me again.

[david55amg]

Hi all. Sorry to trouble you all again but I have a mercedes 300e 1989 vintage as well. My missus has been nagging me to get rid of it so I thought i'd take it out for a run. I charged the battery...k***ked!! Went to get a battery then fitted it. WOW Started on half a turn!! what a machine!! Got trade plates and took it for a spin. everything working perfectly, put my foot down and, my god, it dont arf go!!!

HOWEVER, My elation was short lived. after about 3 miles, just as the engine has got fully warm, the engine developed a misfire then-----------------------------NOTHING!!!!! It just conked out. any ideas because it was running fine till then. Thanking you in advance
p.s. smilies in-op :-(

 

[Dieselman]

Instant failure is usually spark related as fuel coughs before dying.

Open the bonnet at night and turn it over and look for any sparks flying around, check the distributor cap and rotor arm and check for an actual spark at an HT cap.

 

[david55amg]

Instant failure is usually spark related as fuel coughs before dying.

Open the bonnet at night and turn it over and look for any sparks flying around, check the distributor cap and rotor arm and check for an actual spark at an HT cap.

thanks for your speedy reply. Can I just ask, why would it run perfectly while warming up then all of a sudden, in the space of 5 mins , just gradually die!! I was in the industry years ago but it's flummoxed me.

 

[Dieselman]

One thought is condensation in the dizzy. As the engine heats the water evaporates off the head and condenses in the distributor cap.

 

[Ian B Walker]

coils on these are known to be an issue, especially on the more mature car.

 

[grober]

fuel pump or OVP relays??

 

[BlackC55]

Wiring loom? I have done 3 now on the 124's.

They tend to cause missfires suddenly too with out warning. The looms break up as they become old and the plastic covering for the wires become brittle and break off causing shorting etc

 

[kth286]

BlackC55

It is not that generation of car so loom can be ignored.

 

[Dieselman]

BlackC55

It is not that generation of car so loom can be ignored.

Maybe..

 

[david55amg]

fuel pump or OVP relays??

Hi there, the fuel pump is working, I can here it. I just seems wierd that it goes like stink for about 3-4 miles then splutter to a halt. When trying to start, it seems to want to start then just wont catch. When the engine is turning over on the starter, every now and again, it just stops dead, as if hitting a brick wall. I used to get this on my old cars when the ignition timing was over advanced. I tended to think it might be the coil but this symptom wouldn't be ther, or would it??

 

[grober]

Sounds like you might have an intermittant earthing problem somewhere. check your engine to body earth strap and its contacts first.

 

[big daddy merc]

does it make any other sounds just before it dies? like a pinking or an light knocking sounds

 

[Dieselman]

How is the timing set on these engines. If it's by the crank sensor then I think that is the fault, if it's another timing sensor then check that.

When the engine stops turning over can it be turned over if the starter is operated again or with a spanner?

 

[david55amg]

does it make any other sounds just before it dies? like a pinking or an light knocking sounds

No, no noises at all then it just gets rougher till it dies. There's nothing you can do to stop this.

 

[david55amg]

How is the timing set on these engines. If it's by the crank sensor then I think that is the fault, if it's another timing sensor then check that.

It has a black knob on the side of the inner wing with "N" and "S" on it. the distributor is bolted to the end of the head with no adjustment


When the engine stops turning over can it be turned over if the starter is operated again or with a spanner?

No, I think I may be misleading you all!! the starter and relay are working fine and strong. it seems to be the flame front is hitting the piston before the piston is at the top, therefore stopping it dead??
All very strange.....

N.B. Just been to try start it since last friday and it started on half a turn, running well

 

[Ian B Walker]

it seems to be the flame front is hitting the piston before the piston is at the top, therefore stopping it dead??
All very strange.....

N.B. Just been to try start it since last friday and it started on half a turn, running well

Ahhh, so, twin cam engine. Advance mech on inlet cam. it might be sticking in advance. Oil pressure ok? had an oil change recently? Have you tried putting some ATF in the engine oil? "IF" my theory is right

 

[kth286]

Is it a 24 valve ? Probably a 12 Valve that year - 1989.

 

[david55amg]

Is it a 24 valve ? Probably a 12 Valve that year - 1989.

:bannana: have a banana that man!! yes it's a 12 valve, 6cyl monster hewn out of solid granite!! still wont go tho

to answer ian's question, the oil seems ok and pressure is spot on.

 

[grober]

Distributer advance weights sticking? check the advance with rpm with a timing light on the front crank pulley timing marks.

 

[nick mercedes]

Hi all. Sorry to trouble you all again but I have a mercedes 300e 1989 vintage as well. My missus has been nagging me to get rid of it so I thought i'd take it out for a run. I charged the battery...k***ked!! Went to get a battery then fitted it. WOW Started on half a turn!! what a machine!! Got trade plates and took it for a spin. everything working perfectly, put my foot down and, my god, it dont arf go!!!

HOWEVER, My elation was short lived. after about 3 miles, just as the engine has got fully warm, the engine developed a misfire then-----------------------------NOTHING!!!!! It just conked out. any ideas because it was running fine till then. Thanking you in advance
p.s. smilies in-op :-([/

Dizzy cap.