Desperate for help with timing problems on 3.0

[Rake722]

Good evening all I’ve been working every night on this boat until 11 o’clock at night after a full days work the problem we are having is that initially we could not get the engine to go into base timing mode while connecting the jumper between the two white Leeds on the distributor with the engine idling at full operating temperature and then connecting the harness wires for the shift interrupt again they made no change whatsoever to engine rpm.

I stopped the engine disconnected the jumper and reconnected the harness wires and the boat would not start I checked the spark and there was no spark with the jumper disconnected and then reconnected the jumper and there was spark that indicated to me that there was a problem with the ignition module so I replaced it.

lo and behold with a jumper wire disconnected we had a good spark and the engine run very sweetly so I set the balancer notch to top dead centre on firing/for cylinder one. I then found the factory marks for the distributor and aligned them and nipped up the distributor I then started the engine and it ran nicely at 600 rpm. Now here comes the issue I let the engine reach operating temperature at idle I reconnected the jumper cable to the new ignition module and did the engine harness at the shift interrupt again and lo and behold there was no change in engine tone I checked the timing with my strobe and the notch on the balancer was miles away from the timing marks on the plate. I loosened the distributor and rotated the distributor counterclockwise and the notch on the balancer appeared so I set it to 1° before top dead centre I then stopped the engine disconnected the jumper reconnected the interrupted harness wires and went to check the timing again it had advanced to about 8° after top dead centre,

so it appears that I can’t set the timing will get this into base timing mode and I’m struggling for reasons why and this boat has to get to Greece on Tuesday next week but I can’t send it in this condition.

Is there any other part of the distributor electronic assembly such as the coil or pole plate that could cause a condition where FaceTimeing mode is unachievable is there any other part of the distributor electronic assembly such as the coil or pole plate that could cause a condition where FaceTimeing mode is unachievable? What could be the problem here

Any ideas would be gratefully received thank you

link to last thread I posted that could be related but that’s fixed now

https://forums.iboats.com/forum/eng...02-nose-blown-of-new-aftermarket-starter-3-0l

 

[alldodge]

You should link your other thread to this one, so others can review the entire story

 

[Rake722]

Okay so today I had another go at it firstly I reset the timing on the distributor with cylinder one top dead centre firing stroke.
I made sure the jumper wire was not connected and that the engine harness for the shift interrupt was disconnected simulating normal running conditions. I connected the timing light zero advance and surely Enough the timing was at 1° before top dead centre.Enough the timing was at 1° before top dead centre. I then connected jumper wire to the distributor wires and connected the shift interiupt purple and white green together on the engine harness. I took my multimeter and confirmed 12 v to the distributor on the black wire. Yet again there was no change in engine tone so I took my timing light and the timing mark was still at 1° before top dead centre.

I switched off the engine and disconnected jumper and reconnected the shift interrupt as normal. I started the engine again and checked with the timing light and confirmed that the timing was still 1° before top dead centre so it appears that the distributor is not advancing as it should do
I would be very grateful for anybody’s opinion to me it seems like the replacement module that are used is also not working.

I also checked all electrical connections and continuity as per the manual and everything checks out

 

[alldodge]

I would be very grateful for anybody’s opinion to me it seems like the replacement module that are used is also not working.

I agree

 

[Rake722]

Thank you I need to get a Sierra one PDQ.

can I set the timing to 12 BTDC at 700 rpm like in the advance curve and use it for the time being ?

 

[alldodge]

can I set the timing to 12 BTDC at 700 rpm like in the advance curve and use it for the time being ?

I'll put it this way, you know its not advancing at idle when taken out of base timing mode.
If the timing also does not advance when motor increases rpm, then agree it will not damage the motor.

Now if all of a sudden it does start advancing, then it can

 

[Rake722]

I'll put it this way, you know its not advancing at idle when taken out of base timing mode.
If the timing also does not advance when motor increases rpm, then agree it will not damage the motor.

Now if all of a sudden it does start advancing, then it can

OK the boat is going to Greece Tuesday next week and I won’t have a chance to get a new module before it leaves so I am going to have to get a module and take my strobe with me to fit it and time it up while I’m am there on my holidays. It’s going to stay there indefinitely so need to be pretty darn sure the module is the problem.

im going to fit the old module tomorrow, that one didn’t spark with the jumper removed but also didn’t go in to base timing with it connected but it did spark so I’ll fit it and see if it advances correctly so maybe I can use that one until the new one arrived ??

jist looking for a temp workaround if you can help on that ?

thank you

 

[achris]

A faulty module could do a couple of things. Let's say the lack of base mode it just the first stage of a complete failure. That leaves the possibility of you being out and the engine stops running altogether. Not a good look.

The other possibliity is that all of a sudden the module starts advancing as it supposed to. That will leave the timing running at 12 degrees advanced of where it should be. On ANY engine that's not a good thing. In a marine engine which is under load all the time, that is guaranteed to blow the head gasket, and /or knock a hole in a piston. And worst of all, you won't hear a thing until it all stops going round.

Safest thing. Don't use the boat! Or it could become a VERY expensive holiday....

Chris.......

 

[Rake722]

An update I went and played with it again today and with the shunt why are disconnected 600 rpm the timing rate is 1° before top dead centre. I used the advance function on my strobe and clocked the timing at 1500 rpm at around 12° before top dead centre which means that this module is advancing almost correctly despite not being able to go into base timing mode. I then checked advances about 3800 rpm which was around 30° before top dead centre which is only three or 4° shy of the specified advance at 4000 rpm.


I will of course be purchasing a replacement ignition module but with that level of advance would it be safe to use in the meantime or would it still be subject to going bonkers at any moment ?

 

[alldodge]

Yes, but the big IF
If it does not go further advance then what your seeing, then all good

 

[Rake722]

Thanks alldodge, at least we can use the boat till the new module arrives.

ill be taking my strobe, torque wrench and 9/16 with me and check advance daily

 

[alldodge]

torque wrench and 9/16 with me

:nono: not good, its in Greece, their metric only ound:

Ok that was a bad joke :facepalm:

 

[achris]

:facepalm:

If that module fails and over advances the timing, it's not days of notice you'll get. The engine will be destroyed in about 2 minutes... Probably less.

Use the boat, don't use the boat. That is your choice. If it were mine, that boat wouldn't be going anywhere until the ignition system was fixed and confirmed working properly. For me, it's just not worth the risk...

Chris...

 

[Rake722]

:facepalm:

If that module fails and over advances the timing, it's not days of notice you'll get. The engine will be destroyed in about 2 minutes... Probably less.

Use the boat, don't use the boat. That is your choice. If it were mine, that boat wouldn't be going anywhere until the ignition system was fixed and confirmed working properly. For me, it's just not worth the risk...

Chris...

well today brought a bit of a revelation I managed to acquire an original module from another boat and lo and behold it went into base timing and I was able to time the engine correctly.

The module l is from the later model but I believe the timing advance curves are all the same so it should be alright and I also checked timing at 1000 rpm was 13° in line with the specifications below is a video of the vessel


https://youtu.be/OZ_4zBomMnQ

 

[alldodge]

Cool beans

 

[Rake722]

I’m grateful for all the help you guys have given.
this has been quite an undertaking to do in 3 months under lockdown and while having a full time job.

full trailer fix
head work
new manifold and riser
out drive 300 hr service
carb rebuild
shift cables
thrittle cables and adjustment
mounting aux engine bracket
rewire
new cover
news starter
distriv module and troubleshooting
vhf install
new battery
trim pump service
Trim pump bracket
skeg rebuild and welding
upholstery
the list goes on