Electrical Troubleshooting Help Needed

hd2002hd

Member
Jul 20, 2010
457
St. Louis
Boat Info
1996-Sea Ray 215 Express Cruiser/1996-Sea Ray 330 Sundancer/1998-Sea Ray 400 Sundancer/1996-Sea Rayd
Engines
5.7 Mercruiser/454's/454's w/V drive/120HP
I have a 1998 400 Sea Ray w/EFI. I fired up last night to go to dinner and the starboard engine did not immediately fire off as it normally does. I tried it again and it cranked for a few seconds and started. We proceeded to dinner without any further incident. However, when we went down to the dock after eating, the starboard engine again would not start. It would crank just fine, but never fire. After several minutes of light troubleshooting and no luck, we proceeded back to the marina on port engine only. Luckily it was a very calm night and we were able to get in the slip with little issue. Today, I tore into the issue deeper. First I checked the fuel pump. It came on and pressured up just fine. I then used the multi meter to test so ignition points to make sure there was power where I thought it should be and there was. The marina mechanics were busy, but I was able to pick their brains a bit. The first thing they had me try was to pull a plug and see if it fired and it did not. They had a spare coil they said was good that they let me borrow and I tried it and nothing. They recommended changing out the module inside the distributor. I pulled the cap and changed out the module and still nothing. I did note that there was a bit of corrosion inside the distributor on the contact points as well as the rotor. I cleaned this up as well. This is where I am now. The motor cranks over just fine, just no spark in the plugs. Does anyone have any other suggestions of what to look, check or replace. Oh, on another note not related to the issue directly. While traveling back slowly on the port, as I pulled into the cove I could see a boat over near the breakwall travelling from my port to starboard maybe 150 yards away. He turned his lights off so I assumed a water patrol. I was diligently looking for the boat but I could not see with the darkness (cloudy). As I pointed to the opening into the marine the mystery boats flipped on his nav lights and he was maybe 20' off my bow travel at an angle, but still port to starboard. It was performance boat. No idea why he did that, but we were close to making some contact. Scared the crap out of me. Trying to maneuver to avoid a collision with one engine was not fun.
 
Might try taking the 811637001 ignition trigger module out of the running motor's distributor and installing in the other.
If you saw corrosion then quite possibly the pickup coil which is in the distributor is compromised. Try using the pickup from the other engine also.
 
So, I did buy a new module that goes inside the distributor and bolts to the distributor plate and still no luck. A mechanic is telling me it is the round thing (maybe the pickup???) that the rotor bug snaps on to. So they are saying I need to replace the whole distributor. Thoughts?
 
Swap the distributor from one motor to the other and see what happens.
 
I had similar issues with a 5.7L engine that was carb'd on a 1998 boat....it was difficult to diagnose because the problem was intermittent.....finally the engine died and would not start....it ended up being the ignition control module for the Thunderbolt V ignition system....instead of paying almost $600 for a new module from Mercruiser I switched the entire ignition system (including distributor) over to a marine Delco EST system for around $400....worked perfectly....no starting issue for as long as I owned the boat after the swap.....

cliff
 
Looks like it is coming down to the distributor. I am not 100% confident in this, but the mechanic thinks so. I am wondering if there are any other switches that would prevent firing? The mechanic isn't sure if the neutral safety switch only prevents cranking or if it affects firing or if there is another switch that may prevent firing.
 
It was the distributor. I didn't have enough confidence in my ability to pull a distributor out and stab in the other engine without creating numerous other issues. Especially a timing issue. I would like to change the port distributor out at some point if anyone has good advice on how to do it without screwing more things up?
 
I`m assuming this is a throttle body motor and not a fuel injected motor.
The Safety Lanyard will kill the ign but not the cranking
 
I`m assuming this is a throttle body motor and not a fuel injected motor.
The Safety Lanyard will kill the ign but not the cranking

Large inboard boat don't have safety lanyards.
 
Ok then, look to see if the engine harness was cut and reconnected using a connector block. Corrosion there could be the problem.
 
It is fuel injected. It started and ran fine. The timing was adjusted and off we went. I ran it a couple of weekends before I noticed the engine that had the new distributor wouldn't run up to the RPM's I expected. I typically only run about 3200 rpm. When I bought the boat in 2012, both engines ran about 4300 rpm WOT. Now, the engine with the new distributor only runs about 3200 rpm WOT while the other one runs about 3900 rpm WOT. I have never ran either of them WOT since my initial test run. So, what would prevent the engine with the new distributor from running on up? Is it possible the wrong distributor is in it or would it not run at all in that case?
 
