1987 w124 300 TE starts, runs for seconds only

[300_te]

Hello there,

I'm a new member asking a question on behalf on my dad, who's got a 1987 'D' w124 300 TE.

Today the car would start as normal, but only run for a few seconds before cutting out - enough to get it half the way down the road, where it now resides.

The rev counter would stick and perform rather strangely, but there didn't seem to show any other odd symptoms.

The car has idled more lumpy lately apparently but not cut out previously, but now it just dies after about 10 seconds.

If anyone's got any ideas of what to check / do / look for we'd be incredibly grateful as the thing's stuck down the road- apparently the ABS light hasn't been on so does that rule out OVP stuff? (I once had a w126 that had OVP issues).

Thanks in advance for any assistance!

 

[300CE]

Hi 300te, do you know when it was last serviced as I'd start by checking & cleaning the plugs & the dizzy cap first (give it a wipe inside). I'm afraid that's about as far as my technical ability goes & I'm sure one of the helpful chaps will be along to give more advice. Good luck & give an update once you resolved it!

 

[300_te]

Hi 300CE - thanks for the response - think it was serviced recently! but will check dizzy and plugs...I have a feeling it's something electrical, but could be wrong!

 

[GP801]

OVP relay is involved in al sorts of things but do check the distributor cap. We had one go on a 300e-24. Had a minute crack in it. I was told it was quite a common issue

 

[Ian B Walker]

The clue is in the rev counter as GP's post. OVP relay.

 

[300_te]

Ahh, thanks for all the posts! Very helpful indeed.

I'll check the OVP relay - is it near the battery on these? Is it likely to be a case of just popping a new one in and away we go?

Thanks again.

 

[Ian B Walker]

Check the 10amp fuse in the top of it first. If it has not blown see if you could borrow one from a friend etc. and see if it solves the problem. If it does you have two options. One is to take it to pieces and examine the soldered joints and two, purchase a new one. It is situated next to the ECU behind the battery. Sometimes covered with a black plastic sleeve.

 

[300_te]

Brilliant! Thanks very much! Replaced the 10 amp fuse and it seems now to run as it should! Really appreciate the great advice - and speed of it!

Is the OVP relay a common thing? That's twice i've encountered them doing odd things in Mercs! Great cars though - and a lovely sweet in-line six!...

 

[GP801]

They are a common source of trouble. Caused fuel pump not to function on ours. A new one for ours was £80 from MB so worth it if its starting to give trouble