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TBroccoli
08-02-2010, 12:52 PM
1996 22 classic with 454 magnum. Wakeboarding all morning. Starting and stopping the engine. Tried to start and it would turn over but not start. At first I thought is needed fuel. Choked it and realized it was getting plenty of fuel. All it does is turn over and over and over. I took a spark plug wire off and attached a spare plug. Grounded it and turned the motor over. No spark. I pulled the coil wire from the distributer and checked and got no spark. What do you think it could be? Bad module in the distributer? Bad coil? How do I test these?

gcarter
08-02-2010, 01:01 PM
Lanyard and safety kill switch ???

If it is, don't feel bad, it's not the first time that's happened.

mrfixxall
08-02-2010, 01:36 PM
check the ignition,purple wire under dash for power if you have it then go to the coil.

first check the coil for power(purple wire) if their is power remove all the wires on the - side of the coil,remove the coil wore and hold it towards a ground,momentary ground the - side of the coil,if it sparks at the coul wire then its good if not then replace it...if the coil does spark then move to the hall effect in the distributor,, sorry i have a test one and its faster to replace it then going through all the bs of testing it..

TBroccoli
08-02-2010, 01:37 PM
Checked. No, but I wish it was. That just happened to (new to boating) neighbor. He realized it after being towed in.

MOP
08-02-2010, 05:10 PM
Like fix said check for juice at the coil, also go over the connections back there especially the ground under the distributor base. If all looks good first borrow a coil to see if that fixes things, the module would be my next suspect then the pack. The packs seem to be the most durable.

Phil

TBroccoli
08-02-2010, 08:36 PM
Got power on purple wire under dash. Got power at purple wire on coil. Got spark from coil. Tested it with dad's old coil tester. Where do the two wires from the negative side of the coil go? Got no power on either end of the wht/red lead from the distributor. What is attached to the back side of the distributor? Is it the ignition module harness? Could that or the ignition module be bad? With a good coil, what would cause it to not send a spark?

gcarter
08-02-2010, 08:42 PM
This is where a manual comes in really handy.
I was trying to answer Chachi's question this morning and went right by a perfectly good schematic for the T Bolt igniton system.
It's sitting on my desk at my office.

But if YOU had one............

MOP
08-02-2010, 08:54 PM
Anyone close by that you could try another pack, the pack is plug and play and would rule it in or out as the cause. Could still be the module under the cap! Phil

handfulz28
08-02-2010, 09:18 PM
Coil wire
Cap/rotor
pickup coil
ignition module
spark control

I went through a bunch of this diagnosis a week ago on an old truck ('93 305 TBI). Wouldn't start but getting spark at the plug. Coil ohm'd OK, pickup coil ohm'd OK and supposedly the ignition module (back of distributor) tested OK at the parts store. Ended up just putting a whole new distributor in and fired right up.

Hijack on....Since I started dealing with these older TBIs, I noticed they use an Electronic Spark Controller (ESC) that looks mighty similar to the Merc Thunderbolt ignition module. Been wondering if there's a very different spark curve...hijack off

TBroccoli
08-02-2010, 09:33 PM
Anyone close by that you could try another pack, the pack is plug and play and would rule it in or out as the cause. Could still be the module under the cap! Phil

Is the pack attached to the back of the distributor?

TBroccoli
08-02-2010, 09:34 PM
This is where a manual comes in really handy.
I was trying to answer Chachi's question this morning and went right by a perfectly good schematic for the T Bolt igniton system.
It's sitting on my desk at my office.

But if YOU had one............


