1987 230E Automatic, New member seeks help please.

[tankie1rtr]

Hi All.
I am a new member to the Mercedes club, and was advised that if I joined that I may be able to find some help. I bought a 1987 Merc 230E, I have had her about 2 years and every morning she has started first time, recently I go out to start her up but she will not fire, after a few attemps she will run but only at very low revs, I have to leave her runninf for about 2 mins then slowly increase the revs, then she runs fine, once warm she is wonderful, leave her fr a few hours (7) and I have the same trouble all over again, I have checked the 10amp fuse on top of the relay behind the panle behind the battery and the fuse is fine, I have had a new inline petrol filter put on a few weeks ago thats fine. I am at a loss, If anybody has got any suggestions It would be very much appreciated.
Thank You

 

[tjo]

the relay your talkin about is the over voltage relay, altho u've tried fuse the relay its self could b faulty, it controls various systems includin cold start,

 

[television]

Though the fuse mybe OK you do need to check with a voltmeter that you have 12volt going into pin30 and 12volt on the 87 pins you may have two 87 pins. if you only have around 7.5 volt it will shut off your starting and idle circuits.

Malcolm

 

[tankie1rtr]

Help.

Thank You, I will find someone who will test it for me, When I bought the car 12 months ago, I had trouble starting it and I found out that the fuse had blown on top of the relay, I telephoned the guy and he said he had trouble for the last 18 months starting it, he did not know about the fuse. I am wondering if he had trouble for so long if it has damaged the relay.
Regards
JOhn

 

[markjf]

It's not too bad to check yourself if you want to.

Malcolm (Television) told me about this and with some help from John T, I did it myself. This is how I did it.

1. Disconnect the battery (+) and then release the metal clip on the housing where the computers sit. This is on the left hand side of the housing and behind the battery which holds the housing together. You need to release this clip to allow some breathing space.

2. Release the clips for long shaped plugs on top of the computers which sit behind the battery and remove them from the computers. These are horizontal when looking at the car from the front and you may find you need to wiglle a bit to get them off. (One of the release clips is one side and other other is the opposite)

3. Remove each of the computers. You can't get them mixed up but the samller of the two is the one behind.

4. Then remove the housing. This is held in with three 8mm bolts. Two are at the top facing the front and the other is at the front/bottom/facing downwards. You will also need to slide the relay out at the same time as this is sloted in the side of the housing.

5. Move the housing toward the side of the car and give it a little twist so you can see the relay more clearly.

6. Disconnect the relay from the loom and look underneath. You will see pins 87 as they are numbered.

7. Take a note of where they are when plugged into the loom and push the relay back in leaving a gap for a volt meter probe to make contact with the pins.

8. Plug the computers back in and place them in a safe position and away from the battery terminals!

9. Reconnect the battery

10. Attach the negative lead on the volt meter to the battery earth and test you have 12 volts by making contact with the positive lead on the volt meter with the positive terminal on the battery.

11. Re-visit the relay and make contact with pin(s) 87 to check that 12 volts is reading on the volt meter from both of the pins.

12. Once tested either put it back together or fit the new relay!!

Malcolm (Television said that if one of the readings is 7.5 volts from these pins that this is where the problem will lye.

I hope this helps? It's a bit of a mine field but there are some helpful people within the forum who are happy to help. Good luck.

Regards,

Mark

 

[tankie1rtr]

OVP Relay test

Hi Mark.
Thanks for the info, I have printed it and I will get the sparky at work to help me with it, seems a long job, hope it sorts it out. Many Thanks for your help.
Regards
John

 

[markjf]

John

I would say half an hour max including putting it back but if you are not confident with what you are doing I would say 45 minutes to be safe.

Regards,

Mark

 

[tankie1rtr]

tjo. television, and markjf.

Just want to thank you all for your help. I went to Mercedes and just bought an APO relay and put it on, and the problem was cured right away, Once again thanks for the help, and I will raise a glass of whisky in your favour tonight, Great site, great people