Starting Issue, 1974 280 SE

Hi Carl,

soory it might be that I ask the question again: Did you do the spray and leakage test on your injectors and cold start valve? I they were leaking, they would fill a cylinder with fuel and that would not be able to start then.

Hi Volker,

It's certainly a mystery! Yes, I have checked the spray pattern of the injectors and that of the cold start valve. They do not leak.

I have to admit, after the recent tests, I have no option but to start pulling things off and replacing them. I think I will start with the fuel pump. I have some other commitments with vehicles that I must attend to so I will put the W116 at the back of the factory and perhaps revisit it during our winter. I cannot express how frustrating the exercise has been. I really dislike the car very much because of its behavior and I admit I have lost motivation to work on it at present. Thanks to you and the forum for all your help and suggestions. It is very much appreciated.

Regards,

Carl.

Hi Carl,
I must admit I did not see the video before... have been quite ill the day you posted it.
We have a game called 'Bosseln' here in Lower Saxony, and it is very tiring to practice this sport intensively.

One last question before the winter takes the car to the end of your factory:

Did you measure the voltage at the ignition and the injection system when starting?
Take care to measure at the same point / directly at the component, taking the ground from the same point the unit does.

Maybe the whole problem isn't related to the D-Jetronic at all, the ignition switch is faulty or the mains coming from the starter are badly connecting, a ground-wire doesn't give contact...

D-Jet-cars are starting immediately within a maximum of 2 seconds. Your car isn't a D-Jet-car

Regards
Norbert

.

Hello again,
I just remembered a small car (Renault R4), which accompanied me through my whole study.

It started always very bad whe cold, and I did not get it under control. Much like your car.
The engine got so hot that I had to drive in midsummer with heating. I had to refill coolant from time to time - but not daily or so..
Nevertheless I made a CO² - leak test without results. The car drove - so I left it as it was.
So I drove this little car more than 200,000 km, until it was completely destroyed overnight in the parking lot by an accident fugitive.

I disassembled the engine and found several cracks in the cylinder head.

If cooling water runs through cracks in the combustion chambers, the following happens:
- The very cold engine starts badly because the combustion chambers and the spark plugs are wet
- The hot engine starts well because the seeping water evaporates quickly.
- The further cooled down engine starts again bad because the infiltrating water does not evaporate.

Regards
Norbert

Hi Norbert,

Last week I started the 280 SE, the first time in 4 months. I had not driven it during this time because I put it up the back of the factory trying to forget how annoying this car has been! In the meantime I drove a car with L-Jetronic and K-Jetronic instead and life was good! No issues with those two.

Warmer weather is now on the way and I now have a little time to get back into this D-Jetronic project.

I firstly made sure the battery was fully charged. Of course I expected the engine to take 15 separate cranks to start, but this time I was astounded that it started first time! Although the idle was initially very rough, it eventually ran nicely on all 6 cylinders and drove fine.

My joy was short lived since its initial start after storage, since then, the car has gone back to its usual difficult starting, this morning taking 17 separate cranks of the key to fire.

The voltages at the ignition system and injection system are correct.

I read with interest about the R4. In fact, this possibility has also crossed my mind, I really hope the head is not cracked or has a failed head gasket. It's a really big job to remove the heads on these M110 engines. However the car is not consuming water.

I will consider my options over the next few days and advise. Thanks again for the replies Norbert.

Regards,

Carl.

Dear All,

After much effort it appears that I may have successfully fixed the starting issue on the M110 engine at last...... its been performing faultlessly since last Thursday. Let's hope it stays that way....

I cannot say for sure as to exactly what I did however! There were some items I attended to whilst I had components removed (Such as the camshaft cover and ignition distributor) and I'd lost patience with this car to the point where I was not going to waste more time on checking it started after each job.

1. Removed the camshaft cover (The valves were due for checking anyway) and checked the camshaft timing, it was correct.

2. Checked the valve clearances. One of the inlet valves had opened up 0.05mm. 4 of the 6 exhaust valves had closed very slightly, by 0.05mm. I corrected these figures of course.

3. Checked the head torque, nuts 1 +2 as per the tightening procedure in the workshop manual required retensioning. 3 of the camshaft assembly bolts required retensioning.

4. Replaced the spark plugs.

5. Removed the ignition distributor, cap and leads, checked and cleaned the leads and plug ends. Lubricated the distributor advance mechanism and checked operation, it was correct.

6. Cleaned the rotor, leads and cap (Polished the brass contacts). As these were 15,000kms old, replacement was deemed unnecessary.

7. Replaced the ignition points and set the dwell. Lubricated the cam.

8. Checked the dwell of the D-Jetronic points. I noticed that whilst the resistance was very low, the dwell of the points per side was asymmetric by 20 degrees. I could move the points enough in the housing to correct this figure (So the dwell was the same per side). Lubricated the cam.

9. Removed the air cleaner and housing. Blew out the air cleaner with compressed air. It was 15,000 kms old so replacement was deemed unnecessary.

10. Cleaned the throttle butterfly and housing, checked for any binding, adjusted throttle linkage and lubricated.

11. Removed wiring in the engine bay, cleaned connections, tested for continuity with D-Jetronic harness.

12. Removed D-Jetronic ECU, checked harness connections, cleaned board (Where the harness mates)

13. Checked engine bay sensors, all OK.

14. The earth connection from the battery to the chassis was not as tight as it should be. I removed the earth strap, cleaned the area and fitted two new "Star" washers to grip the metal.

15. Upon checking the alternator, one diode appears faulty although by 1,600 rpm the charging rate seems fine. I will attend to the alternator in the coming weeks.

16. Fitted the new battery I bought for it last year.


And so that was that! Would anyone like to have a guess at what the problem was? Perhaps it was a combination of a few items, I don't know.

I would like to thank you all for your help and encouragement, I was really over the car in the early part of the year I was ready to set it on fire!

Regards,

Carl.


Here's a little video of the first start after assembly:

vid115.photobucket.com/albums/n281/carl3...0896_zpsmsy4sko7.mp4


Some images of the work:

s115.photobucket.com/user/carl308888/med...jpg.html?sort=3&o=38

s115.photobucket.com/user/carl308888/med...jpg.html?sort=3&o=37


And.....finally back together:

s115.photobucket.com/user/carl308888/med...jpg.html?sort=3&o=11