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Please HELP me get my EFI running

Did this engine come with the Starter installed or was it converted? I have to pull a book and see if their is a difference....

If the engine was a pull start originally, it will take two pulls of the rope to start it... On pull charges and wakes everything and the next pull starts... When testing the injectors crank the engine with the key start and then crank it again.... Remove you aftermarket kill switch....
 
Chris,

I think, based on the engine model number, it was a remote control engine from the beginning. These Mercury 25/30 HP EFIs do have a pull start also. I think all the electric/key start/remote models came with a pull start. Yes, it takes the first pull to charge the system, then it starts on the second. But I have been using my battery and remote. I did try the pull start yesterday, nothing.

I checked the kill switch and when I actuate it (remove lanyard) the oil pressure light does not come on when cranking. When I reset it, and crank, the oil pressure light comes on. And I connected by ohm/beep test lead to the brown kill switch circuit on the engine and the other end to ground. When the key is off, I get a beep/continuity, key on, no beep. Same when checking the kill switch. Leading me to believe that the kill switch works.

I tested everything in the factory manual that I can with a multimeter. I have some new out of spec readings. When I put the pos lead on the RED wire that goes to the rectifier, I do not get any readings with the black wire on any of the 3 yellow wires or ground. The manual says I should get around 5K OHMS.

Any chance a blown rectifier would not allow it to start? (I thought it would run without it since I have a battery that is charged).

Any chance the IAC valve is bad and causing it to not start?


Docksidemarineservices said:
Did this engine come with the Starter installed or was it converted? I have to pull a book and see if their is a difference....

If the engine was a pull start originally, it will take two pulls of the rope to start it... On pull charges and wakes everything and the next pull starts... When testing the injectors crank the engine with the key start and then crank it again.... Remove you aftermarket kill switch....
Click to expand...
 
I built a 3 cylinder spark board and connected all 3 plug wires to it. And connected the other end of the spark board to the ground bolt on cylinder #1 coil mount.

I see spark at the immediate beginning of cranking only. 2 or 3 sparks, then nothing, nada, I can crank all day longer and no more spark.

If I stop and crank again from stop, it again sparks 2 or 3 times only.


View attachment 23048

Here are the results of a few tests (# is cylinder that fired).

2, 1, 1
2
3, 1, 2
3, 1

After the above 4 tests, I reworked the spark board to enclose it with lexan, put dividers between the diff cylinder bolts, and insulate the exposed bolts near the boots. I wanted to ensure there was no cross firing.

1, 2
3, 1
 
I retested the resistance between each primary ignition coil lead (small black wire from ECU with color stripe) to ground.

All 3 read approximately 6.3 ohms. Lower than my reading the other day when it was warmer out of approx. 12 ohms. But still way higher than spec in the manual.

Is there a way to test the voltage from the ECU to the primary wire of each coil? To see if the ECU is calling for the cylinders to fire?
 
boardhauler said:
I retested the resistance between each primary ignition coil lead (small black wire from ECU with color stripe) to ground.

All 3 read approximately 6.3 ohms. Lower than my reading the other day when it was warmer out of approx. 12 ohms. But still way higher than spec in the manual.

Is there a way to test the voltage from the ECU to the primary wire of each coil? To see if the ECU is calling for the cylinders to fire?
Click to expand...
I know you said the tach jumps when you crank the engine.... Does it continue to jump with extended cranking or does it stop?
 
don't want to hyjack thread,
Docksidemarineservices tried to PM you, wouldn't let it go through it said your message box was full and you needed to remove some in order to receive more messages
 
Chris,

The last time I cranked it the tach jumped up and then down, did some bouncing around.

One Mercury service center (I dropped it off) didn't have the right cable to connect to the ECU. UGGGGG!

Another that I called, said the computer is worthless at troubleshooting anyways. He also said he had similar problems with a similar engine and replaced the ECU and HP pump (Mercury techs told him to or the HP pump would kill the new ECU, which apparently is common). He still had problems and in the end put a used crank pulser on and it ran great.

