Logo
FULL SITE MENU

Trouble after rebuild

V6 and V8 EFI Models (EFI Ignition)
Two items of test equipment are required: an inductive pickup timing light and one of either a Scan Tool, Marine Diagnostic Code Tool or MerCruiser Special Timing Tool (Quicksilver 91-805747A1).
1. Connect timing light (91-99379 or similar) to No. 1 spark plug wire. Connect power supply leads, if applicable, on light to 12 volt battery. Refer to Specifications – “Engine Rotation and Firing Order,” for cylinder numbering and location.
2. Connect a shop tachometer to engine.
NOTE: Before starting engine make sure the timing tab and mark, or marks, on crankshaft damper are clean. Chalk or white paint on timing marks may help visibility.
NOTE: If NOT Using MerCruiser Timing Tool: With engine running, set the scan tool or Marine Diagnostic Code Tool to the SERVICE MODE and follow manufacturer’s instructions. On 350 Mag MPI Model, engine RPM will automatically increase to a higher RPM. You do not have to increase it manually, as stated in the following steps.
3. Connect the Timing Tool (or appropriate tool, as listed above) to the DLC connector (in the electrical box or on the electrical bracket) of the wiring harness.
4. Start the engine. Allow it to reach normal operating temperature.
5. On all models except 350 Mag MPI: Manually adjust the engine throttle to 1800 RPM.
6. Aim timing light at timing tab, located on the timing gear cover and crankshaft torsional damper. Check the timing. Refer to “Specifications.”
7. Loosen the distributor clamp bolt enough to just be able to rotate the distributor with some resistance.
8. Aim timing light at timing tab and recheck location of timing mark. Slowly rotate the distributor clockwise or counterclockwise to adjust the timing to specified degrees.
9. Aim timing light at timing tab and recheck location of timing mark. Repeat Step 8 until timing is correct. Torque distributor hold down bolt to 30 lb. ft. (40 N.m).
10. Manually close the throttle to bring engine RPM back to idle.
IMPORTANT: Be sure to disconnect MerCruiser Special Timing Tool from the DLC connector, or set the tool to NORMAL MODE if using the Scan Tool or Marine Diagnostic Code Tool, before attempting to resume normal operations. If the MerCruiser Special Timing Tool is left in pace or the setting of the tool remains in SERVICE MODE, the ignition system will operate only in the “Service Mode”. This means that the additional timing advance features would not function.
11. Disconnect the MerCruiser Special Timing Tool from the DLC connector. If using the Scan Tool or Marine Diagnostic Code Tool, set the tool to NORMAL MODE. Disconnect the tool.
12. Stop the engine. Turn ignition key to OFF position.
13. Remove timing light.
 
Good info from Pappys......... however, let's not forgot to mention the importance of checking the progressive and total advance at the rpm that each should occur.

BASE advance is BASE advance. We fire up on BASE and we idle on BASE.
The more important numbers occur above and beyond BASE advance, and in particular within the RPM range where Detonation is more likely to occur.
Most systems will delivery this correctly ....... but I believe that we should always verify the progressive and TA as per correct RPM.



.
 
Last edited:
I also remember reading that some mechanics actual set the timing at full advance at a certain RPM and not bother doing it at idle or do l have that wrong.

back to mine though, l would say my timing is close enough for now as it starts first kick first start of the day. I can sort that more accurately later after l sort these other issues.

no water through engine- l have worked out so far you can't use muffs on this set up so l will be setting up a tank today and trying that.

once started engine starts missing and then shuts down - l think this is associated with above

oil px isn't indicating

oil px alarm doesn't work
 
http://www.ebay.com/itm/Mercruiser-...ash=item3606a06b06:g:jtEAAOSwImpXpKmS&vxp=mtr
Do you have two connectors on the distributor? If so and you think its close enough it aint. Ignition timing is totally controlled by the computer you can not just put a light on and guess it is correct. You must follow the proper procedure or hire a mechanic to do so. Your not only timing the ignition but you are also putting the injectors in sync. Is that a throttle body injected system? If so it is likely a 1998 model.
 
