2002 350 mag mpi towsport ser# OM310754 no spark

[lilhuff]

OK I have finally had time to get back to the boat issue. I have since replaced the ECM, fuel pumps, igniton coil and controller, plugs, checked compression great in 7 cylinders and a little low in 1 but still within 30% of highest which is 190psi.
I borrowed a laptop and mercruiser program from one of the local marinas and here is what the code faults are:
16 MAP Sensor circuit low
94 Pitot Pressure circuit low
85 Oil pressure circuit low
75 Fuel level 1 circuit high
121 TPS 1 circuit low
130 trim sensor circuit high
The diagnostics on the computer reads 40psi for oil pressure with the key in the on position. I still can't get it to fire. I ran down all of the voltage checks and continuity checks in the 36 ECM 555 manual and everything looks OK. I had voltage and continuity everywhere. Does anyone know what step 15 is on trouble shooting chart A-5? I had continuity between connector C and B-10 and it says to go to step15 which is not in the manual? If it is replace the CPS I replaced it and I still can't get a spark out of the ignition wire from the coil to distributor. I am taking a lead from the post and taking it to ground and get nothing.
Any ideas would be greatly appreciated.

 

[Don S]

Re: 2002 350 mag mpi towsport ser# 310754 no spark

Re: 2002 350 mag mpi towsport ser# 310754 no spark

You missed the letter in front of your serial number.

Basically, with no spark, all those circuit low and high and counts means nothing

 

[lilhuff]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

Sorry it is OM310754. Thanks

 

[lilhuff]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

I forgot to mention that I also checked to make sure the tach was not grounded out. That gauge cluster does not work but I removed the hot leg and nothing changed. The neutral safety switch and kill switch both work as I would expect. The motor does not crank over when is in gear or the safety lanyard is not connected.

 

[Don S]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

I normally throw away old manuals when they get updated, I never got rid of the old 36 manual. Look what they forgot to put in from the 2002 version,

 

[Don S]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

I assume you started from chart one and worked your way to the missing 15 and everything passed up to that point, correct?

 

[lilhuff]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

Yes I started at the beginning of the trouble shooting section.

 

[Don S]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

Did you see reply #5 ?

 

[lilhuff]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

Yes I did thank you very much! Thumbing through the manual now looking for the normal sensor resistance chart and can't seem to find it. I will go ahead and check the resistance and make sure the new CPS is in spec. I won't check the old one cause it will probably be in spec and that definitely means I have gone down the path of throwing parts at it and I desperately try to stay away from doing that.

What would you think the next step might be if the cps checks out?

Again thank you for the help I greatly appreciate it.

 

[Don S]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

Give me a few minutes, and I will upload the old manual. Hard to say what else is in it that you could use. It is the 2002 version.

 

[Don S]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

Well, that uploaded pretty quick. Here's the old one. http://www.4shared.com/office/UxMeL7wK/36_555_old.html?

 

[lilhuff]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

Thanks Don S. I have it saved on my pc. The manual I am using is dated December 2006. I will go through it with the 2002 manual this weekend and see what happens and follow up. Again thank you for your help and quick responses. If you have any other ideas I would appreciate any help.

Thanks again,
Lilhuff

 

[lilhuff]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

The CPS seems to be OK and the visual / physical inspection looks OK. Is it possible that the ECM is working on everything except firing the the coil? Is there something in the dash wiring harness that could stop the engine from firing the ignition coil? I have checked the tach but am not comfortable with the method used. I disconnected the power lead and cleaned the contacts but that gauge cluster does not seem to be working. Wouldn't the tach and oil pressure blip on the key being turned to the on position. I see no signs of life on the gauge cluster like I do with the others.
Any suggestions would be greatly appreciated.
Thanks,
Lilhuff

 

[Don S]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

When you first turn the key to the run position, (not start) does the fuel pump run for 2 seconds and shut off?

 

[lilhuff]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

Yes the fuels pumps come on for a few seconds when the key is in the on position and shut off. This started when we replaced the ECM with a used one for the same motor from a 2005 but for Bravo drive. We cleared the codes on the ECM and the ones above are from our motor. The ECM seems to communicate with the computer fine with the exception of throwing the codes above. From information from this forum and what I have read the codes should not stop it from firing.
Thank you your replies.

 

[Don S]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

This started when we replaced the ECM with a used one for the same motor from a 2005 but for Bravo drive.

I think it's obvious where your problem is now. Why did you replace the ECM? Put the original back on and see if you have spark.

 

[lilhuff]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

The ECM had water in it and was not working. The back half of the boat went under in a flash storm and the bilge pump did not come on. We have replaced most of the components, starter, both fuel pumps, coil and controller, CPS and both relays. Do you think the ECM is looking for a sensor that is not on an inboard? I am out of options at the moment and really have been concerned about buying another ECM due to the expense but would be more than willing to spend the money if it fixes the problem. I have been told that these ecm's are pretty much on or off and have been fairly bullet proof. I really wish I new someone close that had a comparable boat that we could test the ECM in our boat. Is there away to test the signal from the ECM to the coil controller while cranking the motor? Just to see if it is in the ECM and not something in the dash?

 

[Don S]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

At this point, I have no clue. The wiring harness may even go to different places from the MCM (sterndrive) version to the MIE (inboard) version your engine is. Then there is year differences. Merc also had different part numbers for the different ECM's, so you know there has to be differences somewhere. Plus they have different wiring harnesses between 2002 and 2005 let alone just MCM vs. MIE.
Perhaps your ECM can be re-programmed.

 

[lilhuff]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

In your experience is there anything from the dash that would stop it from firing. The neutral safety switch is operating and the only other thing I could think of that might stop it from firing is the tach. I think at this point unless you uave an idea on the dash I need to take into a mercruiser shop and have them go through it.

 

[Don S]

Re: 2002 350 mag mpi towsport ser# OM310754 no spark

In your experience is there anything from the dash that would stop it from firing.

No, it puts power to the engines purple wire, and since the fuel pumps run, that part is working.
The neutral safety switch just keeps the starter from cranking the motor.
The kill switch would also prevent the fuel pumps from working.

If you do take it in, tell them about the used and different ECM.