5.7 GLi code 42 and tach inop

fisherman73

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After reinstalling my motor for an upper end rebuild etc it started right up and all appeared normal. I connected my code tool and set the base timing and locked down the distributor. I removed the code tool and started it back up. I noticed at that point that the tach which was definetely working before setting the timing was sitting on 0. I hooked up the code tool and am getting a code 42 est ground fault. I followed the flow chart in the service manual which showed that the module was not grounding the IC bypass wire, continuity of the wire proved good. My first thought was that the distributor ground was weak, especially because everything has a new coat of paint on it. I added a reduntant ground to the distibutor but no change was noted. I checked voltage on the pulse wire to the tach and was getting a little over 13 volts. I disconnected the wire at the tach and found that the voltage is coming from the pulse wire out of the coil. Im more than a little confused by this because the engine runs fine and appears to be going into est mode normally. Of course Im not entirely sure that the tach and the code 42 have anything to do with each other.
 

fisherman73

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Messages
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Re: 5.7 GLi code 42 and tach inop

Oh I forgot to add that also tried a new ignition module as well..... no change. Any one have any ideas on why Im getting over 13 volts on my tach pulse wire or where to go with the code 42 ?
 

Don S

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Re: 5.7 GLi code 42 and tach inop

Motor model # 57FDPLKD Motor s/n T1298254

I got the above numbers off of one of your other posts, and those are OMC numbers, not Volvo.
So where did this GLi come from? and if it is a Volvo, what are the rest of the letters after the GLi?
 

fisherman73

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Messages
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Re: 5.7 GLi code 42 and tach inop

5.7GLiPLKDCE. Im sure you have alot more knowledge about it than I do, but from what I understand these joint venture Volvo/OMC SX Cobras can be a bit confusing as to who made what and when.
 

Don S

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Re: 5.7 GLi code 42 and tach inop

The LK determins the when (1997 year model) and there are some differences in the way they are setup between OMC and Volvo.
Which is why I wanted to know what you had. Which do you really have OMC or Volvo version, you are using both model numbers and it's a bit confusing.
You mention you had a code 42 est ground fault. but that isn't what the Volvo manual calls a 42 fault. Where did the "est ground fault" come from? Omc manual perhaps?
 

fisherman73

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Messages
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Re: 5.7 GLi code 42 and tach inop

Ahh! Well that is a curious thing. Yes it is a 1997 year boat. The motor does not say OMC on it anywhere. It it labeled as a Volvo Penta
5.7Gli with a VP SX Cobra drive. The first numbers you gave from my previous post are the numbers off of the tag on the motor. The second numbers are numbers you came up with on my very 1st thread here. Yes I am using OMC manuals. What does VP say 42 is ? I am a service manager at a GM dealership so I am very familiar with 42 as being an EST ground issue.
 

fisherman73

Petty Officer 3rd Class
Joined
Aug 12, 2005
Messages
94
Re: 5.7 GLi code 42 and tach inop

After studying the wiring diagram for the ignition circuit I guess I could hypothosize why I am reading ignition voltage on the tach lead. The signal of course would be pulsing if I were to look at it with an osciloscope Im sure but it would be pulling ignition voltage through the primary coil winding. Perhaps my tach just went belly up.
 
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