Gents please don't get me wrong wrong but l have issues to deal with BEFORE it is tuned properly for see trials ( and it will be)

as you would/ should agree getting water into the engine is the priority atm, l just tried it in a water tank and it won't pump it up motoring it, l don't want go starting it again until l have water in the head and block or do you disagree

is there a way of priming the whole system or tapping into the system somewhere for flushing/cooling other than using muffs on the leg

The horn issue seems to be the wiring so will work on that

Th oil pressure seems to the sender so will have to get a new one
 
A few clarifications please... Is it FWC or RAW?... Which drive? Alpha?... Bravo???.
In either case, running for just a few seconds without water will "eat" the impeller on the raw water pump. The fact that some water flows while on a muff ( pressurized water flow from hose), and none while drive is in a bucket, ( raw water pump does all the work), leads me to think the raw water pump impeller is "toast". It is vital that you account for any missing pieces of the raw water pump's impeller. They have a habit of ending up in ugly, flow restricting, places ( most notably in the t'stat housing or in the exhaust elbow's water dump hole into the exhaust stream).

To directly answer your question... with a properly working system, there is no need to "prime" the system. Alpha and Bravo drives have different "issues", hence my query.
 
Last edited:
...........................
burls said:
I also remember reading that some mechanics actual set the timing at full advance at a certain RPM
Yes....... you have just mentioned how a "seasoned" Marine Mechanic will have checked/adjusted Ignition Advance for the Progressive and TA @ the OEM specified RPM.

and not bother doing it at idle or do l have that wrong.
Not exactly. We are also concerned with BASE or Initial advance as well.

Adjustments can be made so that both work in harmony..... but you are correct......... the Progressive and Total Advance at a specified RPM are of greater importance!



back to mine though, l would say my timing is close enough for now as it starts first kick first start of the day. I can sort that more accurately later after l sort these other issues.
Keep in mind that spark lead (spark advance) has the last word re; the LPCP.
Also keep in mind that Ignition Induced Detonation (under marine loads) can be extremely damaging.

I would put Ignition Advance at the TOP of your list, and put the other items further down the list!
Click to expand...
 
Ahh my saga continues.......

But firstly it's an alpha gen 2 leg and straight sea water not heat exchanger sorry did not want to guess RWC, FWC, RAW

And it is twin barrel throttle body injection. Impeller is new and as l had it apart yesterday looking for blockage- no damage.

so back at it.....

was going to see if l could start it and get the water pumping but l've lost power again to the middle fuse which leads to me back to the start again.

Time for a beer and a think, l recon
 
I would not worry about all that timing stuff with the exception of setting the base timing as described in the quoted factory info by fatzbullet.

Once you set the base (typically jumping two leads together or possibly by software toggle with scan tool) and then setting base to specification, then removing jumper or toggle software, then the ECM will take over from there. Not much you can do about it.


You seem to be going around in circles.........

keep the posts up and try to be a specific as possible.
 
Ha ha, l've definitely had some some fun with this project that's for sure.

l still don't get it about ensuring all the timing stuff is done before it all works. It starts first kick so that's good enough for me until l sort out all the problems unless someone can explain why it's not ok.

Had a good day though today managed to get power back (found another damaged wire behind the run switch). Fixed that and got the power back to the ign relay. So started it in a big bucket and now it pumps water. I had the pipe on the back of the steering cooler off and once there was water there l shut the engine down. Did this to the hose on the water pump. Will do some more tomorrow. I'm also going to get a good quality set of muffs and see if they work as well.
still working on the warning horn wiring and won't be running it again for more than a few seconds until that is fixed and operational.
 
I would not worry about all that timing stuff with the exception of setting the base timing as described in the quoted factory info by fatzbullet.
Click to expand...

In my opinion, this is what sets the difference between well seasoned and non-seasoned mechanics.
A seasoned mechanic will set BASE and will also take a look at the Progressive and TA as to verify.

