vans - Fords, Vauxhalls, Renaults, numerous marine engines (...I am even Mercury inboard/outboard trained) to stairlifts of all makes, I am also an electronic technician (Radio comms and electro-technical). However, modern car systems, especially common rail/ECU governed engines is an area of expertise that I am still grasping.... Obviously. :|
 
#5 ·
Thank you ours2012, for a response, but really I need some serious input here with advice from anyone who has done a DMF to SMF conversion. :forehead: As I've said in my somewhat lengthy post the engine actually starts and runs, quite well, but ONLY for 10 seconds, then the ECU shuts it down. One would only use 'easy start' on an engine that did not want to start at all. This is an ECU fault code issue, well that is what I can only surmise thus far. Cheers.
In fairness this man (ours2012) is so serious that only 3 people in the world have seen him crack a smile and he's married to one of the 3! In fact he is an expert and any questions he might ask are for a reason.
 
#4 ·
Ideally you would need to live data during start and the ECU shutting down the engine. As you say it would be doubtful there is a crankshaft position sensor (CPS) or flywheel fault otherwise the engine wouldn't even start. Two scenarios where the ECU will shut the engine downr are if the ECU senses too high a fuel pressure in the fuel rail or there is inconsistencies between the CPS and the camsaft position sensor/s. A poor electrical connection can cause similar faults. Without liove data my comments are only an educated guess.
 
#7 ·
Thank you madnoel10 for your erudite advice. Yes I agree entirely. As it happens, since I first posted, a friend up the road with a Nissan van (1900 version of my engine...) has a Renault fault code reader. He is expected over later today, or maybe earlier in the week. We will then be able to obtain 'live data' on this issue, which obviously and hopefully will be a leap forward in my understanding. The engine runs well, one gets the impression it would love to carry on running and tick over... But its brain has other ideas.... The onboard display, seems to be 'counting up' though its check list, it reaches about five 'bars' and then shuts down the engine. This it does on every start, which now is getting on for fifty.

Regarding the fuel rail, it was removed to facilitate the cam belt renewal. I cleaned it and the associated injector pipes and cleaned, carefully the injector pintles. All electrical connections were cleaned with isopropyl switch cleaner, including the CPS and Cam sensors.

I surmise that the CPS, situated to the rear and beneath the engine in such a way as to 'read' the flywheel teeth, is a 'hall effect' device. I assume the cam sensor is of similar design. But other than cleaning, neither of these devices have been damaged or disturbed and when the engine was last run (around three years ago!!) they operated at nominal efficiency. However, the Single Mass Flywheel is obviously different, though the starter ring is the same and it was purchased specifically as a replacement kit for this engine. Others who have done this conversion report no issues such as mine.

I will keep you posted and again thanks for the 'educated guess', the more of which are always appreciated.
 
#8 ·
All due respect to your lengthy post.

What we have is a motor that has been stripped down, timing, clutch, electrics all disturbed.
Focussing on one aspect such as DMF change to single may be the correct answer but....

If the TDC is not reading, it will not start.
As it is, assumption would be that it is operating properly.
The caveat on this is that the relevant positions between trigger and sensor have not changed.
Not being au fait with changing a DMF to an SMF, I'm not qualified to answer that.
 
#9 ·
Hello ours2012, there is no problem with the engine starting... It is being shut down by the ECU after 10 seconds or so of steady running. I fail to see how easy start would resolve anything here. However, I will concede that the fuel itself has been sitting in the tank for nigh-on three years... But I did 'prime' the filter chamber, when replacing said filter, with clean diesel. Are you then suggesting that the fuel may be stale?
If so, then how does the ECU recognise this?
 
#12 ·
........ Are you then suggesting that the fuel may be stale?
If so, then how does the ECU recognise this?
Of greater concern then stale diesel (which will still fire) would be that it isn't getting to where it should.
Fire up, splutter and stop is a classic symptom with old carburettor engines of the float valve sticking.
Obviously won't be that in this case but could be indicative of an issue with fuel.
ECU would recognised by fuel rail sensor reading dropping BTW.

I'm intrigued by your description of the ECU test display cycling..... simply dunno what that is about but would like to discount it if nothing else.

If it will run on easy start, aspects like timing can often be removed from the questionable item list.
 
