2003 PCM EX330 in 2003 SAN - Engine missing - running rough

[lbz99smp]

Hi,

Hoping someone may be able to offer some advice or point me in the right direction.

About 2 months or so ago we started having some issues; the engine would start missing a little when accelerating, started off barely noticeable and gradually got worst over a few weekend to the point where the boat was really struggling to get the rider up. We went through checked all the plugs, leads etc and noticed some moister in the distributor. Cleaned out the distributor and everything came good.

Then about a month or so ago same thing started to happen until gradually the boat would struggle to get the rider up again. So we replaced the distributor and rotor cap, test run the engine on the trailer and the engine seems to run fine up until 2500 rpm and then starts to miss and back fire, swapped the old cap and rotor back on and same result. We then water tested to see what happens. Boat runs fine up until 2500rpm or so, just as it starts to plane. Struggles to get on plan, but once on plane seems to run ok all the way through to 5000 rpm. Repeated the test on trailer. same result, except at 5000rpm engine without any load noticeable misses still.

So we have gone through checked all the leads, plugs, fuel pump and everything seems to be ok, not sure what else we can check..... Starting to think that it may be the ECU.......

Then our next problem, were in Australia and out nearest pcm dealer service center is about 700klms. (400miles) away. Not sure what diagnostic equipment is required to connect the engine to a computer to test the ECU. We have a plenty of local service centers for cars etc but no PCM specific service centers.

Does anyone know if the PCM computer connection is a specialized connection or generic to GM.? In Australia we have cars that have a GM based engines similar to the 5.7l PCM engine, not sure but this may be similar.

Also does anyone know if there is a workshop manual for the EX330. I have the owners manual and the part manual, however these aren’t that technical in relation to service. I'm thinking I might try a local mechanic, but I'd really need to give him all the information I can to help.

Any advice would be great. Thanks.

[wakejunky]

Just throwing it out. What about the knock sensor?


Chris

[AirTool]

Did the check engine light come on?

Do you have the recalled coil wire? (check pcm site or pn recall section)

There is also a recalled primary (low pressure) fuel pump. Check you pcm seriel number on that as well.

GM obd 2 tools won't work. You have to have the GM marine tools.

There is a PCM service manual available....it is mediocre at best.

If you are not turning on the check engine light, your problem is conventional and not related to control system. You'll need to check fuel system, plugs, ignition, vacuum leaks, etc.

One suggestion is to connect an inductive timing light to your coil wire and just watch the light (don't try to set the timing....you can't) but watch the light pattern....it should be perfect. Anything less than perfect indicates a problem with the ignition module or cap/rotor, etc.

[lbz99smp]

I'll check that one as well, any idea what the resistance should be for this sensor.....?

[lbz99smp]

Thanks for the suggestions guys.

The check engine light is on at the moment...... however I not sure if this relates to this issue......... :???: we had to replace the sump pan in the middle of last year due to corrosion around the sump drain, this required pulling the engine out. When we put the engine back in the check engine light came on and would not go off....... the engine ran without fault with normal temp, pressure, no faults or warnings. We have tried to find what is causing the engine light to come on, however have not been able to resolve it. Previous to the current problem the engine had run 6 months or more without fault.....as such we haven't followed up on the engine light issue......... ideally if we had a local dealer we would get this resolved asap.

My understanding the check engine light only relates to engine temp...... as per the SAN manual, we have replaced the engine temp sensor and still the light remains on.....
Does the check engine light relate to other sensors?

I don't believe we have the recalled coil wire, only came across this today searching the forums. We are in the serial numbers recalled so I'll have to chase that up. From PCM's site the fuel pumps area 2006 models only.

Any ideas where to source the PCM service manuals from?

[AirTool]

Code Reader

http://www.skidim.com/prodinfo.asp?number=RIN94008

Emissions/Fuel Book

http://www.skidim.com/prodinfo.asp?number=L510005

Engine hard parts repair

http://www.skidim.com/prodinfo.asp?number=L510015

Note you can't acutally set the "base timing" ....it should be called camshaft retard. The ignition timing on that engine is not adjustable.

[DanielC]

My gut feeling is that you have an ignition problem. It is hard to diagnose engines a half a world away.
If you could find a cooperative, and knowledgeable auto mechanic, that could take some testing equipment into the boat, and run it under a load.
Good luck in finding an engine specialist in drive ability and running problems. Expect to pay for one.
I would try to run the engine with an ignition scope monitoring the secondary ignition pattern.

The check engine light is important. It does monitor engine diagnostic codes. You can pull the codes in a similar manner to a GM OBD1 system. There is a connector under the plastic engine cover, that normally is attached to the Faria gateway box, that you can pull the codes from.
This connector is called an "Assembly Line Communications Link" or an "Assembly Line Diagnostic Link", the connector is also called by its acronym "ALCL" or "ALDL".
This is a 12 pin connector, two rows of six in a rectangle shape. Two of the corners are cut off, on one side of the connector, and there is a key tab on the other side of the connector in the middle. This connector has small letters, "A" through "M" identifying the connections. Look on top of the engine, to the left side of the centerline of the engine, forward of the fuel pump and computer relays. My directions are for a "direct drive" boat. Forward is the pulley end of the engine. If the engine is in a V-drive boat, the connector will still be on the left side of the engine, but on the Starboard side of the boat.