If you do not understand Ignition Advance and the importance of it.......... you should not be doing Marine Engine work for anyone but yourself!
 
RicardoMarine said:
Good info from Pappys......... however, let's not forgot to mention the importance of checking the progressive and total advance at the rpm that each should occur.

BASE advance is BASE advance. We fire up on BASE and we idle on BASE.
The more important numbers occur above and beyond BASE advance, and in particular within the RPM range where Detonation is more likely to occur.
Most systems will delivery this correctly ....... but I believe that we should always verify the progressive and TA as per correct RPM.



.
Click to expand...

Hey Rick,

On a newer 555 EFI engines there are no provisions for checking base timing for the everyday user. You will need timing tape and a Hall effect light to check this. The way the system is designed allows for the high speed switch (distributor) to be dropped in close(within a few degrees) and the ecm does the rest.

Now, when these engines get some hours on them, the timing chain loosens up a bit, and then the the HSS needs to be indexed perfectly to correct performance issues.
 
Last edited:
We are just saying you need to adjust the timing as soon as you get it running good that includes cooling. If you know the impeller is good and it is not pulling water up are you sure you have the impeller installed properly? Figure out what direction the engine spins the pump and make sure you spin the pump that direction when installing the impeller. Put a squirt of dish soap in the pump so the impeller has lube until the water gets there. All it takes is a small air leak to keep the pump from priming itself. Are the hoses still soft and all the nipple ends in good shape? Did you replace the o-rings for the pump housing and plate? As far as the timing it is a go no go senario. Install the jumper connector or put on a scan tool and switch it into timing mode. Have your timing light ready and start the engine. Bring the rpms up to 1200 rpms and set the timing at 8 degrees BTDC and let the engine fully warm up at 1200 rpms. Confirm the timing is at 8 degrees and lock the distributor down. Disconnect the jumper and the and the throttle cable at the TB. The computer should take control of engine idle. The ignition has a knock senser to test if the knock senser is working watch the timing with the timing light and tap on the block next to the knock senser the timing should retard with the tapping. It is not a mechanical advance so the standard way to check max timing advance is useless. The computer advances the timing to the point of detonation the knock senser hears it and slightly retards the timing. If no knock is sensed it will throw a code so having a code reader is a real good tool to have on hand with a EFI type engine. Do not tap on the knock senser as they are real brittle.
 
Was water pump housing sealed when impeller was replaced, Was entire pump replaced,not just impeller. What's temperature of heads when running,temp. of water exiting thru hub exhaust? Is she really running too hot? Time for a infrared temp gun if gauges are not working
 
This rig has a lot of issues and I'm trying to work through them but it is a slow process.

I put a new alarm on this morning and also got water through to the exhaust riser elbows on first start.
I believe l can now tick off the cooling issue so that's a start.

l am still have a lot of electricity issues especially relating to the early issue of no power at the ign relay. At least now l can tell as when it is all working as l get the alarm and the fuel pump when l turn the key on, unfortunately it is now becoming intermittent. I have pull all th plugs apart and cleaned th m again with contact cleaner. I will spray them with Deoxit when l can find it.
 
John

only the impeller was changed, housing and plate ok and resealed. Not sure what temp it got to but exhaust was hot. I haven't run it long enough since sorting the water flow issue to except to say l know for sure now there is water going through the engine to the exhaust
l have an infrared temp sensor so will keep that on standby from now on.
 
FWIW, I dislike muffs...
1) They can hide certain impeller issues since the hose pressure in and of itself will provide water flow with a dodgy impeller/pump.

2) My nephew's muffs slipped off while he was checking the timing and running the boat in his yard, alone, a couple of seasons ago... During the 30 or 40 seconds it took him to realize the muffs fell off, and shut the boat down, he "ate" his new impeller.
 
Funny thing was only one post mentioned the muffs when l had cooling problems. I'm a ex two strokes and muffs work fine on them. The only way to flush properly is with muffs so to me they are a must. I went and bought a set which pump in from both sides, I'll see how they go but for the rest of my setting up l will use the tank.
what dielectric grease should l get, l have seen DC4 in the shops around here?