#10 · (Edited)
I have done a few DMF to SMF conversions (VW, Skoda etc) and they always started so I don't think that's what's causing the problem. If the flywheels are the same size and it is if the starter is engaging and as they usually only fit one way so the timing shouldn't be off. If the ECU was kept dry it should be ok? Rubber does perish if unused for a long time I'd start with the fuel system
 
#11 ·
Absolutely dancingDad.... If there was a problem with the crank position/speed/TDC sensor, then I would also surmise that the engine would not run. BTW, the engine was not completely stripped down... I only removed the rocker cover in order to replace the cam belt. And the gearbox was obviously removed to facilitate the clutch/flywheel change.

I agree, who we need here, is input from someone who has done a DMF to SMF conversion. Again, on reading threads in that category, no one who has done these conversion flags up any issues such as this, which leads me to think that this issue is more to do with the ECU/Injection system anyway. I do not think that the item often referred to as a TDC sensor is in fact a TDC sensor. If that were the case, then how does the ECU see TDC? Given that the flywheel is different. Baring in mind that the engine runs, albeit for 10 seconds...
 
#13 ·
Lets start again, you have no idea what it is, I have no idea also,.
But you are on the assumption it is the reference point of the flywheel, to TDC.
We are trying to explain to you, is it fuel related, or electrical.
With easy start, you will have the engine running more than ten seconds.

Are your reversing lights working, again another daft question, as you read it.
But are the two plugs on correct, the TDC multiplug is not on the reverse, or vice versa .
(Yes and it has happened on here, engine out a long time, and two plugs mixed up).
10 seconds is no indication at all, but it can fubar the injector pump, as diesel is a lubricant, for the pump.
So use some easystart, this then in turn will allow the injector pump to build up enough pressure.
This in turn will force all the injectors to open,
Not spit a small amount of fuel in
 
#14 ·
The only issue I ever had after conversions was that the pedal felt slightly different after it. This was down to the SMF being thinner and the release bearing having to travel a little further to press the plate. It's something you'd get used to within a mile of driving
 
  • Like
Reactions: Deebz
#15 ·
I suspect an Incoherence between Crank & Cam sensors. IMHO, About the only way the ECU would know to call for a shutdown. If that's whats happening.
How Are you reading an "engine kill" signal?
 
  • Like
Reactions: RenBen1
#16 ·
Indeed DancingDad, I would agree from experience with more conventional diesels and petrol engines that stale diesel would still burn, albeit erratically... But we have no spluttering or misfiring or lumpyness ... The engine does run, as smooth as can be determined given the short duration and temp, but only for 10 seconds or thereabouts... Then the ECU cuts it out. This is not the typical fuel starvation stop. This is a complete shut down by the ECU.

The Renault Laguna 'Privilege' is fitted with a liquid crystal 'heads up' display. This shows a check list and other relevant info. It does a quick check, showing the heaters are enabled then not, oil level OK, then it says 'Start'.
On starting, the display then shows this 'bargraph' (similar to a VU display on a tape recorder...) which counts up to around five or six bars (about half way) a notice saying 'Control System Test' is also displayed beneath the 'bargraph', then a gong 'dings' and a polite female synth voice informs us that there is an 'Injection Fault, consult your Renault dealer'.... At that point the ECU shuts down the engine.
 
#17 ·
Okay, ours2012, I understand what you are saying, although the reversing light connection is on the gearbox, which cannot possibly be reversed with anything locally. The same goes for all other connections, with perhaps the exception of the vacuum valves associated with the damper diaphragms, situated as they are, on a bracket or on the front of the engine head. Although the loom has not been extensively changed, just re-lapped here and there, so all connections are where they should be and having 'keyways' are unable to be connected wrongly. I am confident that all connections are correctly fitted.

Regarding the easystart, thank you for explaining your reasoning here... And I understand your point now. I must confess that I've never used easystart on any fuel injection engine (plenty of times on bikes, normally aspirated engines, like petrol cars and outboards...), even the odd standard diesel, but never on a common rail engine. I have not purchased any easystart for ages, so Monday I will do just that.

My apologies for not getting your drift earlier... Yes it did seem like a 'trite' answer to me, but I stand corrected.
 
