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View Full Version : How do I check the spark sequence?


MC Old Skool
06-04-2008, 05:29 PM
Alright I'm a newbie here but I would like to start off by thanking all of you. I have read your threads in the past and they have definitely helped me solve many of the problems I have encountered since purchasing my boat 4 years ago and I truly appreciate all of the help.

My issue at the moment is that my 1990 Prostar with a Ford Indmar 351 needs a bit more help than I can provide it. My stubborn nature and pocket book have kept me from taking it in for service. I also prefer to do the work myself.

I did a driveway test before I took it out his season and everything sounded great. I towed it out to the river and it started up without hesitation but every time I went to back down it stalled. I pulled the boat out of the water and was able to put it into drive and run it quickly just to make sure the prop wasnít seized. It seemed to be an only under load issue.

I purchased a remanufactured holley marine carburetor 4160 before the trip and immediately pointed fingers at the carb guy thinking that was the issue... After returning it, the bench testing begged to differ.

So I went through replacing anything it could have been the fuel pump, oil water separator, checked the fuel tank for clogged or collapsed hoses and fittings, also checked the screen, replaced the impeller, and put a new distributor and rotor on, as well as a fresh set of plugs. I also bypassed the ignition coil relay since my ignition is electronic. FYI my starter is new last season as well and I am definitely getting juice.

Once I put all of the new parts on and cranked it over it started once sounding strong and died out. Now I canít even get it to start???

I think I may have the firing sequence wrong, a loose ground or the timing is off.... Any other suggestion?

If anyone can help provide me or point me in the right direction to find some visual guides or instructions on how to set the timing and firing order for my boat I would greatly appreciate it.

I have searched the net far and wide but I really could use some help from my fellow MC members wrapping my head around this.

Thanks,
Jessee

Laurel_Lake_Skier
06-04-2008, 09:44 PM
So I went through replacing anything it could have been the fuel pump,........, and put a new distributor and rotor on, as well as a fresh set of plugs. I also bypassed the ignition coil relay since my ignition is electronic. I think I may have the firing sequence wrong, a loose ground or the timing is off.... Any other suggestion?

Did you replace the entire distributor or just the cap? If you pulled the old distributor, you need to get it aligned correctly before you go any further with the firing order and timing. If you just put on a new cap and rotor and need a firing order, it is 1-3-7-2-6-5-4-8 number one cylinder is front left looking from front of engine and distributor spins counterclockwise. You'll need a timing light to check ignition timing, 10ļ BTDC @ 600rpm. Not sure what you mean by ignition coil relay.....possibly the ballast resistor, but yes a loose wire or cut insulation grounding out could disable your ignition. Check for spark at the wire coming out of the coil to help narrow down what might be happening.

sk8salomon
06-05-2008, 05:48 AM
if your firing order is messed up the engine shouldn't run at all. i'd start with distributor alignment 1st.

TMCNo1
06-05-2008, 06:26 AM
if your firing order is messed up the engine shouldn't run at all. i'd start with distributor alignment 1st.

It would run unless all or most were wrong, but you would have a lot of backfiring, been there. I got a bad module in my original conversiuon kit, and the engine would run too, but it backfired real bad too, till we put in a new replacement module and it ran perfect.

MC Old Skool
06-05-2008, 11:35 AM
I know what I will be doing this weekend thanks for the advice :)