Happy new year you everyone
 
burls, running from tank also provides back pressure on exhaust, closer to real life conditions on open water, Make sure a running hose is inserted in drum, have forgotten hose myself ,caught it in time,, Redirecting telltale stream back in drum results in too many exhaust bubbles,thus less cooling effect
 
..................................
burls said:
Thanks John but what l don't understand how detonationing out trumps cooking an engine due to no cooling.
Click to expand...
It does not necessarily out-trump damage from over-heating! Neither is good!

Common things that will toast a Marine Engine:
Lack of proper oiling (i.e., lubrication).
Over-heating.
Detonation.

Then we could go on to mention incorrect over-all gear reduction, over-propping, over-revving, lean fuel/air mixture and so on!

In spite of what you may read on the Internet, Detonation and Pre-Ignition are two different phenomena.

SBC Marine Engine Detonation can be caused by:
a poorly designed combustion chamber (i.e., automotive piston profile = no quench area).
use of low octane gasoline while under Marine loads.

Detonation = an uncontrolled burn within the chamber. It raises cylinder temperatures and it will eventually and severely damage the tops of pistons and possibly more.

Say NO to these:
attachment.php


kimcrwbr1 said:
We are just saying you need to adjust the timing as soon as you get it running good that includes cooling. If you know the impeller is good and it is not pulling water up are you sure you have the impeller installed properly? Figure out what direction the engine spins the pump and make sure you spin the pump that direction when installing the impeller. Put a squirt of dish soap in the pump so the impeller has lube until the water gets there. All it takes is a small air leak to keep the pump from priming itself.
Yes..... one small suction breach, and the impeller becomes helpless!

Are the hoses still soft and all the nipple ends in good shape? Did you replace the o-rings for the pump housing and plate? As far as the timing it is a go no go senario. Install the jumper connector or put on a scan tool and switch it into timing mode. Have your timing light ready and start the engine. Bring the rpms up to 1200 rpms and set the timing at 8 degrees BTDC and let the engine fully warm up at 1200 rpms. Confirm the timing is at 8 degrees and lock the distributor down. Disconnect the jumper and the and the throttle cable at the TB. The computer should take control of engine idle. The ignition has a knock senser to test if the knock senser is working watch the timing with the timing light and tap on the block next to the knock senser the timing should retard with the tapping. It is not a mechanical advance so the standard way to check max timing advance is useless. The computer advances the timing to the point of detonation the knock senser hears it and slightly retards the timing. If no knock is sensed it will throw a code so having a code reader is a real good tool to have on hand with a EFI type engine. Do not tap on the knock senser as they are real brittle.
Click to expand...

johnnygjr said:
Was water pump housing sealed when impeller was replaced, Was entire pump replaced,not just impeller. What's temperature of heads when running,temp. of water exiting thru hub exhaust? Is she really running too hot? Time for a infrared temp gun if gauges are not working
Click to expand...

burls said:
This rig has a lot of issues and I'm trying to work through them but it is a slow process.
Use the ole P of E ...... (process of elimination). Check/replace one item ONLY at a time.
If we start replacing things haphazardly, we may end up correcting the problem, but may not learn exactly which item did the trick! When used methodically and systematically, the P of E will not let you down, and you will be better prepaired in the future.

I put a new alarm on this morning and also got water through to the exhaust riser elbows on first start.
I believe l can now tick off the cooling issue so that's a start.

l am still have a lot of electricity issues especially relating to the early issue of no power at the ign relay. At least now l can tell as when it is all working as l get the alarm and the fuel pump when l turn the key on, unfortunately it is now becoming intermittent. I have pull all th plugs apart and cleaned th m again with contact cleaner. I will spray them with Deoxit when l can find it.
Again...... use the P of E!
Click to expand...
 
