Mercruiser has no spark but cranks good.

[Don S]

Re: Mercruiser has no spark but cranks good.

Yea, you need a new switch. It's a boat and switches corrode and die.

 

[WSR]

Re: Mercruiser has no spark but cranks good.

On my way to get one...be back with the report tomorrow. This is a part I dont mind thowing $ at since its so small. I might return the coil if it works. Thank you so much for your help you truly are the "DON" of boat know how. Should of posted two weeks ago instead of following threads all day. At least I earned my engineering degree while trouble shooting everything from the alternator,tach,neautral saftey,coil, distributor...you name it. I got every inch of that thing now. Blessing in desigue?

 

[chiefalen]

Re: Mercruiser has no spark but cranks good.

You could have just pulled the 2 wires off it and put them together to confirm the switch was bad.

And start the boat.

Than go get the switch. IF YOU WANTED TO KEEP THAT SWITCH.

 

[WSR]

Re: Mercruiser has no spark but cranks good.

I pulled the two wires off to bypass the switch and she got voltage and fired right up on the hose....twice.Like a car!I went and got a new switch.Gotta be up to code with homeland around here.
Before I put it in I went for a test run...Bad day.
Off trailer great.Docked great..Cruzin for about 15 minutes all temp and tach perfect and a passenger lost a hat, made a u turn came up slow on the hat in neutral and it stalled.
It never started again.
Floating, I confirmed the voltage at the coil.It was cranking like a champ.I had a spark plug tester it lit up.Checked my splice ect...
So now I am getting a spark, its cranking, I see fuel in the bowl.
But still wont start.Thank GOD for a great couple coming into port from Seattle WA in route to the Caribbean (great karma) in a beautiful sail boat named Lilly.
Now it wont even start on the hose back at home...but at least I made it home.

 

[98LSWON]

Re: Mercruiser has no spark but cranks good.

Off trailer great.Docked great..Cruzin for about 15 minutes all temp and tach perfect and a passenger lost a hat, made a u turn came up slow on the hat in neutral and it stalled.
It never started again.

Been there....done that. Glad you made it back OK.

http://www-alt.mercurymarine.com/mne...anl/7/7cov.pdf

Download this, it has a very simple and helpful troubleshooting section on the Thundrbolt IV.

 

[WSR]

Re: Mercruiser has no spark but cranks good.

I cant view it. But is it the flow chart? I also have the SELOC manual, and some of the clymer and factory Mercruiser stuff I found on the web.

 

[Haut Medoc]

Re: Mercruiser has no spark but cranks good.

I cant view it. But is it the flow chart? I also have the SELOC manual, and some of the clymer and factory Mercruiser stuff I found on the web.

Put the Seloc & Clymer's in the outhouse where they belong & download the OEM manual for your engine......
http://forums.iboats.com/showthread.php?t=251571
That flow chart should be in there somewhere....
However, the fact that it quit after making a hard turn suggests a fuel problem to me.....
When was the last time you changed the water separating fuel filter?
By all means go through the flow chart for the ignition, but it sounds like a fuel issue to me......
Do you get a good stream of fuel when you pump the throttle?.....
You could try pouring a little gas right into the carb & se if it will fire at all......

 

[Don S]

Re: Mercruiser has no spark but cranks good.

The link 98 posted was for the OEM service manual. But he just copied and pasted the link which only gets part of the link. That's why it doesn't work. Here it is again, and it does work. Note it's big, 587 MB in size.

Service Manual #7 GM V6 1983 - 1993
http://www-alt.mercurymarine.com/mnetdata/SERVICE/CRUISER/Servmanl/7/7cov.pdf

I'm thinking it may have flooded (with gas). Did you try to open the throttle wide open and crank it. That is how you clear a flood condition.

 

[WSR]

Re: Mercruiser has no spark but cranks good.

Don Thanks for the link.
I do get a good stream of fuel, and I did try to clear it wide open a number of times, and let it sit for over 30 min.(Plenty of time on the tow in).
Same thing back home on the hose.

 

[WSR]

Re: Mercruiser has no spark but cranks good.

I smell gas. I see alot of gas in the bowl. I feel like its not making it to the intake manafold. Does that make sense?

 

[WSR]

Re: Mercruiser has no spark but cranks good.