#18 ·
Well, as it happens, not only did I do the DMF/SMF conversion, but also completely replaced the concentric slave cylinder with a Hyundai item (having tried various types in the process of elimination and getting the 'throw' right). The main reason and length of this refit. The OEM item was, simply HORRIBLE. A nasty piece of plastic, with those horrible push-fit connectors. ON A HYDRAULIC LINE! My new system took some designing and a fair amount of boring and filing, but I managed to locate the Hyundai CSC into the Renault gearbox nose... (...I did have to get it bored out slightly mind). So for me, there is no issue with the pedal having further to travel as the new item fills the spot. I also doubled-up the seals inside the CSC. Which unlike the original, has an input and bleed union port. The horrible AN4 steel hydraulic line has been shortened and replaced with an AN4 aeroquip hose (stainless braided), also I've replaced the equally horrible master cylinder with a standard iron (Land Rover)Lockheed item (larger bore of 21mm) and incorporated an hydraulic 'accumulator' or pedal adjustment valve on the bleed line. This item, sourced via JEGS in the USA is made by RAM, who are renowned clutch racing specialist. It allows me to place the 'biting point' of the clutch, right where it is comfortable. All fittings are to 'aerospace standard'.

The clutch feels tight and responsive, albeit a tad heavier than the original item. The anti-vibration damper has also been omitted from the upgrade.
 
#23 ·
If you look at any modern flywheel, you will see that there are a series of teeth, pegs, castellations or similar around the outer edge as well as the starter ring teeth.

Unless I am mistaken, there will also be a gap or possibly an extra wide tooth at one point.
The teeth are read and give an RPM to the ECU, the gap/wide tooth provides a blip..... TDC.

I've never tried it but would suspect that the ECU is allowing start based on the RPM and pre-sets.
But then cannot reconcile TDC and is shutting down.

Pure guess but until someone can explain why the flywheel does not need timing, I'm sticking with it.

Take a look at the teeth on the old DRM.
Is there a gap or wide tooth ?
 
#22 ·
Although my knowledge regarding this vehicle is limited, that goes for any common rail diesels, I cannot see how this can be an issue of the reference point of the flywheel to TDC. I am more inclined to agree with ours2012 that this issue is either electrical, but most likely fuel (Injection system) related. Not forgetting that the damn ECU 'robot' even informs me there is a 'Fuel Injection Fault'. I am more than happy to be corrected here, but surely the engine would not run at all, if the position of the flywheel relative to TDC was out... Thus I conclude that it is irrelevant where the flywheel is placed with respect to TDC, which also leads me to believe that the sensor that reads the flywheel teeth is not a TDC sensor at all... But that obviously it does have relevance to the rotation of the crank/flywheel, for when I disconnected said sensor, the engine would definitely NOT run whatsoever.

I would therefore also conclude that the ECU registers TDC via the cam position sensor (located on the fuel pump). The fuel pump has never been disturbed and throughout the refit, was locked in place by the crank-setting pin. Remember, on these models, the HP fuel pump is driven by direct gear from the crank, so cannot be disturbed if the crank is locked to TDC.

I wish to say at this point, that I really DO appreciate the time that you guys have given to mulling over this problem. I think we are all in a bit of a vacuum on this at present, what I need is to interrogate the ECU and establish a more defined fault code. But I am honestly grateful to all of you for your inputs thus far.
 
#26 ·
On inspection of the DMF (OEM), there are no gaps in the starter ring teeth, all are equal, if not, the starter would jump or lock when it located the difference is teeth size, or a gap. To the rear of this item, there is a series of square holes around the circumference, which are castings in the inner flywheel, all are of equal size. Further in by radius there was one long (around 40-50 mm) 'slot' cast into the rear section of the DMF. As for the replacement SMF, the flywheel is completely uniform across the rear part (no corresponding slot) and the teeth are as per the staring ring of the original. The SMF is completely symmetrical, with three rectangular gaps or 'castellations' at 120 degrees from each other, but these are, as you can see, on the front of the flywheel.

I have include this photo, for what its worth, of the replacement SMF, but unfortunately I do not have one of the rear of this item.
 

Attachments

#27 ·
Please post a picture of your old flywheel.
The castellations should be clutch side of the starter ring. Like the one I posted earlier.
 
#28 ·
I cannot see your picture Nottnoc.... Don't forget I'm new to this forum, I'm not sure how to 'see' pics.
I cannot post a pic of the old flywheel, not until tomorrow anyway and it is all rusty, given that it has been sitting outside for almost a year... And how can this TDC mark be on the clutch side of the flywheel? The sensor in question is on the rear of the flywheel.
 
#29 ·
Go have a look at post number 24. I'll Go google some images, See if I can find your specific one.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top