I wish I had a manual. how do I know I have the T Bolt ignition?

gcarter
08-02-2010, 09:50 PM
Thunderbolt ignition is the standard for Merc engines. Generally they are VERY dependable.
I hope you are successful in diagnosing your problem.
MOP knows his stuff, he always has good info.

mrfixxall
08-02-2010, 10:03 PM
I wish I had a manual. how do I know I have the T Bolt ignition?


if you have a thunderbolt ignition their should be a module mounted to the starboard side exhaust riser,looks like the one in pic 1

replace the pick up (hall effect)in the distributor first pic 2,,they just go out,their cheep around 60 bux..just pull the rotor and theirs 2 phillip screws and its out..

the modules are 325.00 - 500.00 new but most of the older ones are NLA..

craigdskilling
08-02-2010, 10:11 PM
I had the same problem.I found a fuse was blown under the dash.IT would turn over all day to.

gcarter
08-03-2010, 06:58 PM
the modules are 325.00 - 500.00 new but most of the older ones are NLA..

There's a lot available on eBay. The prices are all over the place. I've bought new ones for $150.00.
Here's a list of the ones available. Your existing module has markings on it identifying it.

http://www.donzi.net/forums/attachment.php?attachmentid=56592&stc=1&d=1275797165

DonziJon
08-03-2010, 07:13 PM
if you have a thunderbolt ignition their should be a module mounted to the starboard side exhaust riser,looks like the one in pic 1

.

Mine is on the PORT side....that's the RIGHT side as you face AFT. Just Sayin.

mrfixxall
08-03-2010, 07:19 PM
Mine is on the PORT side....that's the RIGHT side as you face AFT. Just Sayin.


your rite! :bonk:

TBroccoli
08-03-2010, 08:34 PM
Guys, thanks for all the help. I will have time tomorrow to dig into it again. I'll get a hall effect and try that first. What fuse is under the dash?

TBroccoli
08-04-2010, 05:53 PM
I think I have a thunderbolt V. Is there a way to test the knock control module? Or the Ignition control module? Could something have come loose to prevent the coil from creating a spark?

Cuda
08-04-2010, 06:17 PM
Pull a plug, leave it on the wire, and hold the sparkplug against the block to ground it. You should see fire. I have never found a bad coil as many times I convinced myself it HAD to the the coil. I've got a bunch if coils to proved it.

TBroccoli
08-04-2010, 07:52 PM
No fuse found under the dash. Did realise the little "nipples" on the dash have what I think are little breakers behind them. They all seem not tripped. I found on another site a guy stating his ignition control module on his thunderbolt V ignition was full of water and caused the engine to cut off and not start again. Now, my ICM is on the back of the distributor and directly under the rear of the hatch. My kid climbed up the outdrive dripping wet right before I couldn't restart the engine. Could he be on to something? Has anyone else heard of water damaging the ICM?

If the coil is good (tested good), what would cause it not to send a spark to the distributor when the key is turned and the engine turning over????????????

MOP
08-04-2010, 08:56 PM
The IV and V systems use the module in the distributor to trigger the pack, the pack in turn signals the coil to fire. As the RPM climbs the pack rolls the timing up, if possible borrow a pack it is plug & play and cannot be harmed. If it fires off buy a pack if it does not change out the module in the distributor. The two work hand in hand!!!!

Cuda
08-04-2010, 09:52 PM
Do you have spark at the plugs?

RickSE
08-05-2010, 10:26 AM
Check the wiring to all your solenoids and relays. I had a similar situation happen on my 500EFI that ended up being a loose wire on a solenoid. I seem to remember that mine was related to the kill switch circuit and there was a solenoid at the back of the motor that was the problem. Took us a long time to find it.:frown:

TBroccoli
08-05-2010, 04:28 PM
Check the wiring to all your solenoids and relays. I had a similar situation happen on my 500EFI that ended up being a loose wire on a solenoid. I seem to remember that mine was related to the kill switch circuit and there was a solenoid at the back of the motor that was the problem. Took us a long time to find it.:frown:

Rick,I thought I ruled out the kill switch, but maybe not. With the key in run position and kill switch in run position i have 12v to the coil. Activating kill switch loses 12v at the coil. Does that mean the kill switch is working correctly?

