Timing Question / Feedback Request - 2002 Volvo Penta 5.7 GXi-C

[PcolaBeach]

Good morning all,

Subject engine recently had block replaced for a variety of reasons and I'm concerned the distributor installation might be off. The attached curve is of engine rpm's, check engine light, knock retard and spark advance. As the engine is first started and running, the spark advance is roughly +5 to 8 degrees ATDC. Upon the initial run up at around 3000 rpm the knock sensor picks up and retards the spark advance by -5 degrees (coincidental with the check engine light) from 32 to 27 degrees. Upon reducing the throttle to idle the timing is erratic between 0 and -5 degrees BTDC. Engine top RPM's are also limited to 4000 while 5000 is expected.

While I understand the timing is set by the ECM, I'm interested in feedback from others as to whether the values above are what you would expect? For some reason I'm unable to attach photos or files at this time.

Thank you!

The engine information:
Volvo Penta 5.7 GXi-C Raw Water Cooled
Serial Number 4012062213
Production Number 3869137
MEFI Assembly Number 57IAFM/02HT01 3861773
Boat - 2002 Cobalt 240

 

[alldodge]

Unable to say if its acting correctly, mine moves around a lot at idle. Getting a knock would most likely mean the timing is not correct

Was the distributor installed as shown?

 

[PcolaBeach]

We have not checked the distributor installation although initially the cam retard angle was found to be 62 degrees. Thank you for the instruction sheet. We did loosen the distributor and using the diagnostics software adjusted the cam retard setting from 62 to 45 degrees. Seemed like at 45 degrees, I was unable (not that I wanted to) to rotate the distributor any more. Like it was up against a stop?

The attached curve is of engine rpm's, check engine light, knock retard and spark advance. As the engine is first started and running, the spark advance is roughly +5 to 8 degrees ATDC. Upon the initial run up at around 3000 rpm the knock sensor picks up and retards the spark advance by -5 degrees (coincidental with the check engine light) from 32 to 27 degrees.

At 100% throttle the maximum engine speed is roughly 3950 rpm's. We were expecting more like 4800-5000.

 

[muc]

If you can adjust cam retard to 45°, the dist is in right. The dist has nothing to do with timing. The ECM uses the crank position sensor, temp, battery voltage, fuel octane and much more to set the timing. Only thing you can do turning the dist. is send the spark to the wrong cylinder

Check engine light on means you have an active code, what is the code being set?

Is the engine knocking? ECM can take out up to 10° of timing to remove the knock.
If the knock sensor wires are routed too close to secondary
ignition wires, the ECM may see the interference as
a knock signal, resulting in false timing retard.


What is the octane rating that is showing on your scan tool? This will affect what spark tables the ECM is using and give a better idea if your seeing the right amount of advance.

Are you checking advance with a timing light? It is normal for the timing to "dance" all over the place.

What is fuel pressure at 4000 rpm under load?

 

[PcolaBeach]

Thanks Muc for the feedback on the distributor being installed right if the cam retard can be adjusted from 62 to 45 degrees.

Looking back over the scan log, I didn't notice it before but sure enough, the check engine light does come in at the same time DTC 44-2-L first appears. The check engine light also coincided with the knock retard and spark advance correcting by 5 degrees so I suppose I got too focused on that. We've not been too worried about DTC 44-2 codes in that this engine only has one knock sensor and DTC 44-1 would apply. It's my understanding DTC 44-2 codes are for 6.0/8.1L engines only.

The octane rating that appears on the scan tool is 99.6.

Given the exhaust level noise, it's just too hard to tell whether the engine is knocking at 3000 rpm's.

We're only checking timing with the diagnostics monitor and not checking the timing with a timing light. The spark arrestor appears to be pretty clogged up. There are some other maintenance items to be addressed as well. Depending on the next test run, we might be getting some gauges on the fuel system to test pressures.

Thanks again!

 

[muc]

You need to pay attention to any codes on a Volvo. Check the wire harness, it’s possible there is a wire for a second knock sensor.
But a code 44 is only for a open circuit on the knock sensor. The engine knocking doesn’t set a code on MEFI 4

 

[muc]

With a octane rating of 99% you are using the best spark table. The loss of 5 degrees timing isn’t what is loosing the 1000 rpm.

 

[PcolaBeach]

Thanks Muc. This will likely be the last post on the subject. Once some of the other maintenance items have been addressed there will be a follow up test run in an attempt to get above 4000 rpm. If there are still issues, I'll begin a new thread.

Code 44-2 is present from the time the engine is started. Code 44-2-L comes in later at the 3000 rpm speed. Turns out there are two other codes that come and go almost instantly while the engine was at 3950 rpm's. They are 31-L and 81-18-L, neither of which I can find any information on. Each code clears up on it's own and didn't appear again throughout the test run.

Thanks again!

 

[muc]

Not sure whats going on here. Never used the software you have. Is it possible that you have selected the wrong engine? I ask because there is no code 31 listed for your engine, also code 81 has 10 possible causes. So have no idea what 18 could mean.
Next, the knock system only becomes active once the engine has reached a certain temp and RPM, So you shouldn't see a code 44 at startup.
DTC 44 will set only if the ECM does not see
any activity on the KS signal circuit(s).

Maybe contact the software provider and ask whats wrong?

 

[alldodge]

Just a thought and don't know about VP and MEFI4, but with a Merc and MEFI3 code 44 is set if the knock sensor is not found on first throttle up. My understanding is on first throttle up the ECM tries to advance timing far enough to get a knock sensor to signal. If it gets the signal code 44 is not set and timing is adjust according to the tables.

Had this issue with my motor and running 93 octane (need 89 to 91), the ECM could not get it to knock. Since then I have disabled code 44

 

[muc]

Just a thought and don't know about VP and MEFI4, but with a Merc and MEFI3 code 44 is set if the knock sensor is not found on first throttle up. My understanding is on first throttle up the ECM tries to advance timing far enough to get a knock sensor to signal. If it gets the signal code 44 is not set and timing is adjust according to the tables.

Had this issue with my motor and running 93 octane (need 89 to 91), the ECM could not get it to knock. Since then I have disabled code 44

Volvo never used the “self spark sensor system test” that MerCruiser used. Also MerCruiser only used this for a very short time on the MEFI 1 ECM. By August 1994 they removed that feature. It was a code 43 that was set. MCM 94-12

alldodge If you were getting a code 44 on a MEFI 3 ------ 93 octane wasn't your problem.

This is why serial number can be so important. Not only is there a difference between Volvo and MerCruiser in what program is in the ECM. There is also a difference between MEFI 1-2-3-4-4a-4b

 

[Finseeker 268]

Thanks Muc. This will likely be the last post on the subject. Once some of the other maintenance items have been addressed there will be a follow up test run in an attempt to get above 4000 rpm. If there are still issues, I'll begin a new thread.

Code 44-2 is present from the time the engine is started. Code 44-2-L comes in later at the 3000 rpm speed. Turns out there are two other codes that come and go almost instantly while the engine was at 3950 rpm's. They are 31-L and 81-18-L, neither of which I can find any information on. Each code clears up on it's own and didn't appear again throughout the test run.

Thanks again!

Did you ever resolve this issue? I have a 5.7 GXI and it won't go over 3600 RPM.