I remember the replacement coil wire being red. I could be wrong on that.

[AirTool]

My gut feeling is that you have an ignition problem. It is hard to diagnose engines a half a world away.
If you could find a cooperative, and knowledgeable auto mechanic, that could take some testing equipment into the boat, and run it under a load.
.....
I remember the replacement coil wire being red. I could be wrong on that.

DC - good post as usual. I believe you are correct on the coil wire color. If it is black it is either defective or replaced with a non-marine wire. In lieu of the scope, the timing light trick will usually show obvious problems.

Ditto on the auto mechanic - I almost posted earlier that he could consult a "better" auto manual for a 98 chevy truck with the vortec 5.7. Much of the goods are the same although the computer is not. I've got an old tahoe and the bulk of it all is the same. Diagnostics besides the ODB2 vs Faria would be similar.

Having the thrown codes would be handy. Another area common on the autos is problems or leaks with the plastic upper manifold cover....not sure if that has been a problem on the marine engines.

AirTool

[lbz99smp]

Thanks guys.

I'll order those manuals to get started. I have a pretty good auto mechanic here that I can work with. I also posted my troubles on an Australian forum; one of the guys on the forum has said that a shop/distributor of pcm engines in Australia has a laptop available for loan with the appropriate testing equipment. I'll give them a call to see if I can get a loan of it. Thanks again. I'll post any further information when it comes to hand.

[AirTool]

Thanks guys.

I'll order those manuals to get started. I have a pretty good auto mechanic here that I can work with. I also posted my troubles on an Australian forum; one of the guys on the forum has said that a shop/distributor of pcm engines in Australia has a laptop available for loan with the appropriate testing equipment. I'll give them a call to see if I can get a loan of it. Thanks again. I'll post any further information when it comes to hand.

Did you understand DanielC's instructions to pull the codes?

I'd do that straight away and the timing light test.

Fuel pressure test would be good as well.

Take two aspirin and call us in the morning.

[nms1991]

Which light is comming on? the actual check engine light or the low oil pressure for the v-drive? If the real check engine light is on check the low oil switch on the starboard side of the motor near the stock oil filter mounting pad where the remote oil filter hoses are hooked to. Disconnect the blueish green wires and test the motor with a load on it. To check the fuel pressure all you need is a standard fuel pressure gauge set, and the pressure should be 51 to 54 psi at idle and 57 to 62 psi at high rpm. If you are trying to look at the codes it is a special marine only style hook up and a special program to read the codes.

[lbz99smp]

Finally got our issue sorted out. after checking leads, spark plugs, compression test, leak down tests, checking for valve recession, sensors and so on our issue turned out to be the distributor.........from reading the pcm / nautique manual i was of the understanding the timming for the engine was fixed and couldn't be altered.....when i changed the distributor cap and rotor cap for some reason or other, i disconnected the plug attached to the rotar and also moved the rotor a fraction. not understanding that this actual controls the base timing which is adjustable...... :evil: so after all the testing etc the issue was resolved by rotating the distributor cap by about half a inch......

our first weekend back on the water and boat ran without issue. we do however still have the check engine light on. this was on before our last issue and still remains on. Also whilst trying to see what was going on we disconnected a number of sensors and reconnected them.

We now have warnings on the dash stating check . coolant sensor, map sensor and man air sensor. these each appeared when the sensor was disconnected and reconnected. We had a new coolant sensor on hand, replacing the sensor had no effect. My only thoughts are we have a issue with the faria gateway box......... I think we have had underlying issues with the gateway box for some time...... the air and water temps have always been off, we have never had analouge speedo read out, needle sits at 0mph. sometime ago our hours also jumped to 6500 or so and have continued to read from there......as all off these issue aren't critical we have never followed them up. My concern now is that we have engine related warnings showing, they don't currently effect the running of the boat,however if something was to go wrong we wouldnt know with false alarms showing.

Does anyone know how to reset the gateway box. or if the box can be tested.

Thanks again for all the suggestion and help.

[AirTool]

from reading the pcm / nautique manual i was of the understanding the timming for the engine was fixed and couldn't be altered.....when i changed the distributor cap and rotor cap for some reason or other, i disconnected the plug attached to the rotar and also moved the rotor a fraction. not understanding that this actual controls the base timing which is adjustable...... :evil: so after all the testing etc the issue was resolved by rotating the distributor cap by about half a inch.....

Sounds like your distributer hold down bolt was/is loose.

Just to clarify, turning the distributor does not change the "base timing". On that engine, ignition timing is in no way related to the distributor. Ignition timing is controlled by the the ECM with reference to the engine position obtained through the crankshaft position sensor. The adjustment you refer to is the camshaft retard and has a +2 to -2 degree tolerance. The Hall effect pick up inside the distributor is used to determine camshaft position and that info is used to determine when to pulse the fuel injectors.

You have to plug into the system to see this data.