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Discussion Starter · #1 ·
I posted a little while back that I destroyed my cap and rotor, and got a good replacement. Thank you again. But oddly there is no spark from the coil. (Replaced). Still nothing after checking wires connections, and other systems like fuses and relays. Am I missing something?
 

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what is the battery voltage?
next, what is voltage when you are cranking? (ECU needs 10,5V+ 'during cranking' to even wake up)

if battery voltage is good (12.6V+) and cranking voltage is above 10,5V then next check would be, is there battery voltage at the coil (Key on, coil positive to ground)

yes?
then next check would be your flywheel sensors.
 

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There should be one spaghetti wire from one of the coil terminals to the distributor.. If that wire is not connected properly and have continuity there will not be spark at the points.. a condenser is on the connection at the body of the distributor too and is isolated with a phenolic buffer from the body of the distrubutor
 

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his is L-jet

doubt it has spaghetti wire, points or condenser;)

and exactly why members should put the model in their signature or at least say this is my '82 or my '76.....or whatever.....when they post.
If you went by my avatar you'd think I was on about a 101 sprint or a Jag:)
 

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Discussion Starter · #5 ·
what is the battery voltage?
next, what is voltage when you are cranking? (ECU needs 10,5V+ 'during cranking' to even wake up)

if battery voltage is good (12.6V+) and cranking voltage is above 10,5V then next check would be, is there battery voltage at the coil (Key on, coil positive to ground)

yes?
then next check would be your flywheel sensors.
Did not know about the flywheel sensor. Excellent charger and has power. I'll look at connections and grounds again. Thank you
 

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Discussion Starter · #6 ·
his is L-jet

doubt it has spaghetti wire, points or condenser;)

and exactly why members should put the model in their signature or at least say this is my '82 or my '76.....or whatever.....when they post.
If you went by my avatar you'd think I was on about a 101 sprint or a Jag:)
Apologies, to be more specific its an '87 Spider Veloce, without a condenser attached
 

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Discussion Starter · #7 ·
There should be one spaghetti wire from one of the coil terminals to the distributor.. If that wire is not connected properly and have continuity there will not be spark at the points.. a condenser is on the connection at the body of the distributor too and is isolated with a phenolic buffer from the body of the distrubutor
Weird, it is an L-jet with and empty distributor, on points no condenser...unless I destroyed all that too.
 

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Weird, it is an L-jet with and empty distributor, on points no condenser...unless I destroyed all that too.
You didn't destroy anything. The L-jetronic ignition timing is all computer controlled. The distributor is just that - a four way switch that distributes the coil output to the appropriate spark plug.

Click the down arrow over on the right to see my signature. There is a link there to a page of DIY Diagnosis of the L-jetronic Spider.
 

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Maybe check if the distributor is turning. Could be the shaft is snapped
 

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Discussion Starter · #10 ·
Ok more diagnostic info on my 87 Spider Veloce. Removed the 2 +POS wires on the coil and checked individually. The black/blue wire has power with key on. The black/green wire has no power key on or cranking. Is there suppose to be power to it? And where does it go from the coil? Still no spark from the coil.
 

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Ok more diagnostic info on my 87 Spider Veloce. Removed the 2 +POS wires on the coil and checked individually. The black/blue wire has power with key on. The black/green wire has no power key on or cranking. Is there suppose to be power to it? And where does it go from the coil? Still no spark from the coil.
As a rule, yes... otherwise they wouldn't be necessary
 

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Ok more diagnostic info on my 87 Spider Veloce. Removed the 2 +POS wires on the coil and checked individually. The black/blue wire has power with key on. The black/green wire has no power key on or cranking. Is there suppose to be power to it? And where does it go from the coil? Still no spark from the coil.
black/blue?
probably a black/green and the green has faded to blue;)

one black/green is power from hot side of fuse #7, so yes 12v with KO
the other black/green is to the solenoid VVT (via the 8A bullet fuse)......so if you are testing for power with it removed from coil, there is none.


