Running rough after reflashed of ECM

[Spud]

Need some PN advice…

Our 2008 SAN Potentiometer failed so we installed a new one and had the engines ECM reflashed by PCM in SC to suit the new potentiometer.

Boat runs starts fine however has a miss a surf speeds. Above and below surf speeds it is fine

Our engine is in the range of engines in the 2007 - 2007 model years that had to have its Cam retard set to 6-8 degrees as per PCM service bulletin
SUP2009-01. See below….

My question is after PCM reflashed the ECM to suit the new potentiometer should the Cam Retard be left at 6-8 degrees or set at 0-4 degrees.

any help appreciated


#SUP2009-01
February, 2009
PCM Service Update PRODUCT INFORMATION UPDATE
Updated CAM Retard Specification for 2007-2008 Engines
Engines Affected: 2007-2008 5.0L MPI (Pro Sport) ALL 2007-2008 5.7L MPI (Excalibur) ALL
S/N: 470001-485993
This Product Information Update supercedes SUP2006-04, Information on Setting CAM Retard PCM 5.0L (Pro Ski) and 5.7L (Excalibur) engines, serial number range 470001 through 485993.
When rotating the distributor on the affected engine, you are adjusting what is called “CAM Retard.” This parameter represents the position of the distributor rotor relative to the proper terminal in the distributor cap when the spark is delivered. The specification indicated for this engine is 0-4 degrees. If the engine is set at 0 degrees, under certain precise RPM, temperature and load conditions, the engine can “crossfire.” This means the spark jumps to the wrong terminal within the distributor. This can cause a slight backfire or sputtering under this condition. To ensure this condition does not exist, CAM Retard should be set between 6-8 degrees on engines between serial numbers 470001-485993.
This is a correction made to the tune-up specifications and should be checked and set to specification during normal service intervals. A new specification decal needs to be installed after the adjustment is made. Contact PCM in order to receive updated specification decals, p/n R134170B-U, which indicates the correct CAM Retard specification.
NOTE: Engines built starting with serial number 485994 have been changed to a new specification (15 +/- 2 Degrees) and circuit diagnostics added. These engines DO NOT need to be changed.
In order to properly set the CAM retard, the following scan tool MUST be used:
PC Based Diagnostic Software: Diacom Diagnostic Software, Marine Edition, by Rinda Technologies, Inc. Available for purchase through PCM, P/N RT0086.
1. Connect the laptop to the engine’s data link connector.
2. Per the tool instructions, navigate the tool to view ECM data.
3. Find the engine parameter labeled “CAM Retard.”
4. Engine must be running in order to view the CAM Retard value.
5. CAM Retard value MUST be set between 6-8 degrees. If the value is within specifications, make sure the distributor hold down bolt is tight.
6. If the value is outside the specifications, loosen the distributor hold down bolt and slowly rotate the distributor until a value of 6-8 degrees is achieved. Tighten the hold down bolt securely, making sure the CAM Retard value does not go outside of the specification. Once the distributor hold down is tightened, verify the value still remains between 6-8 degrees.
Important: The basic principle that the distributor must be installed into the engine properly still exists. If the proper CAM Retard cannot be achieved, check the installation of the distributor.
7. Clean the surface of the old specification decal and install new specification decal, p/n R143170B-U.
Published by Pleasurecraft Engine Group Training Services. Pleasurecraft’s policy of continued improvement creates dated information and necessitates changes in procedures, specifications and methods used in trouble shooting and repair. In the event you have any questions regarding any of our products, the most up to date information may be obtained by contacting our service department to insure that any published information in your possession has not been updated. The information in the publication is believed to be true and correct at the time of publication. This publication is for informational purposes only and does not constitute a guarantee or warranty or in any way change or modify the written warranty, which is attached to
PCM Products at the time of sale. The knowledge of this publication, the information revealed herein and/or the possession of this publication grants no license or authority to anyone
to perform any action or make any statement or commitment, beyond the specific instructions stated herein, in behalf of or in the name of Pleasurecraft Engine Group. It is the sole responsibility of those using the information contained herein, to follow industry standard and common sense safety procedures when using the information contained herein and those using the information contained herein agree to defend and hold Pleasurecraft Engine Group harmless in all cases where injury and/or damage may occur during the use and/or application of the information contained herein.
DR

0-4 Degrees
Original Spec Decal
R143170B
Engine Serial Numbers
470001 - 485993 *** CAM Retard 0-4 Degrees
Updated Spec Decal
R143170B-U
Engine Serial Numbers
470001 - 485993 *** CAM Retard 6-8 Degrees
6-8 Degrees
Current Spec Decal R143170C Engine Serial Numbers
485994 - present
*** CAM Retard 15 +/- 2 Degrees
R143170B-U B

[jpwhit]

When I changed the TCP and reflashed ECM on the EX343 in my 200, I didn’t reset the CAM retard angle. It’s been running great. How long since you’ve done cap, rotor, wires, and plugs? If it’s been more than a few 100 hours, I’d start with cap and rotor before doing anything else.

