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Discussion Starter #1
Hi,

I have my 87 560SL parked outside for 2 weeks and now it won't start. I have spark, I hear the fuel pump but my tachometer and speedometer move very weird as i"m cranking the engine, I have never noticed this and I think that is strange. I do have an extra grounding wire in my instrument cluster, i did this when I change the odometer gears last year.

Anyway it doesn't start, next on my list is to measure the coil (although I have spark). I have had the car for quite a number of years and I believe it is the original coil. If I order this I will also order a fuel pump relay as I see that this can cause all sort of problems and finaly I will check the this wire at the battery.

Any guidance before ordering new parts?

Thanks,
Eric
 

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Hi,

I have my 87 560SL parked outside for 2 weeks and now it won't start. I have spark, I hear the fuel pump but my tachometer and speedometer move very weird as i"m cranking the engine, I have never noticed this and I think that is strange. I do have an extra grounding wire in my instrument cluster, i did this when I change the odometer gears last year.

Anyway it doesn't start, next on my list is to measure the coil (although I have spark). I have had the car for quite a number of years and I believe it is the original coil. If I order this I will also order a fuel pump relay as I see that this can cause all sort of problems and finaly I will check the this wire at the battery.

Any guidance before ordering new parts?

Thanks,
Eric
Uh... How do you know you have spark? You didn't remove the coil wire and try cranking, did you?

I'm thinking the worst... EZL, but could be CPS, etc. Just be damned sure NOT to try cranking with the coil removed, or I KNOW it (will be) is the EZL. If in question, ask member, dugald :) (sorry duggie).
 

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Discussion Starter #3
Uh... How do you know you have spark? You didn't remove the coil wire and try cranking, did you?

I'm thinking the worst... EZL, but could be CPS, etc. Just be damned sure NOT to try cranking with the coil removed, or I KNOW it (will be) is the EZL. If in question, ask member, dugald :) (sorry duggie).
Hi, I removed a spark plug and checked.
Thanks
 

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Hi, I removed a spark plug and checked.
Thanks
Still not the safest way to check for spark with these engines, but you probably got away with it. If you had spark, I guess you have a functioning EZL and CPS... At this point, I am clueless. Sorry...

Incidentally, how did you determine you have fuel at the distributor? The injectors?
 

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Still not the safest way to check for spark with these engines, but you probably got away with it. If you had spark, I guess you have a functioning EZL and CPS... At this point, I am clueless. Sorry...

Incidentally, how did you determine you have fuel at the distributor? The injectors?
I haven't checked if I have fuel at the injectors, I know the fuel pump is running that's all, is there an easy way to check?
 

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I haven't checked if I have fuel at the injectors, I know the fuel pump is running that's all, is there an easy way to check?
Well, easy is a judgement call. There are a number of ways. Of course, the recommended way is to attach a set of gauges and measure while you're at it. You MIGHT can disconnect the cold-start injector and turn on the key, but this would tell you nothing about the pressure. It takes, I forget, 30-40? psi to open the injectors. Be sure you use some kind of vessel to catch the fuel, and have a helper turn on the key... and safeguard for fire.

Remember, the 560 uses two fuel pumps to get the job done, volume and pressure-wise. The engine reportedly will NOT run on one only. Electrical fault cannot be ruled out, as the FPR also takes a rpm indicator in order to shut down if engine quits running, and the rpm limiter is also built in to the FPR on a 560...
 

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Because of the strange behavior of the guages could the OVP relay be suspect?
I have not heard of an OVP causing NO-Start condition; however, when mine failed on my '88, it took a while of cranking to get it to start...

Looking at the wiring diagram, you bring up a good point. Worth a check for sure, and not too expensive.
 

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Discussion Starter #9
I have not heard of an OVP causing NO-Start condition; however, when mine failed on my '88, it took a while of cranking to get it to start...

Looking at the wiring diagram, you bring up a good point. Worth a check for sure, and not too expensive.
I did have a new OVP installed about a year ago to overcome the ABS light on problem (didn't help, need to check the sensors)

I can try the old one again.

On the fuel pressure and checking if I get fuel, I can do that tomorrow.

Thanks so far,
Eric
 

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I haven't checked if I have fuel at the injectors, I know the fuel pump is running that's all, is there an easy way to check?
A can of starting fluid?


Here is what you do, spray it in, if it starts its not getting fuel, if it doesn't start its not getting spark.






Also you can use a regular test light to test the injector (elect) fire control. Just unplug the connector, turn the key on, find which one is full time hot. Now keep in mind which one is hot, you WILL not be testing that again.

On the other side of the connector is the fire control from the ECM, it is a (-) circuit.

Now take your test light and hook the clipped end to the Battery (+), yes the positive. Then with the pointy end of the probe, probe the (-) circuit side of the connector side of the injector your checking. (remembering which one is (+) and (-).

Have someone crank it, if it lights up in flash's, it works, if it doesn't, its not being told too by the Computer. Computer has no power, bad fuse, wiring whatever the case may be, bad cam sensor?







But a can of starting fluid will point you in the right direction.



Oh too, the test light bulb might flash dimmer then you would expect, but it will flash.
 

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Thank you so far, I will do some checks tomorrow evening, did anybody find the bouncy tach and speedo not strange....

Eric
Hey Eric, I am right up the street from you in Frisco. If you need an extra hand or someone to drink beer with while wrenching, let me know.

Steve
 

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Discussion Starter #15
Hey Eric, I am right up the street from you in Frisco. If you need an extra hand or someone to drink beer with while wrenching, let me know.

Steve
Thanks Steve, will do. I will send a PM.

By the way, I got the car to run this morning, used some starter spray, although something else happened, the alarm went on and could not get it off anymore, I had to disconnect it behind the glove box. Afterwards it would start but takes some cranking to do so, also the engine does not run as smooth as it did before.

It seems my car got "a cold" by being parked outside. I would almost think that I may have some fuel and electric problems, I have read here on the forum about possible shorts in the alarm. And fuel related since the starter spray did help.

Maybe time to do some maintenance, I'm now thinking of replacing, fuel filter and pumps, FPR, ignition coil (did wires and dist, etc last year), check the alarm wires at the doors for shorts, and the hood liner is also falling apart.

I'm expecting that these parts are all still original since 87, so it is about time.

Eric
 
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