It is fuel injected. It started and ran fine. The timing was adjusted and off we went. I ran it a couple of weekends before I noticed the engine that had the new distributor wouldn't run up to the RPM's I expected. I typically only run about 3200 rpm. When I bought the boat in 2012, both engines ran about 4300 rpm WOT. Now, the engine with the new distributor only runs about 3200 rpm WOT while the other one runs about 3900 rpm WOT. I have never ran either of them WOT since my initial test run. So, what would prevent the engine with the new distributor from running on up? Is it possible the wrong distributor is in it or would it not run at all in that case?
did you re-time the motor after the swap? This has to be done. If you don't have correct advance the motor will not reach higher rpms.
 
did you re-time the motor after the swap? This has to be done. If you don't have correct advance the motor will not reach higher rpms.

Well, the guy that installed the distributor did put a timing light on it. However, I’m not sure he timed it correctly. I couldn’t see the timing marks or anything since the engines are rear facing, but it seemed he was really trying to get to idle at 650 rpm’s more than anything. I don’t know that much about the timing. I assume you just line the marks up on the crank with the light by adjusting the distributor until they line up? I would assume the right way is to get the marks lined up and then adjust the idle however you adjust the idle on a fuel injected engine?
 
Well, the guy that installed the distributor did put a timing light on it. However, I’m not sure he timed it correctly. I couldn’t see the timing marks or anything since the engines are rear facing, but it seemed he was really trying to get to idle at 650 rpm’s more than anything. I don’t know that much about the timing. I assume you just line the marks up on the crank with the light by adjusting the distributor until they line up? I would assume the right way is to get the marks lined up and then adjust the idle however you adjust the idle on a fuel injected engine?

Well that is part of it, you also have to put the motor in "service mode" there is a procedure and tools for doing this. You can't just hook up a basic timing light and set it to the marks - if you do the advance will be wrong. Even my carbureted engine has to be be put in "base timing mode" to properly set the timing. I would start with verifying the timing and advance is set properly - an improperly timed motor would exhibit the symptoms you are seeing. Actually, if the other motor is only reaching 4300rpm it has something going on also, really should be in the 4400-4800 range, should be a sticker somewhere on the motor with the WOT RPM range - definitely should be more than 4300.
 
Well that is part of it, you also have to put the motor in "service mode" there is a procedure and tools for doing this. You can't just hook up a basic timing light and set it to the marks - if you do the advance will be wrong. Even my carbureted engine has to be be put in "base timing mode" to properly set the timing. I would start with verifying the timing and advance is set properly - an improperly timed motor would exhibit the symptoms you are seeing. Actually, if the other motor is only reaching 4300rpm it has something going on also, really should be in the 4400-4800 range, should be a sticker somewhere on the motor with the WOT RPM range - definitely should be more than 4300.

What is the process to put it in “base timing mode”?
 
What engines do you have?

If they are the 7.4L (454cid) or 8.2L (502cid) the timing needs to be set to 8 degrees BTDC while in "Service Mode".

To get into Service mode you'll need a Scan Tool or what MerCruiser refers to a Timing Tool, part number 91-805747A1. The Timing Tool is a connector with two pins jumpered together. It plugs into the same port as a Scan Tool - Data Link Connector.

With the engine in Service Mode the ignition advance is held steady and the RPMs will jump up to 1800rpm. The RPM increase will only happen on MEFI-2 and MEFI-3 revision ECMs. If yours is an MEFI-1 you need to manually adjust the throttle to 1800rpms. Now your ready for the timing light.
 
It's different for different engines and ignition systems. For example my carbureted 4.3 with TBIV ignition is simple, there is a lead off the distributor that you ground out and the can use and old fashion timing light. EFI and newer engines you have to use either a Mercury too or scan too that plugs into the ignition system and puts it in service mode. Some engines you don't really adjust the timing, there is a crankshaft position sensor and the ECM adjusts the timing based on that. You need to look the the instructions for your specific motor.
 
do you have the serial number of the engine

Where is the serial number? I suppose on the block somewhere but I havent found it.
 

Forum statistics

Threads
112,946
Messages
1,422,785
Members
60,930
Latest member
Ebrown69
Back
Top