[Spud]

Thanks jpwhit. Less than a hundred hours on cap and rotor aesthetics was changed when we were chasing the failing potentiometer…. I guess my question is if the ECM controls the timing could this have been adjusted back to the timing of the non effected engines as per the service bulletin?

[jpwhit]

To change the Cam Retard angle you physically rotate the distributor. If you didn’t move the distributor, then the Cam retard angle didn’t change.

[jpwhit]

Was thinking about your question some more, but also thinking about why a certain range of engine serial numbers would need a different Cam Retard Angle setting. Honestly that's a little baffling.

Then it occurred to me that there is the physical retard angle as set by the mechanical gearing in the engine between the crank, piston TDC, cam, and distributor position. And then there is the retard angle as computed by the ECM and reported to Diacom to aid in setting the physical retard angle. Maybe on the effected range of engines, the ECM was computing the reported retard angle incorrectly by a predictable shifted amount. An easy way to fix that would be to just change the recommended setting such that the physical retard angle was correct.

So it may be the case that with the new ECM firmware that you do indeed need to go back to pre-service bulletin Cam Retard Angle spec. At least as reported by the ECM. But this would only explain the problem you're having now if someone re-adjusted the CAM retard angle since the ECM was flashed, and did actually physically move the distributor.

[Spud]

So I know that the Cam retard (before the potentiometer fail and reflash ) was set in the 6-8 degree range as described in the service bulletin.

No one has touched the boat or motor to change the Cam retard value. I installed Potentiometer and the reflashed ECM.

Could it be possible that the ‘tune’ in the reflashed ECM needs to Cam retard set between 0-4 degrees as per all engines NOT originally covered by the service bulletin?

[jpwhit]

I can’t come with a good rational why that would be the case. But I think you should ask PCM that question.

The other option would be to mark the base of the distributor with a reference mark for the current position. Then you can try moving it a few degrees either way and see how that effects your roughness.

It’s also possible to set the cam retard angle mechanically/manually without Diacom. But it’s really a pain to do partly because you can’t see the rotor position through the distributor cap. It would be great if someone made a clear cap with reference marking for this purpose. And you also would have to manually rotate the engine to get number 1 cylinder accurately at TDC on the compression stroke.

[mlange]

When I replaced my TCP PCM provided the wrong flash and it stumbled and wouldn't run up to speed. May want to just do a quick check with them and make sure you got the right one.

[Spud]

So still chasing this as I am awaiting Diacom or tech mate to check cam retard..

For giggles I took the boat out again today just in case ( hoping ) that the new TPS and Ecm reflash just might need a few restarts a bit of idling around etc so the ECM can learn / adjust to the new TPS.

No luck still starts and runs beautiful up to 8 mph. Unfortunately from 8 up to 22 mph it misses stutters and backfires occasionally after 22mph it smooths put and seems to run very sweetly no detectable misses or stutters.

After taking the boat off the water I took the distributor cap off and took these pics….

Feedback thoughts etc appreciated

[Spud]

We have a resolution ( at this point in time ) got a hold of the tech guys at PCM and asked them about Cam Retard after my ECM re-flash. They advised to set it at 15 degrees as opposed to either O-4 degrees as per timing decal on engine or the 6-8 degrees as per PCM service bulletin SUP2009-01.

Boat on water Diacom plugged in, took engine up to 1200rpm loosened distributor hold down bolt rotated distributor to the advised 15 degrees and re-tightened hold down bolt.
Across the whole rev range the boat once again performs as it should, no hesitation , no misses and no backfiring. Starts and idles perfectly reaches WOT etc etc so very happy at this point in time that we have this issue sorted.

Another upside is I am know the happy owner of complete kit of Diacom diagnostics cables ( and software ) to work on any inboard EFI system.

[MN Ryan]

That's great news!

[billywro]

Great info, thanks for sharing. I have an Excalibur 343 with serial number 4735## (in the range) and also had my ECM re-flashed this summer. I had similar miss-fire/hesitation in the mid-RPM ranges but hadn't thought about cam retard angle as a culprit. Boat is winterized now, but will remember this in the spring.

[Spud]

Its definitely worth checking with a Diacom.. the 15 degree setting as advised by PCM for my re flashed engine is mentioned no where else that I could find.

Have had the boat out several times here in Australia since changing the Cam Retard and everyone mentions how well the boat is running!