coil wire volts

[boston_jake01]

I have a electronic ignition volvo AQ271C and I have been having problems withit running crappy at wot after it runs for a while and at low idle when i first start it. I did the coil + lead test as it mentions in the repair manual and it was 9.5 - 10 volt with the sensor not lined as it said to do in the book... any ideas what could cause the low volts?
Batteries are fully charged and read 12 volt the book said the coil should not be more than 1 volt drop in the + lead of the coil
thanks

 

[b00tstrap]

Re: coil wire volts

If the coil is bad, the dielectric may be breaking down and you will have a voltage leak. The coil should be replaced in my opinion. Obviously all the connections should be clean and intact.

 

[Don S]

Re: coil wire volts

What BOOK are you looking at, you should be showing battery voltage at the + terminal on the coil with the ignition switch in the on postion. (engine not running), and a fully charged battery better be more than 12V.

 

[bruceb58]

Re: coil wire volts

This may be a stupid question but did AQ271C engines have electronic ignition?

 

[Dunaruna]

Re: coil wire volts

[colour=blue]Sure did, factory fitted.

 

[Reel Poor]

Re: coil wire volts

Disconnect the + feed wire from the coil and check voltage again. If you now have battery voltage reconnect it to the coil and disconnect the - side wires then recheck + voltage reading. If low replace coil. If battery voltage is present diagnose tach problem or pick up module problem.

 

[boston_jake01]

Re: coil wire volts

1. The coil is new.
2. the book is selocvolvo penta repair manual
3. " Disconnect the + feed wire from the coil and check voltage again. If you now have battery voltage reconnect it to the coil and disconnect the - side wires then recheck + voltage reading. If low replace coil. If battery voltage is present diagnose tach problem or pick up module problem. " what side wires are you talking about? I have three positive lead wires 1. from alt., 2. from speed limiter, 3. choke.
4. the batteries read 12.5 volts is this ok?
Thanks

 

[Don S]

Re: coil wire volts

Disconnect the speed limiter and see how it runs. Forgot about those things.
Might also check all the connections on the purple wire from the ignition switch to the coil. (Including the harness plugs). Corrosion or loose connections will also cause your voltage drop.

 

[Reel Poor]

Re: coil wire volts

If you now have battery voltage reconnect it to the coil and disconnect the - side wires then recheck + voltage reading.

- = negative
+ = Positive

So it should read, If you now have battery voltage reconnect it to the coil and disconnect the negative side wires then recheck positive voltage reading.

 

[boston_jake01]

Re: coil wire volts

I tryed disconnecting the purple wire from the speed limiter and it shut off I donn't know if thats normal? or should I disconnect the other wires to the speed limiter?
I checked the purple wire connection at the alternator, wiring harness plug, ignition switch, I tryed to unplug the other wiring harness plug that is clamped but was unable to unplug itis there something else I should do???
also what should the coil read when the neg. side is disconnected 0? because the ground is off?

 

[Reel Poor]

Re: coil wire volts

With the neg side disconnected the pos side should read battery voltage. If it doesn't replace the coil.

With the neg side disconnected and the pos side connected test the neg side, should be within 2 volts of battery voltage (probably within 1 volt).

As for the speed limiter, remove it from the system and connect the pos lead from the ignition switch (purple wire) to the pos side of the coil.

 

[b00tstrap]

Re: coil wire volts

Take your multimeter and check the voltage of your battery at the posts (red wire to positive "+" terminal and black wire to negative "-" terminal) record the reading.

Now go to your coil and disconnect the negative "-" side wires. Put the red lead of your meter on the negative side "-" of the coil, and the black wire of your meter to a good ground (like the "-" side of the battery again). The theory is that the voltage should not drop across the coil more than 1volt, so compare this reading to the original one.