Help required - engine cutting out

More threads by 450SE

450SE

New Member
Messages
187
Points
0
Location
Melbourne, Australia
I've got some sort of issue which appeared Friday night on the 450SE.

For some reason the motor cuts out for a split second while cruising along, giving a surge sensation when cutting back in. At idle (in Drive - say at a set of traffic lights) the miss hits at the wrong time & the engine dies a quick death. It restarts easily enough, but as the motor died on me half way into a major roundabout yesterday :)eek:), I figured it's best to let the car rest!

The miss occurs when the engine is stone cold & also at temperature.
One incidental thing that I noticed the first time it happened is that the rev counter flew into the red zone momentarily when the miss occured although the revs did not increase. (I thought at the time that I was just imagining what I'd seen & the miss was a result of not paying attention to my foot).
I've tried driving with the air conditioner, fan & radio off thinking it could be a problem of lack of power. No difference.
The car has just had a brand new battery fitted.
It is also *slightly* slower to start up initially at the moment (say one extra crank of the engine).
All the leads to the distributor & plugs are firmly in place.

I went to my mechanic Saturday morning who took a quick look at it & short of adjusting the idle speed up a tad, said that I'd need to come back Monday as he was flat out. The idle adjustment didn't fix the problem... It will go into the shop tomorrow with hopefully an easy, minor repair... whatever it is...

Has anybody experienced this before or does anybody have any suggestions as to what it may possibly be? :confused::confused:
 

WGB

New Member
Messages
1,289
Points
0
Location
Perth Western Australia
If it has recently been fitted with a new battery make sure no earth connections have been damaged.

Best of luck - let us know what the mechanic finds.

Bill
 

TJ 450

New Member
Messages
357
Points
0
Location
Perth, WA, Australia
It will be an electrical problem of some sort, most likely relating to the ignition system or simply a bad connection as Bill suggests. The tachometer gets its input directly from the coil, so I would be looking at the wiring or all of the parts in that system before and including the coil for possible faults.

If it was a charging problem, it would flatten the battery and cause more widespread malfunctions.

Good luck.:)

Tim
 
Last edited:

BenzBoy

Grand Master
Messages
7,591
Points
705
Location
Sydney - Centre of Civilisation
The only times I have experienced what you have listed has been a semi-broken and corroded electrical conection which was only successfully diagnosed when it completely failed. I agree it is probably electrical - main feed to the engine or an earth along the way.
Regards,
Benz-Boy
 
OP
450SE

450SE

New Member
Messages
187
Points
0
Location
Melbourne, Australia
Thanks for all of your tips, gents.
My initial thought was fuel due to the surge / quick splutter while cruising or instant - but the rev counter shooting through the red line threw me a bit.
To be honest, I'm not sure when the fuel pump was last replaced but the previous owner is in the process of photocopying all of his old receipts for me.

At the moment I tend to be thinking along the lines of an earth near the battery, perhaps damaged when the battery was replaced.

The car was dropped off to the mechanic this morning. Of course, it didn't miss a beat on the way there or while I was driven back to my office. Typical gremlin...
 
Last edited:

John S

New Member
Messages
636
Points
0
Location
Sydney
Driving up Kurrajong Heights My 450SEL cut out instantly and then started again almost in the same instant. I drove quietly home with no further trouble.

Put it in for a service and the mechanic (Frank Zimmer at the time) said the filter was so blocked he didn’t know how the car managed to run.
 
B

BAR

Guest
I had this some time ago, and incidentally it's how I met the godfather.

Initially I had an occasional miss, then it developed into something that I best describe as having a rev limiter attached... the motor just wouldn't go past 2,200 rpm.

In my case a replacement ignition control module (sourced from and quickly installed by the godfather 'Styria') cured my ills.

My considerations are all centred around electrical rather than fueling issues.

There is also the potential for an intermittent 'shorting' of the ignition leads, when under load, so cold and hot running under load (hillclimb or start off) would be the times when this may be noticed. Try opening the bonnet in your garage at night with the lights off and look for any signs of 'lightning'. Where the charge will short from the lead to engine metalwork.

Its amazing how much erformance can be bettered by fitment of new plug leads and coil leads. Better than a tune up in my case with the 450 and another older Ford.

A faulty spark plug can also cause similar symptoms.

Another possibility is the coil, but your seems to perform most times, so again I'd revert to other gremlins.
 

