72 280 sel stalling

[heylacy]

Hi, 1972 280 sel starts momentarally then stalls .Any ideas? Can hear pump run and when putting wire from batt. to coil, it also dies. Thanks for your help.

 

[television]

Does it always start and then stop every time you try.

Malcolm

 

[heylacy]

72 280 sel stalling

Hi, Yes, it starts but dies right away, even if the relay is bypassed. There also is no juice to relay thru key. I have to bypass relay to make pump run. Relay tests good. The power to relay from key is not there. The fuel pump fuse #4 is good. Are there other fuses between key and pump relay. Thank You for your help.

 

[television]

Sounds like a key barrel switch problem that is the piece that energizes Ign + pump
Whilst the contacts may be good when held over for the starter, when released it could lose contact. Common fault 90> Some people take them apart and adjust contacts

Malcolm

 

[heylacy]

Thanks, That sounds logical, When key is in on position everything under hood is powered up, could the bad contact fail just for the pump circuit ? I'll try it and see. Thank You

 

[heylacy]

Thanks, That sounds logical, When key is in on position everything under hood is powered up, could the bad contact fail just for the pump circuit ? I'll try it and see. What does [Common fault 90>] mean? Is that a trouble code that is set? Thank You

 

[television]

When you turn the key from position 2 to start it has what we call a wiping action, that is the contacts have to stay good from the start position back to position 2, any dead spot and the engine will cut as the relays opened.
I cant think of anything else. this fault is more apparent on the big cars due to the higher current drawn by large relays etc.

It could be a cold start problem go to www. Benzworld.org/forums then go to the W116.S.SE.SEL page half way down the page you will see Bosch jetronic, read that

Malcolm

 

[Mikesmerc]

Was there something about when the starter is engaged 12volts are ran directly to the ignition coil and when the key is released the current drops back down to 9 volts via a ceramic resistor located close to the coil itself. Could it be a faulty resistor? If a temporary live wire (12v) was ran to the coil and she still stalled this would eliminate my faulty resistor theory.
Mike

 

[television]

The use of a ballast ressistor was mainly dropped with the introduction of transistorised ign, not sure at this point on this car, but I had not thought of that.
If his ign is OK, I have been thinking about the fuel enrichment device as the fault may not have have shown till the start of the cold weather.

Malcolm

 

[heylacy]

Hi, Yes, this car has 2 resisters and both tested good. At 12 volts with jumper wire from batt. it still stalls. Thanks for your input. I'm working on it alone when I get time and it's freezing out today. I think I'll try to check the tumbler out and see if that is it. Is there any way that there could be a relay between ignition switch and pump relay?

 

[dogsbody]

If the relay is bypassed are you sure you have not got a duff coil?
Had similar some years ago - alright a hell of a time ago on an Austin Cambridge, which would start and run for 90 secs then die.
Turned out to be a broken wire in the coil winding which was closed circuit when cold, but as soon as it got warm it went open circuit - just a thought

 

[heylacy]

Hi, Well today I checked and found out that the injectors are not letting fuel into engine. I used a noid light. The car starts but dies because of no fuel. Fuel pressure is #21lbs. spark is good and steady. Tumbler is good. Any ideas what to check next? Either Computor drivers are not being told to fire injectors or computor is bad. Could the fuel shut off relay be bad? Or trans switch for decel.? Thank you

 

[heylacy]

Hi, It is a 108 with 4.5 v8 and automatic trans. Today I went out there and it started right up and had a steady noid light on injector harness. Put it from park and it died and now I have no power to injectors again to run past start cycle. While it was running, it ran fine. I am puzzled really bad now. An intermitant problem is very hard to solve. Plug at distibuter is good and clean. Thanks for any help anyone can give.

 

[guydewdney]

Where are you based - I have a paper manual I made about the D Jetronic system that is on your car - its all from the 'web - but it took a lot of searching....

a) try a search on D jetronic or Djet on google (porche use the same system)
b) check all wiring - there isnt a lot..
c) buy one of mine...

 

[television]

Can you please tell me what the injection system is on your car and the engine ie 110?

Malcolm

 

[television]

Bocsh D and K Starts, then stops when key released

I think you have the the D or K
If it starts and stops when you release Key , you may find the problem is the trigger points in the distributor, could be starting from the cold start injector and as soon as release key the cold start injector shuts off.

Malcolm

 

[heylacy]

Trigger points

Hi,Thats what it looks like at this time. Does anyone know how to tell if it is the points? The car started right up the other day. Would the trigger point problem be intermittant like that? Do I have to pull distributor to diag. points or can I probe the computor connections plug? Where can I get a guide to do this?

 

[television]

The trigger points are below the ign points. If you want 28 pages of how to test and set up go to www.benzworld go to forums then 116 half way down the page you will see Bocsh D and K trouble shooting.

Malcolm

 

[heylacy]

Thank you, I found the problem! Someone extended a wire from the batt to computor harness. After prayer and investigating , I found a very bad connection which was not allowing 12 volts to computor feed. After replacing wire and new end ,car works fine now. This one faulty hidden homemade rigged connection sure caused a lot of trouble.Thank you all for your help.