89 300SE ignition coil prob/question

I'm sure someone can enlighten me here.

Have had a recurring problem with starting and misfiring (noticeable at idle). Anyway it won't start now, but does cough whilst cranking and tries to run after releasing the starter. I can hear the fuel pump run when I switch on, and its still running a second or two after I finish cranking. I can also smell fuel after some considerable attempts to start, so I'm dismissing that for now. I did a bit of poking around in the HT area. Despite the dire warnings in the manual, I disconnected the HT lead output from the coil and put another suppressed lead into the top of the coil and placed it so that its outlet could spark to the car and I could see it whilst cranking the engine. Of note was the brilliant yellowy orange colour of the spark. I was expecting a nice bright blue spark. In now way could you call what I had blue. I beleive this is wrong. I realise that I could have a problem with the ignition ECU, but avoiding that at the moment (have you seen the price of these things), I thought it would be easiest to swap in another coil. It looks straight forward enough. I have another disimilar coil here, of low resistance also. However I looked up the replacement parts supplier list on the web, and they show two coils. One with ABS and one without. Now unless I'm missing something glaringly obvious, what does the ignition coil have to do with the ABS. In fact, what does any of the ignition system have to do with the ABS, except to tell it that the engine is running via the tacho signal. Seems wrong to me. I did notice that the 'non' ABS coil was considerably cheaper than the BOSCH 'with' ABS coil. Are they trying to sell the expensive part snce most cars are with ABS?

Any ideas?

Cheers... Rob.

Reply to
Rob. Smith
Loading thread data ...

Check the spark plug wires resistance... all should be less than 1200 ohm.

Check and replace the OVP Relay.

Reply to
Tiger

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.