CUDA, No spark at plugs.

More troubleshooting this weekend. Busy today and tomorrow.

Cuda
08-05-2010, 05:48 PM
Rick,I thought I ruled out the kill switch, but maybe not. With the key in run position and kill switch in run position i have 12v to the coil. Activating kill switch loses 12v at the coil. Does that mean the kill switch is working correctly?
CUDA, No spark at plugs.
More troubleshooting this weekend. Busy today and tomorrow.
I bet it is the pick up coil in the distributor then. I had to replace one of mine in the Formula, so I did both. It was an easy inexpensive job.

The kill switch grounds the ignition on some models, so I'd say it's doing the job.

mrfixxall
08-05-2010, 06:39 PM
Is your engine fuel injected??

RickSE
08-05-2010, 07:04 PM
...Does that mean the kill switch is working correctly?

Sounds like this circuit is OK then.

gcarter
08-05-2010, 07:12 PM
You know, these anecdotal crap shoots could go on for days until Tom just lucked onto the right fix.......

Or you could go to your nearest Merc dealer and buy a manual for your year (or years), even a Clyner for $25.00.
Check it out.

Cuda
08-05-2010, 07:15 PM
You know, these anecdotal crap shoots could go on for days until Tom just lucked onto the right fix.......

Or you could go to your nearest Merc dealer and buy a manual for your year (or years), even a Clyner for $25.00.
Check it out.
Can he just open the hatch and toss a manual in there? I'm all for that.

DonziJon
08-05-2010, 08:06 PM
Manuals just make things way too complicated....and you have to actually read them. I would come here first....and maybe get lucky. :yes: ................... Just kidding....

Cuda
08-05-2010, 09:09 PM
Manuals just make things way too complicated....and you have to actually read them. I would come here first....and maybe get lucky. :yes: ................... Just kidding....
Yeah those manuals usually want you to do some of that pesky testing.

TBroccoli
08-07-2010, 11:35 AM
Got the hint. I will buy a manual. I thank thoughs who spent some time and offered insiteful help.

gcarter
08-07-2010, 01:18 PM
Tom, if my manual would have been of any help, I would have scanned pages and posted them, but your system is a generation later than mine.
So the best thing for you is to get your own.

Cuda
08-07-2010, 03:33 PM
You can just leave the knock sensor loose. It's the only difference between a TB IV and a TBV.

TBroccoli
08-07-2010, 03:54 PM
Got a manual. Step 5 of my test is to disconnect the red/white wirefrom the distr. to the ICM. Test for 12v from the wht/grn on the ICM. I got nothing. Manual states to replace module. If I got 12v I would then test the sensor in the distr. So it looks as though i at least need the ICM. Once replaced I will be able to test the sensor.

DonziJon
08-07-2010, 07:34 PM
Got a manual. Step 5 of my test is to disconnect the red/white wirefrom the distr. to the ICM. Test for 12v from the wht/grn on the ICM. I got nothing. Manual states to replace module. If I got 12v I would then test the sensor in the distr. So it looks as though i at least need the ICM. Once replaced I will be able to test the sensor.

I always get confused by all this tecky talk...I don't feel like reading the Manual ....SO...what's an ICM..? If I don't have one......do I need to get one..? :nilly: ................:)

TBroccoli
08-07-2010, 08:16 PM
ICM = ignition control module. Mine is full of water. I need a new one. Looks like they run about $300 - $400.

CUDA The manual doesn't mention that the Knock modue would affect my issue. Am i missing something?

gcarter
08-07-2010, 08:55 PM
I just did a search on eBay and found 54 of them starting @ about $50.00.
Don't hesitate to buy a used one, they're usually just fine.

Cuda
08-07-2010, 11:15 PM
ICM = ignition control module. Mine is full of water. I need a new one. Looks like they run about $300 - $400.
CUDA The manual doesn't mention that the Knock modue would affect my issue. Am i missing something?
No, it won't effect it at all.

handfulz28
08-08-2010, 11:25 AM
ICM=Ignition Control Module

Are you talking about the part on the distributor, or the part attached to the manifold?