Styria

The Godfather
Moderator
Messages
9,403
Points
622
Location
Sydney
Hi Tim, I've noticed that all seems to be well - obviously, with the threat of being confronted by the mechanic, the car probably decided to be on its best behaviour. Tell me, what did the mechanic do, and did he find anything at all out of order ?

Now, getting back to your first place query. I have noticed, in the past, that a battery that's down in charge will cause your rev-counter needle to jump up to about 4000rpm momentarily. That's one clue - perhaps your alternator is not charging properly.

Secondly, your green wire from distributor to ignition control module - make sure it is in good condition. If that's faulty, it can easily cause the sort of problem you have/had. Next would be to suspect the control unit itself. Just make sure you have a unit handy as a spare. I invariably include one as part of my tool kit when I take the car for a drive - out in the country.

Other than that, just make sure that your fuel filter is clean and free flowing, and then after that try and determine the condition of your fuel pump, or the relay for the pump as SEL69L has pointed out. Regards Styria
 

WGB

New Member
Messages
1,289
Points
0
Location
Perth Western Australia
Just an idle thought.

Some years ago after doing some welding on my 450 I was driving along when the tacho started jumping all over the dial and the electric aerial started going up and down of it's own accord.

I drove some considerable distance with no driveability issues before I realised I had forgotton to plug the connector to the alternator back in - I had removed it before the welding to protect the electronics.

The flickering tacho needle is probably a low voltage in the system and was the first symptom in my 450.

I'd still look for a connection problem somewhere in the main feeds and earths.

Bill
 

Styria

The Godfather
Moderator
Messages
9,403
Points
622
Location
Sydney
Hi Luke, After yesterday's conversation, I decided to look up the post we had been discussing and, of course, guess what ? Age (old) is starting to leave an imprint on the PC between my ears as I thought I was replying to Tim in WA. Anyway, now that I've got that off my chest, I'll just re-iterate the method of keeping the fuel pump operational at all times - if that's what might be your problem. As I said, just pull off the wiring loom that's connected to the switch near the fuel distributor.

Mind you, having said that, I still think that you have some sort of electrical problem. If you are able to, please keep us posted as to how you get on. Take a close look at that green wire from distributor to ignition module. BTW, hope you enjoyed the BBQ. Thanks to both of you for coming. Regards Styria
 
OP
450SE

450SE

New Member
Messages
187
Points
0
Location
Melbourne, Australia
The car is back in my garage again. :)
The mechanic had it for a week (which didn't bother me in the slightest) & found that the fuel pump was the most likely culprit for the spluttering, surging & stalling.
Originally, my suspicions were focusing on a possible damaged earth lead following a testy battery replacement, followed by a fuel line issue.

The fuel pump was buzzing quite loudly when I was called in last Wednesday afternoon - which I had never heard while sitting in the car, but was quite obvious once standing outside the vehicle.
The fuel filter which I had thought had been replaced in June was also choked full of gunk, which would have exacerbated the problem.

My mechanic drove the car home for a few nights and over the weekend, trying to cause the fault again, but couldn't fault the car.

While the car was in the shop, I also had him attend to a few other minor niggly issues:
* Patch up a minor hole in the exhaust near the rear muffler (1.5mm)
* Replace a faulty brake sensor
* Fit new horns. Hopefully the horse - I mean dog - that ran out in front of me a week or so ago will think twice. As will cab drivers.

He also:
* Refitted the battery properly (battery supplier was seemingly happy to just slam it in the hole & say "there ya go" :mad:)
* Adjusted all fluid levels / tyre pressures / light function & aim etc
* Did an overall condition report

Including $50 of fuel and 3.5 hours labour, the invoice came to just over $700.00, which to my way of thinking is money very well spent! :cool:
 
OP
450SE

450SE

New Member
Messages
187
Points
0
Location
Melbourne, Australia
So back on October 20, I was claiming victory over my engine surge / spluttering / dying issue, citing a replacement fuel pump & fuel filter. Within days, the gremlin had reappeared.
My mechanic was unable to fit the car in for about a week, but wanted to have it for at least a week, possibly two, to properly diagnose the issue.
I got the car back last Friday afternoon.
After driving the car to & from his house for a number of days, the problem eventually reared its head. My mechanic believed it to be (I think he called it)the transistor module - the small metal box behind the front passenger side indicator light.
He sent it off to a specialist to diagnose & repair if required. The box returned a day or so later - unfaultable.
Refitted, the car faulted again that evening. The mechanic sent the box away again. When it returned a few days later, the specialist had diagnosed a fault & rebuilt the box. The car was driven for a few more nights my the mechanic.
When I collected the car, the mechanic told me that he didn't want to give it back to me yet. Asking if he thought the problem was still there, he responded 'No, it's such a lovely car to drive!' :D
 

SELfor50

New Member
Messages
1,197
Points
0
Location
Capitown
That's the control module or something??? Got a bunch of transistors in there?