you have power at the coil positive, but you do not have a pulse. Battery is good and cranking voltage is excellent (you say)
so...
I still say check the flywheel sensors before digging in any deeper on this....and not only for OHMS as the jetronic guide says (they might read correct and still not function), but also for 'signal', which can be done with a voltmeter set to AC Volts
 

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On the coil, the primary coil + post should have 12v (battery voltage) with key on, and when engine is cranking. The other coil primary post, coil - should pulse when cranking (and when engine is running). This on-off pulse comes from the ignition ECU. Check these coil terminals with a test light. Looks like a screwdriver with a light bulb in the handle, and a single wire with an alligator clip on the end to attach to a good ground. POWER PROBE makes an upgraded tool like this with a rocker switch and LED lights. THE BEST TOOL for diagnosing simple electrical faults. When doing these tests, have an ignition wire attached to the secondary coil output (the coil wire hole in the middle) and a spark checking tool at the end of the wire. A spark plug attached to the wire and laying up against the cylinder head or cam cover will work too. Also, remember that when you do all this cranking to check the spark, the injectors are firing and adding fuel into the engine. This can cause fuel fouled spark plugs, and washed-down cylinder walls; both of which may cause the engine to not start even after you repair your spark issue. Disable the fuel pump to stop the fuel injection.
 
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Discussion Starter · #15 ·
black/blue?
probably a black/green and the green has faded to blue;)

one black/green is power from hot side of fuse #7, so yes 12v with KO
the other black/green is to the solenoid VVT (via the 8A bullet fuse)......so if you are testing for power with it removed from coil, there is none.


you have power at the coil positive, but you do not have a pulse. Battery is good and cranking voltage is excellent (you say)
so...
I still say check the flywheel sensors before digging in any deeper on this....and not only for OHMS as the jetronic guide says (they might read correct and still not function), but also for 'signal', which can be done with a voltmeter set to AC Volts
Hello Sir, I checked the sensor and the OHMS read .97. Which was good. However, I have this issue with someone cranking a vehicle while its on jack stands. So I'll just replace it. Besides, the wire is quite stiff and rotted. This was an original part. Thanks, I'll let you know how it turns out. And we have people from all over the US with big trucks and RVs here for Cheyenne Frontier Days. Best I keep my little gem off the roads for the next 10 days.
 

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Discussion Starter · #16 ·
On the coil, the primary coil + post should have 12v (battery voltage) with key on, and when engine is cranking. The other coil primary post, coil - should pulse when cranking (and when engine is running). This on-off pulse comes from the ignition ECU. Check these coil terminals with a test light. Looks like a screwdriver with a light bulb in the handle, and a single wire with an alligator clip on the end to attach to a good ground. POWER PROBE makes an upgraded tool like this with a rocker switch and LED lights. THE BEST TOOL for diagnosing simple electrical faults. When doing these tests, have an ignition wire attached to the secondary coil output (the coil wire hole in the middle) and a spark checking tool at the end of the wire. A spark plug attached to the wire and laying up against the cylinder head or cam cover will work too. Also, remember that when you do all this cranking to check the spark, the injectors are firing and adding fuel into the engine. This can cause fuel fouled spark plugs, and washed-down cylinder walls; both of which may cause the engine to not start even after you repair your spark issue. Disable the fuel pump to stop the fuel injection.
No pulse from the second wire. Tried that last night. so I'm just going to replace the flywheel sensor, It was original like the other 88% of the vehicle. Thanks for your help.
 

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I checked the sensor and the OHMS read .97. Which was good. However, I have this issue with someone cranking a vehicle while its on jack stands. So I'll just replace it.
you checked both, I presume.., there are two, both are important, one for fuel one for ignition

(yes, I understand not wanting to crank on jackstands, but it should be no problem if they are properly placed and the car in neutral.
What one can do to make things safer, is remove all spark plugs, then when you crank there is no torquing of the engine due to zero compression)
 
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