This is getting really aggravating. I don't know why x2 so called high level Mercury service centers do not use the computer to diagnose issues. AND it is crazy that Mercury not only stopped making the highly expensive ECUs, but has told mechs that the HP fuel pump kills ECUs. 2 of the most expensive parts in the engine don't play well together??? Seems like they did not do some basic circuit protection fuses or capacitors.
 
boardhauler said:
Chris,

The last time I cranked it the tach jumped up and then down, did some bouncing around.

One Mercury service center (I dropped it off) didn't have the right cable to connect to the ECU. UGGGGG!

Another that I called, said the computer is worthless at troubleshooting anyways. He also said he had similar problems with a similar engine and replaced the ECU and HP pump (Mercury techs told him to or the HP pump would kill the new ECU, which apparently is common). He still had problems and in the end put a used crank pulser on and it ran great.

This is getting really aggravating. I don't know why x2 so called high level Mercury service centers do not use the computer to diagnose issues. AND it is crazy that Mercury not only stopped making the highly expensive ECUs, but has told mechs that the HP fuel pump kills ECUs. 2 of the most expensive parts in the engine don't play well together??? Seems like they did not do some basic circuit protection fuses or capacitors.
Click to expand...

If the tach is dropping during cranking then the CPS may be faulty.... Where are you located?
 
boardhauler said:
Chris,

Saint Augustine, Florida.
Click to expand...

This is the type of problem that needs a hands on experienced tech.... Problem is finding a shop in your area.... My suppliers in FL complain about the same issue.

Source a Crank Position Sensor....worth a try .... The Tach should not stop moving during cranking........
 
Chris,

It looks like we have a high demand for experienced Marine techs around here, know anyone who wants to relocate?

I replaced both Pulsers (Crank position sensors). I tested/cranked the engine after each.

After I replaced the 2 wire sensor, the tach was jumping up to around 500 rpms then dropping no matter how long I cranked it.

After replacing the second sensor (1 wire), the tach jumps up to 1000 rpms when cranking but still drops off quick and never comes back no matter how long I hold the key/crank it.

I now have a spare Alternator/stator. I guess I will try swapping it out next.

If that doesn't work, it seems pretty clear that the ECU is shot.





Docksidemarineservices said:
This is the type of problem that needs a hands on experienced tech.... Problem is finding a shop in your area.... My suppliers in FL complain about the same issue.

Source a Crank Position Sensor....worth a try .... The Tach should not stop moving during cranking........
Click to expand...
 
Last edited:
Chris,

UPDATE:

I have now replaced both pulser coils and the Stator. I bench checked both Stators with my ohm meter and they read the same.

After reassembly, I tapped the ECU with my knuckle, thinking (maybe there is something loose in there) and it tried to start (I hear it pop one or two times).
The next try, nothing
tapped the ECU again, and again a few pops (got it to do this 3 times by tapping)
Then nothing, back to the same old story.

I checked compression and it is 50 PSI on ALL 3 cylinders. Seems low to me. But, I can not find a spec/range in the factory manual. I'll check with another gauge tomorrow.



Docksidemarineservices said:
This is the type of problem that needs a hands on experienced tech.... Problem is finding a shop in your area.... My suppliers in FL complain about the same issue.

Source a Crank Position Sensor....worth a try .... The Tach should not stop moving during cranking........
Click to expand...
 
boardhauler said:
Chris,

UPDATE:

I have now replaced both pulser coils and the Stator. I bench checked both Stators with my ohm meter and they read the same.

After reassembly, I tapped the ECU with my knuckle, thinking (maybe there is something loose in there) and it tried to start (I hear it pop one or two times).
The next try, nothing
tapped the ECU again, and again a few pops (got it to do this 3 times by tapping)
Then nothing, back to the same old story.

I checked compression and it is 50 PSI on ALL 3 cylinders. Seems low to me. But, I can not find a spec/range in the factory manual. I'll check with another gauge tomorrow.
Click to expand...


Your engine may have a compression release that helps with the pull start....
 
Chris,

Ok, checked compression AGAIN with a 3RD gauge. I tried to open the intake/throttle, but it would not easily move. So these tests are with it closed.

