JustJason
Vice Admiral
- Joined
- Aug 27, 2007
- Messages
- 5,320
I was wondering if any seasoned j/rude techs could shoot a few pointers into diagnosing an OIS ignition on a 92-93ish J150 with a jet.
Here's what a got.
Got called out to the job because the engine did not start. (slow cranking/no starting)
I was losing a volt + across both the positive and the negative battery cables (a volt each) from the battery to the engine. (doing a voltage drop test.. fluke meter)
Replaced both cables, retested, voltage drop now less than .4VDC across the whole system. Starter still slow. Amp clamped it and starter had 250amp nominal draw (not peak) I am going to send the starter to the rebuild shop tomorrow. (typical that the bad cables caused the drop which caused the starter to pile on the amps and go whamo)
here is where i stand.
No spark on all.
disconnected kill wire at pack, still no spark.
meter show's impedence to be in spec but dva #'s are below/way to low. But the cranking speed is only, and this is a guess, 3-4 hundred rpm.
I do not have the service manual but i have the rapair ignition bible. (have never failed me yet)
This manual says that the OIS sensor and packs must see 11+ volts at cranking speed or it will not function. (yellow/red wire, off str sol) Can anybody confirm if this is accurate. Most efi's will go down to 9.5vdc before they shut down. 11 "seems" a bit high, but it's a johnson so i'll bite. i'm going getting close to 9 at cranking, but at a 250 amp draw the starter is eating all my current/voltage.
No spark with reg/rect disconected either.
What i do have: brains, the rapair bible, high quality multimeters and dva adaptors, and a degree in marine technology
what i don't have: the j/rude test tool for testing the OIS or a sillyscope for the same function.
Any tips a salty dog could give would be much appreciated
Here's what a got.
Got called out to the job because the engine did not start. (slow cranking/no starting)
I was losing a volt + across both the positive and the negative battery cables (a volt each) from the battery to the engine. (doing a voltage drop test.. fluke meter)
Replaced both cables, retested, voltage drop now less than .4VDC across the whole system. Starter still slow. Amp clamped it and starter had 250amp nominal draw (not peak) I am going to send the starter to the rebuild shop tomorrow. (typical that the bad cables caused the drop which caused the starter to pile on the amps and go whamo)
here is where i stand.
No spark on all.
disconnected kill wire at pack, still no spark.
meter show's impedence to be in spec but dva #'s are below/way to low. But the cranking speed is only, and this is a guess, 3-4 hundred rpm.
I do not have the service manual but i have the rapair ignition bible. (have never failed me yet)
This manual says that the OIS sensor and packs must see 11+ volts at cranking speed or it will not function. (yellow/red wire, off str sol) Can anybody confirm if this is accurate. Most efi's will go down to 9.5vdc before they shut down. 11 "seems" a bit high, but it's a johnson so i'll bite. i'm going getting close to 9 at cranking, but at a 250 amp draw the starter is eating all my current/voltage.
No spark with reg/rect disconected either.
What i do have: brains, the rapair bible, high quality multimeters and dva adaptors, and a degree in marine technology
what i don't have: the j/rude test tool for testing the OIS or a sillyscope for the same function.
Any tips a salty dog could give would be much appreciated