GT-150 Odd random spark returns

[qcernie]

Well, I thought I had this solved by replacing a kill switch but it's reared it's ugly head again. I have a 1990 GT-150 crossfire. At times I have no spark, confirmed with spark tester. When that happens, I can unplug the big red plug, jump the solenoid and I get good spark. Then without touching anything else, I plug the red connector back in and I still have good spark. This happens randomly. When I lose spark, I go through the above procedure and it works every time. I have replaced the wiring harness from the switch to the motor. I'm starting to think the problem is a short in the motor wiring harness. Any ideas? Could the solenoid cause this if it's going bad?

 

[Daviet]

Re: GT-150 Odd random spark returns

Use an ohm meter and check the kill wire on the engine side of the harness and see if it is grounded.

 

[qcernie]

Re: GT-150 Odd random spark returns

I'll have to wait until the no spark returns to test the kill wire. It's decided to run now.

 

[Faztbullet]

Re: GT-150 Odd random spark returns

The "T" packs on these engines was troublesome from day 1 and will cause goofy problems like you have posted..

 

[emdsapmgr]

Re: GT-150 Odd random spark returns

Also check the key switch in the control box. If they ever get water in them, they can act up.

 

[keefallan]

Re: GT-150 Odd random spark returns

Have you ever gotten the weak or no spark condition with the harness unplugged? My thoughts are this: If you can get a no spark condition with the wiring harness disconnected, then the problem is at the motor. If you can't ever reproduce the no spark with it dis connected, then it's more likely to be at the helm or the wiring harness to the helm. Hope that helps.

 

[qcernie]

Re: GT-150 Odd random spark returns

Faztbullet, do you mean the Power pack (this model only has 1).
Key switch test good.
It always has spark with the harness unplugged. The strange thing is when I plug the harness back in, I still have spark.

 

[emdsapmgr]

Re: GT-150 Odd random spark returns

The solenoid is part of the start system, not part of the ignition system. That ignition system requires that the engine turn at least 250 rpm's when cranking in order to develop enough current to fire the ignition. If you have a weak battery, starter solenoid or starter, that could cause slow cranking and a "no spark" problem.

 

[qcernie]

Re: GT-150 Odd random spark returns

This afternoon, no spark. I checked the kill wires to the pack. Not grounded. Disconnected the kill wires from the pack still no spark. Reconnected the kill wires to the pack, now have spark. This is starting to resemble a twilight zone episode.

 

[James R]

Re: GT-150 Odd random spark returns

Sounds like a powerpack problem, however before you go spending money check that all the grounds are clean and tight and then you will have to do resistance checks on the stator and trigger to at least have a chance of being correct on the powerpack failure. Plug in "CDI trouble shooting" for testing info

 

[qcernie]

Re: GT-150 Odd random spark returns

It's not consistent with what I've read about power pack failures. However, I may be on to something. At 80% my cranking battery is 12.2 volts and no spark. At full charge the battery is at 13.6 volts and good spark. Because of the drought here in Texas, I've been fishing mainly in power plant lakes. They tend to be smaller. Also these crossfires are not the easiest motors to start. I'm thinking that I'm not running the motor long enough on the water to recharge the battery after cranking. I checked the battery terminals with the motor running and get 14.6 volts, so the regulator/rectifier is working. Any thoughts on this theory?

 

[emdsapmgr]

Re: GT-150 Odd random spark returns

At 14.6 volts, sounds like the charging system is working ok.