Cylinder
1 100 PSI
2 110 PSI
3 110 PSI

The factory manual says a reading below 120 PSI means overall engine wear and Good is 154-180 PSI (Bad 141-170 PSI)

But it also notes that these numbers are not specific to this engine.

For general reference, this engine looks like is have very very low hours of use. It is very clean and looks new other than a little paint rubbed of the strake/fin.



Docksidemarineservices said:
Your engine may have a compression release that helps with the pull start....
Click to expand...
 
Last edited:
boardhauler said:
Chris,

Ok, checked compression AGAIN with a 3RD gauge. I tried to open the intake/throttle, but it would not easily move. So these tests are with it closed.

Cylinder
1 100 PSI
2 110 PSI
3 110 PSI

The factory manual says a reading below 120 PSI means overall engine wear and Good is 154-180 PSI (Bad 141-170 PSI)

But it also notes that these numbers are not specific to this engine.

For general reference, this engine looks like is have very very low hours of use. It is very clean and looks new other than a little paint rubbed of the strake/fin.
Click to expand...


I cannot get into the shop to get the manual for this specific engine due to the Wuhan flu.... I would say your engine has a compression release... and these numbers are not correct....
 
Chris,

Thanks for your help. I charged the battery fully and opened up the intake butterfly, rechecked and the compression is still the same.

I rotated each cylinder to top dead center, using the camshaft markings and feeling with a pencil, connected the compression hose with 100psi from my compressor, and I do not hear any leaks, on any cylinders.

But, I attempted to rotate each cylinder to its exhaust cycle and they still hold pressure. I expected it to release??????



Docksidemarineservices said:
I cannot get into the shop to get the manual for this specific engine due to the Wuhan flu.... I would say your engine has a compression release... and these numbers are not correct....
Click to expand...
 
A new development

I had previously cleaned some mud robber nest material (dried mud/sand) out of the idle exhaust.

I inspected it closer today and I had not gotten it all out. It was sealed shut. I don't think this could have caused my recent issues, but maybe the idle problems I had previously.

Or, it could have caused some other issue.

I have not opened the entire idle exhaust plate yet.

Docksidemarineservices said:
I cannot get into the shop to get the manual for this specific engine due to the Wuhan flu.... I would say your engine has a compression release... and these numbers are not correct....
Click to expand...
 
boardhauler said:
Chris,

Thanks for your help. I charged the battery fully and opened up the intake butterfly, rechecked and the compression is still the same.

I rotated each cylinder to top dead center, using the camshaft markings and feeling with a pencil, connected the compression hose with 100psi from my compressor, and I do not hear any leaks, on any cylinders.

But, I attempted to rotate each cylinder to its exhaust cycle and they still hold pressure. I expected it to release??????
Click to expand...


I think the compression tester I was using had a one way valve. I'll have to re-test the leak down/air compressor.
 
boardhauler said:
I think the compression tester I was using had a one way valve. I'll have to re-test the leak down/air compressor.
Click to expand...

It does, It has a schrader valve like a car tire valve stem..... FYI, Do not lose the valve, although it looks and functions the same it cannot be replaced by a tire valve..... The spring pressure on the schrader is calibrated to work with your comp testor.
 
Here is where I am at..................

Has anyone had an issue with a 25 or 30 HP 4 stroke that would not start?

I have a Mercury 30 HP EFI ELPT 2007. It is the same engine as the Tohatsu and Nissans.

I got it used. It ran OK for 2 times out on the water. The second trip it shut down and would not start.

I get no pop when trying to start it (electric start). The tach jumps up to 500-1000 rpms and drops quick to zero.

I checked spark and see it spark 2-3 cylinders then nothing.

I have been through everything that I can think of. Checking with factory manual (Mercury) which seems to list the incorrect Ohm values for almost everything.