Now, my ICM is on the back of the distributor and directly under the rear of the hatch.

Went back and re-read....you can find this part for under $100 brand new. Check Ebay or call your local supplier. I'm willing to bet you could also get away with the street version, if you really had to ($25-45).

The BIG money part, also referred to as an Ignition Control Module, is more accurately a Spark Advance module, or Electronic Spark Control (ESC on road-going vehicles).

Cuda
08-08-2010, 12:37 PM
My guess would be the pick up sensor under the distributor cap. It doesn't cost much and it won't hurt it. I think I ordered it from Dollar Marine and had it the next day.

TBroccoli
08-09-2010, 12:18 PM
I just did a search on eBay and found 54 of them starting @ about $50.00.
Don't hesitate to buy a used one, they're usually just fine.

What did you type in as your search?

TBroccoli
08-09-2010, 12:20 PM
I found on another site a guy stating his ignition control module on his thunderbolt V ignition was full of water and caused the engine to cut off and not start again. Could he be on to something? Has anyone else heard of water damaging the ICM?

Mine is full of water. CAn it be dried out?

gcarter
08-09-2010, 02:45 PM
What did you type in as your search?

Mercruiser Ignition Module

TBroccoli
08-09-2010, 10:16 PM
Has the Thunderbolt V ignition control module been upgraded? The part number on mine is 806745 5. I've been told that a part number exists that is called ICM kit. It is 806745A01. The plug is different but it comes with a pig tail to mate with existing harness???? No one can show me a picture of the kit.

gcarter
08-09-2010, 10:37 PM
Tom, due to the similarity of the # and its function, it's probably just as it says.
On the Serious Offshore forum, there's a guy, Mobilemercman, that can probably answer your question.

mrfixxall
08-09-2010, 10:57 PM
Mine is full of water. CAn it be dried out?

you can try to,take a ice pic and heat the tip until its glowing red..Then poke a hole in the corner on the face of the module,drain the water out and put it in the sun for a few hours and try it..

TBroccoli
08-17-2010, 06:59 PM
Finally found a supplier with the correct module. had it overnighted from michigan. Put it in, tested good, and fired up! i was on the water within an hour.

Thanks for all the help. Got to admit i was pretty upset with all the "get a manual" comments, but it is the best money spent this season. Thanks for the guidance and all the help.

On to the next problem.

gcarter
08-17-2010, 09:10 PM
Thanks for all the help. Got to admit i was pretty upset with all the "get a manual" comments, but it is the best money spent this season.

Tom, this may come under the "Tough Love" category.....
But I wish more folks would come to the same understanding.
It seems so many people want to "go on the cheap" when it comes to their boat maintenance.
Manuals cost less than $30.00 and can literally save a handy person thousands of dollars.

Cuda
08-18-2010, 12:31 AM
I've never yet had a maual fix a damn thing, on the other hand, if I can't fix it, it ain't broke.

Tidbart
08-18-2010, 07:46 AM
I've never yet had a manual fix a damn thing, on the other hand, if I can't fix it, it ain't broke.

I've never had a textbook that could teach, but aren't you taking classes?:wink::bonk:

Cuda
08-18-2010, 02:08 PM
I've never had a textbook that could teach, but aren't you taking classes?:wink::bonk:
Not taking classes this semester. I'm about to move back to Pinellas to get my Bachelors in math.

I can read a voltmeter and understand the principles of a four stroke engine. I have a picture of me helping my dad rebuid an English Ford at about 5 years old, and mom says she has a picture of me less than a year old when my dad was rebuilding a scooter in the Phillipines and I have grease all over me. Mom says I got ahold of the chain. :)

Tidbart
08-18-2010, 02:24 PM
Good for you. Hope you do well.

B