As far as the filter goes in the manual it says "if so equipped". Could I not have one? I put in a new fuel pump at the beginning of the summer and looked for it then.

 

[WSR]

Re: Mercruiser has no spark but cranks good.

Do I need to start a new thread?

 

[Don S]

Re: Mercruiser has no spark but cranks good.

Do you have spark at all the spark plugs? I mean good blue spark, not some weak yellow or orange colored spark.

 

[Haut Medoc]

Re: Mercruiser has no spark but cranks good.

As far as the filter goes in the manual it says "if so equipped". Could I not have one? I put in a new fuel pump at the beginning of the summer and looked for it then.

Well I would think they would be standard on a 4.3 but....
Follow the fuel line, if you have one you'll find it....

Do I need to start a new thread?
NO....

 

[imported_TheMan]

Re: Mercruiser has no spark but cranks good.

It looks like an oil filter attached to your gas line. It will be tough to miss since they are designed to be changed and thereby are placed in accessible areas..

 

[Don S]

Re: Mercruiser has no spark but cranks good.

The 89 and 90 engines didn't have a spin on fuel filter water sepeerator mounted on the engine. 91-92 had the inline filter, but was not a water seperator. In 93 they started installing a fuel filter/water seperator on the engine.
The problem is, he stated that he is getting gas. Or so I thought after reading this. Maybe that good stream of fuel isn't from inside the carb.

I do get a good stream of fuel, and I did try to clear it wide open a number of times, and let it sit for over 30 min.(Plenty of time on the tow in).

but now after re-reading some of his posts like the one below, I'm not to sure.

I smell gas. I see alot of gas in the bowl. I feel like its not making it to the intake manafold.

A very simple test will be to pour a few tablespoons of fuel into the carb and see if it will start.
Your problem could be as simple as a failed accelerator pump in the carb.

 

[Haut Medoc]

Re: Mercruiser has no spark but cranks good.

Put the Seloc & Clymer's in the outhouse where they belong & download the OEM manual for your engine......
http://forums.iboats.com/showthread.php?t=251571
That flow chart should be in there somewhere....
However, the fact that it quit after making a hard turn suggests a fuel problem to me.....
When was the last time you changed the water separating fuel filter?
By all means go through the flow chart for the ignition, but it sounds like a fuel issue to me......
Do you get a good stream of fuel when you pump the throttle?.....
You could try pouring a little gas right into the carb & see if it will fire at all......

I do like the simple tests first......

 

[Don S]

Re: Mercruiser has no spark but cranks good.

Missed that,You posted that while I was typing a previous reply.

 

[WSR]

Re: Mercruiser has no spark but cranks good.

I was flooded. Started right up last night after work while on the hose then a couple of times in the tub. It must of been real bad because I tried to clear it to the point I thought I was gonna fry my starter.
Weird thing is, over the summer pulling the kids on the tube I made many turn like the one that did me in. No problems.
BAD GAS? I could imagine flooded with bad gas is even worse?
I definitely do not have the separator, its a 90. Can I install one with the current fuel pump I have?
Any reason to keep the new coil? I put on the old one and she started. I am gonna put a tune up kit on it next week...is there any way to test it?

 

[Haut Medoc]

Re: Mercruiser has no spark but cranks good.

I was flooded. Started right up last night after work while on the hose then a couple of times in the tub. It must of been real bad because I tried to clear it to the point I thought I was gonna fry my starter.
Weird thing is, over the summer pulling the kids on the tube I made many turn like the one that did me in. No problems.
BAD GAS? I could imagine flooded with bad gas is even worse?
I definitely do not have the separator, its a 90. Can I install one with the current fuel pump I have?
You probably have some water in your tank....
I would absoloutely install a water separator, & it will not affect your pump at all, other than keeping any crap out of it & the carb.....
I would completely drain the gas tank....
Get a clear 5 gallon jug & let it settle....
You will see the good gas separate from unwanted stuff, use the good stuff in your car & set the crap aside for later disposal.....
Once you have the tank drained, add the separator.....
If you are not going to do the separator right away, you can run the engine on an external tank with fresh gas.....
Any reason to keep the new coil? I put on the old one and she started. I am gonna put a tune up kit on it next week...is there any way to test it?

Keep the coil as a replacement, if you all ready used it, they might not take it back......