w124 300te24 running issue

[matt85]

hi my dad has owned a 1991 300te 24v esate for a short while but it hasnt been used much due to a fault occuring, when the car was purchased it ran fine no missing spluttering etc but since has started playing up,

when the car is started from cold it runs perfectly right up untill it reaches around 82/83 degrees then it splutters and cuts out. when you attempt to restart it, it will razzle over then splutter then not start, you can keep doing this and the car refuses to restart.
if you leave the car for a few hours it will restart fine and the same problem occurs.
if you force the car and manage to keep the revs right up once the temp has exceeded around 85 degrees and is up to norm working temp it will drive and run perfectly.

rotor arm, leads.plugs, dizzy cap, icv, along with fuel supply have all been checked with no visible faults, along with air filter etc

from what i can find out something is telling the ecu, to either over fuel the car or to cut the fuel supply at the temp (no excess fuel smell and no backfire etc when trying to restart) or the ecu is not recieving the correct data back,

any idea what sensor could be at fault and any images of its location would be really helpfull?

 

[bolide]

AFAIK the 300-24 has a cold start valve which will enrich the mixture at low temps. Perhaps when the CSV drops out the mixture is too lean and the car stalls as a result?

I suspect the CSV has a wax thermostat but the ECU should have a temperature sender on the housing at the front of the head where the water pipe goes off to the rad

Every thread involving these cars has someone suggesting replacement of the distributor cap & rotor arm with MB parts. So I suggest you do that...

Nick Froome

 

[carat 3.6]

Welcome to the forum.

Have you checked if it is actully sparking when it cuts out? Can you hear the fuel pumps running?

Your dads car is fitted with a diagnostic socket, which can be used to read any fault codes in the system. It use'es old style flash codes instead of modern computer codes, you can buy a code reader on ebay for about £30.

 

[matt85]

hi, all plugs, leads etc have been replaced with genuine parts. as far i can tell its nothing to do with the ignition as the car doesnt miss-fire etc.

 

[ray_hennig]

hi, all plugs, leads etc have been replaced with genuine parts. as far i can tell its nothing to do with the ignition as the car doesnt miss-fire etc.

Plugs and leads. What else?

Your symptoms sound exactly what my new, cheapo rotor arm did. When was your rotor arm renewed and what make was the replacement?

R

 

[matt85]

plugs, rotor arm, dizzy cap are all bosch not sure on the leads though. but they are new and undamaged, no sign of corrosion on either end of the leads.
on a previous occasion it was checked for any signs of moisture inside the dizzy cap but there was no sign of moisture.

fuel filter, air filter, oil filter, rotor, dizzy, leads and plugs were all replaced 6 months ago.

its just strange that it cuts out in a very small temp range, below this temp it works perfectly and then above the temp it runs perfectly.

 

[Vlad]

Dont the 300-24v suffer from the EZL control unit breaking down?....may be worth an inspection, expecially as it cuts out when hot which is what tends to happpen when the EZL Unit gets hot.

 

[dsan]

Coil pack replaced?

 

[carat 3.6]

You need to rule out a problem with the ignition first, even though it dosent misfire and most parts are new, it can still be a spark issue.

Remove the plastic cover that hides the ht leads, and run the engine. When it cuts out, pull a plug lead off and insert a spare spark plug, now get someone to crank the engine while you touch the plug to earth. You will soon know if it is getting spark.

 

[matt85]

Coil pack replaced?

not that we are aware of, but will check

 

[dsan]

Had exactly the same issue with mine recently, replaced all ignition components and in the end it was the coil

 

[ray_hennig]

not that we are aware of, but will check

No 'coil packs' on this car, just the one ignition coil.

R

 

[mazza]

when the car is started from cold it runs perfectly right up untill it reaches around 82/83 degrees then it splutters and cuts out.

At what RPM ???

ECU receives temperature signals via the coolant temp sensor, as per Bolide's post.(check the condition of the wires).

Is this engine fitted with a LAMBDA/EZL?

Mazza

 

[jaymanek]

got to be a cold start issue...

 

[matt85]

im going to be bringing the car up to mine in the next few days hopefully the weather will stay nice, just going to go through and clean everything. i will most prob have a load of questions to ask lol

 

[219]

not that we are aware of, but will check

The 300-24 does not have a 'coil pack' ; it has a conventional ignition coil .

I had this very same problem with both my 300TE and my 300TE-24 , in each case a new set of spark plugs solved the problem .

As Bolide said earlier , these engines are prone to 'eat' distributor caps , but you have already changed this .

Next time it happens , pop in a new set of plugs and see if it makes any difference .

 

[grober]

http://www.mbclub.co.uk/forums/engine/86357-bosch-ke-jetronic-info.html I would begin to suspect the fuel pump relay which unfortunately is rather large and complex in these cars!

 

[neilrr]

http://www.mbclub.co.uk/forums/engine/86357-bosch-ke-jetronic-info.html I would begin to suspect the fuel pump relay which unfortunately is rather large and complex in these cars!

....and eye wateringly, stupidly, same-price-as-the-car expensive new from MB.

Should you need one I have a couple.

 

[brigadier]

Dont the 300-24v suffer from the EZL control unit breaking down?....may be worth an inspection, expecially as it cuts out when hot which is what tends to happpen when the EZL Unit gets hot.

I second that. Either ezl ar coil could do this when gets hot, and then run fine when cooled. I have a spare EZL and Coil lying around somewhere if you are somewhere near london we could swap them to see if it's them.

 

[grober]

I second that. Either ezl ar coil could do this when gets hot, and then run fine when cooled. I have a spare EZL and Coil lying around somewhere if you are somewhere near london we could swap them to see if it's them.

"
One test that can be done is to use an aerosol "freezer spray" [ the non conducting type ] on these units. {ezl or coil} If function is restored instantly rather than waiting for the longer cool down period that might be an indication of where the fault lies