Testing Thurderbolt IV ignition

[13crazyhorse]

I just bought a 86 four winns with a 350 engine. I don't have any spark. I've got the chart on how to diagnose this. I got down to where it says remove high tension lead from distributor to coil. Insert a spark gap tester from coil wire to ground. Remove wht/grn lead from distributor terminal - ignition key in run position. Strike the terminal on the wht/grn lead against ground. I have a couple of questions. I have a spark plug spark tester that plugs on a plug and then into the plug boot is that the same? I don't understand how this would hook to the coil? Can I just use a wire with alligator clips to ground the coil? Then I already removed one wht/grn wire from the dist in a previous step that went to the interrupter switch but there's one left I assume that's the one to remove. Then I strike the removed wire against a ground? It says one way there will be spark at the coil and one way there will be none? I'm missing something, please explain for the dummy! Thanks ahead of time for your help.

 

[dingdongs]

Re: Testing Thurderbolt IV ignition

pull the lead that goes to the centre of the distributer leave the other end still in the coil and

plugyour spark tester into this lead and you will be holding next to ground.
seperate the green/white wire and rapidly strike to ground,maybe 4 to 5 times per second.
if you have spark the sensor will require replacement.
this method above is taking the sensor out of the equation and falsifying what would have been the signal.
the ignition has to be on too.

 

[13crazyhorse]

Re: Testing Thurderbolt IV ignition

Ok thanks for your reply. I took the coil lead off the dist cap and put my plug tester in the end of the wire still attached to the coil and set the other end on a stud end to ground it. When I turned the ignition key on I get one big bright flash in the plug tester. Now I take that grn/wht wire off the dist and rapidly ground it, nothing. I would assume by my chart that I need a new ignition module?

 

[dingdongs]

Re: Testing Thurderbolt IV ignition




do you have a multimeter to prove what voltages are available and where????????

 

[13crazyhorse]

Re: Testing Thurderbolt IV ignition

Yes I do have a multimeter and have checked the voltage at the coil (10-12), I have voltage at the wht/red wire at the dist (10-12). There are two wht/grn leads to the same terminal at the dist, I unhooked the one that looks like it goes to the interrupter switch and checked the other one against ground, no spark in my tester. I should check the other one just to be safe. It says on the chart they should be bullet connectors but all wires are hooked to screws at the dist. I don't think that make a difference though. Want to make sure of the problem as you know big money to fix this. I'm thinking maybe from my research the Delco Voyager EST system would be the way to go. Costs 350 but you get everything replaced, dist, wires, module, etc. my system is over 25 yrs old.

 

[13crazyhorse]

Re: Testing Thurderbolt IV ignition

Well I just went online to Michiganmotorz and ordered a new Delco dist kit. Hopefully by next week there will be lightning bolts flying around in that engine compartment! I can't see throwing money into old parts when there's so much good new stuff on the market today. I'll let you know how I make out.