What was the repair cost if you don't mind me asking??
 
OP
450SE

450SE

New Member
Messages
187
Points
0
Location
Melbourne, Australia
The repair came to around $530, which included $50 fuel, around $350 for the rebuilding of the box & the remainder was labour by the mechanic.
I was quite happy with the bill. I'm even happier that the car hasn't faulted again!
 
Similar threads
Thread starter Title Forum Replies Date
S Help Articles 2
I car died, think alternator, please help. Mechanicals 7
marie_70 Need help for w109 016 300sel/8 6cyl Articles 32
BenzBoy Help needed please. Technical Information 17
s class help with 722.002 trans question re K2 Technical Information 3
T HELP! Which m110 engines are K Jet that fit the 280 SLC Mechanicals 12
L Help - W140 Battery Mercedes W124, W201, W140 and R129 19
J Not 116, but need help cleaning alloy inlet manifold Exteriors and Body Repairs 11
Styria Right back door jammed shut- HELP Exteriors and Body Repairs 22
BenzLover Tech help please. Mechanicals 1
B Replacing Spings with Foam - need help from one of Melbourne's gentlemen Interiors 24
Michel Looking For Help Swapping Radios Mechanicals 10
grant v Please help save the East London Grand Prix Circuit - South Africa Motorsports 1
E REALLY... REALLY Need HELP for W108 280SEL 3.5L Idle Problem Mechanicals 8
E Need HELP on W116, 280S Rear Differential Parts...THX Mercedes W116 5
s class M117 timing chain tensioner help Mechanicals 10
J Wheel required Articles 6
260ebenz W126 part required Mercedes W126 28
chrisp Tools required for basic 6.9 maintenance Mechanicals 15
J 116 Leather Seats required Mercedes W116 4
WGB Assistance required with orientation of front lower arm bushes. Mechanicals 1
WGB Offset woodruff keys - number required Mechanicals 4
Des Caption Required Talking Torque 11
Michel Oil required for 6.9 suspension Mechanicals 88
Oversize 6.9 Engine (Viscous) Fans Mechanicals 2
c107 [JT] The Rover IOE Engine Rover P4, P5 And P6 7
motec 6.9 W116 with M156 engine Mercedes W116 12
c107 Rover P6 3500S engine swap Rover P4, P5 And P6 16
SEL_69L What do yo think is the best Mercedes engine ever? AS the tr Talking Torque 8
Styria Rover P5 IOE engine rebuild Rover P4, P5 And P6 10
S Same Engine Articles 14
Oversize 6.9 Engine Mods by MKB Mercedes W116 5
Styria Bentley V12 Engine Assembly Websites and Links 2
Patrick_R New M139 4 Cylinder Engine Mechanicals 0
6.9forever Engine swap-M102 in W123 230E Mercedes W123 3
Sluggish W116 280s engine options Articles 6
6.9forever M117 - Engine shake at idle Mechanicals 6
Oversize Engine oil type and viscosity Technical Information 6
S New VW Engine Mechanicals 11
T 280 SL (107) slight engine miss Mercedes R/C107 2
Andrew280SEL Engine Ideas for a W114 Mercedes W114 and W115 15
Oversize MB 350 V8 Engine FS Gumtree/eBay/Facebook Listings 0
Oversize 6.3 and engine/trans for sale Gumtree/eBay/Facebook Listings 5
Styria 6.3 engine mounts Gumtree/eBay/Facebook Listings 0
A engine weight Technical Information 1
A engine refurbishment Mercedes W116 3
P Poor starting hot engine Technical Information 9
260ebenz Engine bay photos Exteriors and Body Repairs 17
motec 6.9 Ford wins engine of the year Talking Torque 2
Styria Building an engine Technical Information 6

Similar threads

Top