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280se - new to me, warm stalling!

Started by SteveDuNord, 04 May 2022, 10:57 AM

SteveDuNord

Quote from: revilla on 01 July 2022, 01:28 PMAnd with that wash, the frustrations that invade us all sometimes wash away too, at least temporarily... :)
A side effect of that joy is ignoring the "little" defects (eg rust spots, etc) that they might have. To wrap up the successful episode, a nice ride of a few kilometers is highly recommended by the doctors... :)

Ha, indeed. Took it out for a long drive today. Went to a little Bay I'd been hoping to take my new car to, prior to disabling it.  ;D



(not my dog)



Car performed faultlessly. Treated it to the highest octane fuel available locally, 97 RON.
Only issue was the sunroof failing to close when the storm clouds were looming, almost chopped off a finger lifting the offending flap.

Once the rain started, and boy did it start, I noticed the fast setting on the wipers doesn't work - could barely see!

Otherwise, delighted. Love the little sewing machine engine. And it's much more nimble than I expected.  8)
'77 280se

SteveDuNord

Well having struggled to change the transmission fluid without jacking up the car (quick piece of advice - don't do this), I am now ready to set about with the fuel pressure testing.

Here's the rub: what kind of fittings do I need for my m110 engine?

This kit has the little round fittings, I think they're for banjo bolts as found on the WUR?
https://www.ebay.co.uk/itm/183950579736


Whereas this kit has normal looking bolts:

https://kurth-classics-autoparts.de/gb/warm-up-regulator-wur/227-k-jetronic-pressure-testing-gauge.html


Both Kjet specific. Anyone know which one I need?
'77 280se

rumb

A variety of fittings can be found here:

https://belmetric.com/fittings-plugs/banjo-fittings/
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

Jan S

I have the pressure tester in the first pic. Works great and fits k-jet.
1975-mod W116 450 SE with 6.9 engine

SteveDuNord

#64
Thanks chaps, have ordered the kit.
In the meantime, I decided to do a valve clearance adjustment.

The cover is dirty, especially down in the spark plug wells - black! And the nuts are rusty. So ugly.





The underside is awful, but caked on and probably not a problem.



Cam lobes look good (?) and the chain is nice and tight.



27mm socket to turn the lobes in the right direction.



A 17mm spanner worked ok but would sometimes act like the nut is rounded off. Enter this socket, which worked a treat. These valve nuts are tough to turn!



Lots and lots of scrubbing, sanding, dish soap, wd40 - whatever I had to hand. The nuts were horrible, but I managed to get a nice patina look going. Took a while....











Intake adjusted to 0.10, outtake to 0.25. And a nice new replacement gasket.
Nuts tightened to 5 nm as advised recently on this very forum.

Drives great now. The accelerator pedal actually works.  ;D





'77 280se

rumb

'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

johnnyw116

JohnnyW116

SteveDuNord

Since fiddling with the mixture screw, which had fixed the warm stalling in gear issue, I've been experiencing a hesitation to turn over from cold.

Today the hot restart stall issue resurfaced, and having the steering wheel on full lock instigated the process - which implies a vacuum issue, but I have no leaks.

I'm musing on the fact that the mixture can be adjusted to achieve best vacuum.

Maybe the mixture needs readjusting.

I dunno! Will experiment tomorrow.

'77 280se

rumb

There are 2 paths of hesitation (taking a while to fire up?) cold starting.
1. your injectors leak and the engine is too rich when you try and start it.
2. your cold start injector isnt working.

" I've been experiencing a hesitation to turn over from cold"
Please describe what that means.


timing will affect the vacuum, I dont think the mixture will.
An old school method of setting the timing to to set it where the vacuum is highest at idle and then reference that with a timing light.

hot restart is sometimes a bad fuel accumulator. - the pressure leaks out and then it takes longer to get gas back to the engine.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

SteveDuNord

I mean that it won't fire over first time. Complicating the matter is the fact that there is an issue with the gear selector (probably bushes). So recently it would start only in N, but if you cycle through the gears it would start in P.

It's all connected!  :o

I've found that you can indeed affect the vacuum with the mixture screw, for whatever that's worth.


I haven't touched the timing yet. Need a timing light.

The accumulator was last changed in 2015 according to service records, along with fuel pump and filter. It would certainly tie in with the fuelling issues. (Maybe would explain the low return volume?).

2019 it had the tank cleaned out.

When the fuel pressure kit arrives things will really kick on. I'm trying to avoid more parts swapping. ;D 

'77 280se

johnnyw116

I had in the past an bad fuel accumulator on my 280Se the cold start was ok , but when i parked the car with an hot engine and after about 30/60 minutes i wanted to restart the car again i had to crank it for 30 seconds to get the engine running again , it started similar like starting an flooded engine , in my case after replacing the fuel accumulator it solved the hot start issue
JohnnyW116

SteveDuNord

Quote from: johnnyw116 on 16 July 2022, 05:53 AMI had in the past an bad fuel accumulator on my 280Se the cold start was ok , but when i parked the car with an hot engine and after about 30/60 minutes i wanted to restart the car again i had to crank it for 30 seconds to get the engine running again , it started similar like starting an flooded engine , in my case after replacing the fuel accumulator it solved the hot start issue

My issue is different in that it will restart when warm, but revs drop when you put it in gear, applying accelerator causes a stall, and turning the wheel makes it worse - presumably because it affects vacuum.

Could be WUR. Accumulator. Who knows?
'77 280se

rumb

I would start with checking the the fuel accumulator, though I am not sure exactly how, someone may know.

2nd I would check the timing, as that is an essential part of having engine run properly.  Remember  that the vac valve for auto tran needs to be disconnected, though again someone can verify that.

Once those 2 items are ruled out then a fuel pressure check, and finally the FD is then suspect and may need rebuilt.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

Jan S

When kit arrives check:

- system pressure
- drop in system pressure, i.e. drop in system pressure when engine is stopped ... system pressure after 2 min ... 4 min .... 6 min .... 8 min .... 10 min .... 12 min up to 20 min or longer (that will tell you if the accumulator is ok or not)
- control pressure cold and during warm up for about 15 min

Those three things will tell "a whole story"
1975-mod W116 450 SE with 6.9 engine

SteveDuNord

Cheers! Kit arrived today so I'll wait for the heatwave to pass and get testing in a couple of days.
'77 280se