Last edited:
New Years greetings to one and all

I ended the year well
sorted the temping or water flow issues except l can't keep the drum full enough so only doing short runs ATM.
And the power issue with the ign relay - this turned out to be one of the loom connecting plugs under the dash. I cleaned all the plugs from rear to helm and used dielectric grease on all. Magic for about 5 minutes then I lost power again. I then one by one checked and fiddled with each plug and found the faulty one. I have manipulated it to work 100% but l think I will be change the plug just to be safe.
next issues I have is
the tach rose with RPM to about 3000 and that is where it has stayed there even after power off
The oil pressure is not reading - suspect the sender here
The fuel gauge is doesn't read

Then tidy up the wiring, plumbing and engine bay and sea trials well river actually
 
It is easy to test the senders just turn the ignition on and short the wire to the sender to ground the guage should fully peg on the needle. The senders are all 1 wire and should have close to battery voltage with the ignition switch to run. If you get voltage at the sender and the needle pegs when shorted to ground the sender is bad. If you get no voltage at the sender it is either the wiring or the guage thats bad. Some of those connectors just need a coaxing sometimes the pins just get pushed out a little just use a jewelers screwdriver and just push the pins in on both sides of the connector I would start at the one you know was giving you grief. All the guages sending wires likely go through that connector. The tach probably needs replaced when they act goofy it is normally permanent. Sounds like your making progress keep us posted.
 
johnnygjr said:
burls, running from tank also provides back pressure on exhaust, closer to real life conditions on open water, Make sure a running hose is inserted in drum, have forgotten hose myself ,caught it in time,, Redirecting telltale stream back in drum results in too many exhaust bubbles,thus less cooling effect
Click to expand...

kimcrwbr1 said:
We are just saying you need to adjust the timing as soon as you get it running good that includes cooling. If you know the impeller is good and it is not pulling water up are you sure you have the impeller installed properly? Figure out what direction the engine spins the pump and make sure you spin the pump that direction when installing the impeller. Put a squirt of dish soap in the pump so the impeller has lube until the water gets there. All it takes is a small air leak to keep the pump from priming itself. Are the hoses still soft and all the nipple ends in good shape? Did you replace the o-rings for the pump housing and plate? As far as the timing it is a go no go senario. Install the jumper connector or put on a scan tool and switch it into timing mode. Have your timing light ready and start the engine. Bring the rpms up to 1200 rpms and set the timing at 8 degrees BTDC and let the engine fully warm up at 1200 rpms. Confirm the timing is at 8 degrees and lock the distributor down. Disconnect the jumper and the and the throttle cable at the TB. The computer should take control of engine idle. The ignition has a knock senser to test if the knock senser is working watch the timing with the timing light and tap on the block next to the knock senser the timing should retard with the tapping. It is not a mechanical advance so the standard way to check max timing advance is useless. The computer advances the timing to the point of detonation the knock senser hears it and slightly retards the timing. If no knock is sensed it will throw a code so having a code reader is a real good tool to have on hand with a EFI type engine. Do not tap on the knock senser as they are real brittle.
Click to expand...

l won't be able to get the timing tool as there appears to be none around in Aus and the marine shop is still shut for summer. So can l do as mentioned above just jump wires within the interrogation plug and if so which wires?
 
After some research, l have found the wires to jump are A and B on the DLC plug.

Is this correct?

l hope l don't need to buy a new tacho.......
 
That would be my guess as well it looks like jump the black/white stripe and white/black stripe wires and bring the engine up to temp and adjust the timing at 8 degrees BTDC at 1200 rpms then lock the distributor down. Then just disconnect the jumper and see how well it idles. You can try switching the poles on the back of the tach just take note of the setting it is on and switch it to all the settings a couple times and return it to the original setting. If that fixes it just plan on getting a new tach in the near future it is likely to fail again. Can you borrow a timing light tach from your local auto part store to check the RMPS?
 
I ve fixed the oil px, the tacho, the fuel qty today so thought it was time to get on the timing. I ran the engine to warm it up and jumped wires A and B to put it in base mode as per some info on other pages l found and it would not start. It got close a few times but that's all. I removed the jump wire and it wouldn't start either
Any suggestions?
 
Back
Top