Coils
entire fuel system (incl. repairing regulator that was stuck open, new filters, checked injectors and screens, HP pump, float and seat, etc.)
Fuel rail pressure is 40+ psi, solid.
IAC, IAtemp sensor
oil pressure switch
temperature sensor
fuse
wiring
plugs (new), old ones looked fine.
charge regulator
remote controls (they are new) & wiring
kill switch & entire circuit
battery (full charged)
I can see the number one cylinder exhaust port open and close when I rotate the engine by hand.
idle exhaust port (was plugged with mud dobber nest)
compression (reading 110 psi)

I replaced the pulser sensors and stator for fun, and after I tapped the ECU and it popped 2 times, then nothing, can not get it to repeat.

I think it is the ECU. I have been looking for a used one, and everyone says they are getting tons of calls for them.
 
boardhauler said:
Here is where I am at..................

Has anyone had an issue with a 25 or 30 HP 4 stroke that would not start?

I have a Mercury 30 HP EFI ELPT 2007. It is the same engine as the Tohatsu and Nissans.

I got it used. It ran OK for 2 times out on the water. The second trip it shut down and would not start.

I get no pop when trying to start it (electric start). The tach jumps up to 500-1000 rpms and drops quick to zero.

I checked spark and see it spark 2-3 cylinders then nothing.

I have been through everything that I can think of. Checking with factory manual (Mercury) which seems to list the incorrect Ohm values for almost everything.

Coils
entire fuel system (incl. repairing regulator that was stuck open, new filters, checked injectors and screens, HP pump, float and seat, etc.)
Fuel rail pressure is 40+ psi, solid.
IAC, IAtemp sensor
oil pressure switch
temperature sensor
fuse
wiring
plugs (new), old ones looked fine.
charge regulator
remote controls (they are new) & wiring
kill switch & entire circuit
battery (full charged)
I can see the number one cylinder exhaust port open and close when I rotate the engine by hand.
idle exhaust port (was plugged with mud dobber nest)
compression (reading 110 psi)

I replaced the pulser sensors and stator for fun, and after I tapped the ECU and it popped 2 times, then nothing, can not get it to repeat.

I think it is the ECU. I have been looking for a used one, and everyone says they are getting tons of calls for them.
Click to expand...


Sorry we have dead ended with this issue on your engine, There is only so much that can be done through a Keyboard.... If you were local to me I could just pull an ECU and test what we both have concluded to.
 
Chris,

Thanks for all your help.

I ordered a ECU today.

I am going to check all the wiring between the sensors, fuel pump, injectors, coil, etc. back to the ECU plug just to make 100% sure there are not shorts.

No, I am just trying to decide if I should replace the HP fuel pump with the ECU. With only + and - going to it, I can't see it blowing a ECU. But, if the HP pump seized up, maybe it could backed more power to the ECU than it was prepared to handle.


Docksidemarineservices said:
Sorry we have dead ended with this issue on your engine, There is only so much that can be done through a Keyboard.... If you were local to me I could just pull an ECU and test what we both have concluded to.
Click to expand...
 
Dockside suggested using some quick start into the intake when cranking to see if it pops. I didn't see a response to that.

We're you able to run that test?

That should help to eliminate part of where the problem(s) is coming from.

--JR--
 
No, I have not tried starting fluid in the intake. I don't want to damage anything and I am only getting a weak spark 2 or 3 times when cranking, then no spark. The injectors do not have 12v power to them either.



--JR-- said:
Dockside suggested using some quick start into the intake when cranking to see if it pops. I didn't see a response to that.

We're you able to run that test?

That should help to eliminate part of where the problem(s) is coming from.

--JR--
Click to expand...
 
No problem!

Just sounded like you went through a lot of checks and a lot of frustration. A failure of both ignition and fuel isn't very common from my experience. But they are both controlled by the ECU on newer engines. Double failure like that even on an ECU is a little rare too. Sensor failure usually causes loss of both as the ECU doesn't know what to do.

But I'm not familiar with your engine or how it's ECU operates.

I hope your replacement ECU does the trick!
 
Got the Rinda Techmate Pro today. Hooked it up and it says the engine needs to be running to test it? Uggggggh. If I click "yes" it is running, it tells me the ECU number and 0.0 running hours.
 
Just throwing this out there. Does that motor have the fuel injector delivery chamber on starboard side of motor that hp fuel line goes to from vst , then has individual hoses to each injectors ?
 
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