AQ131D Timing Question

[rdengil1]

I have the AQ131D, have had nothing but problems trying to set the timing after the head was rebuilt. I added a rebuilt carb as well.

I aligned the timing marks as follows: Cam dot on pulley to the notch in the plate attached to the valve cover.

The crank sprocket (small gear that the timing belt goes on) I aligned with the notch on the gear to the mark on the plate attached to the block.

Intermediate gear, I aligned the dot on the gear to the notch on the plate attached to the side of the block by the alternator.

the belt was then aligned with the double line on the crank gear, the single line then lined up on the intermediate gear dot and the other single line led to the cam gear dot.

Then after putting the parts all back on the engine and placing the harmonic balancer pulley on the crankshaft gear, the mark on the pulley lined up under the 10 degree mark on the timing cover that the seawater pump attaches to. This is the one that starts at zero and goes up to 40.

I cannot get the boat to turn over and stay running, it seems like it is still off. I pulled the dist. rotated it so the rotor faced the #1 cylinder and corresponded to the #1 wire on the cap, then 1, 3, 4, 2. I ensured that I was a the end of the compression stroke for #1 cylinder. Does the harmonic balancer mark need to be moved back to zero once the timing belt is aligned? and then the timing set from there? I am assuming that the engine at idle should be at 6 degrees BTDC, which to me means that the mark on the balancer should indicate 6 degrees when the timing light is on it. I am just frustrated with trying to get this right. Should I also pull the electronic ignition out that I put in and go back to points? I was told that this could also be my problem because the electronic ignition could set the timing off by as much as 30 degrees. Thanks. Dennis

 

[Bondo]

Re: AQ131D Timing Question

Ayuh,.... I don't work on yer motor,...
But,...
Yer confusing, 'n combining the Cam timing, with the Ignition timing...
Both vitally Important, but Both are completely independent of each other....

 

[rdengil1]

Re: AQ131D Timing Question

I need help getting unconfused. If I set all marks correctly, then I should be able to move to ignition timing which I think is my issue. Someone said to forget the cam timing if it is done...set it and forget it. so with that said, he told me to line up the #1 piston at TDC on the compression stroke and remove the dist. then rotate the harmonic balancer until the mark on the pulley lines up at zero. Then put the dist back in rotating the rotor to the #1 piston, then install the cap and place the #1 wire where the rotor points at #1 piston. then 3,4,2. then fire up the engine and adjust w/ timing light. Didn't work....

 

[Bondo]

Re: AQ131D Timing Question

he told me to line up the #1 piston at TDC on the compression stroke and remove the dist. then rotate the harmonic balancer until the mark on the pulley lines up at zero.

Ayuh,... If the cam timing is Done, it's Done....

Bring the motor to TDC, #1.....
Then stab the distributer....

When ya get the motor to TDC, #1, the timing mark, aka; Ignition timing mark, Will be at 0?.....

 

[rdengil1]

Re: AQ131D Timing Question

I am assuming the ignition timing mark you are referring to is the mark on the harmonic balancer which the mark will then correspond to the zero on the timing cover once at TDC? this should, from what I am told and have read also be at the end of the compression stroke? Thanks. Dennis

 

[RogersJetboat454]

Re: AQ131D Timing Question

I am assuming the ignition timing mark you are referring to is the mark on the harmonic balancer which the mark will then correspond to the zero on the timing cover once at TDC? this should, from what I am told and have read also be at the end of the compression stroke? Thanks. Dennis

That is correct. That timing mark will line up at both #1 compression and exhaust TDC

 

[rdengil1]

Re: AQ131D Timing Question

How dumb is dumb? Well drained entire fuel system refilled and reset cam and then ignition timing. Started right up idle is high. About 2000 rpm. Checked with light. It was at 40? turned the dist mark moved to 20? then stalled. Should I adjust idle then rotate dis? Ran smooth and sounded great. But I still think I am off. The fuel was probably my issue. Almost there I think

 

[billbayliner]

Re: AQ131D Timing Question

Roger is right. TDC comes around twice and can get us in trouble when indexing. But when you strobe timing marks via #1 cylinder, the light will be reading the marks during the last range of the compression stroke ONLY. So if the distributor is phased right, its pretty much goof proof in that regard.


Copy and paste from a good source

Volvo Penta OHC 4 cylinder engine camshaft and countershaft drive belt indexing.

The belt cogs and pulley indexing dowels or pins must all line up! If these align the TDC pulley mark relative to the aluminum cover should be correct.

The counter shaft drives sea water pump, the distributor gear, cams the fuel pump lever, and turns the oil pump only.
The sea water pump, fuel pump and oil pump don't actually care how the counter shaft is indexed.


The reason for the counter shaft indexing is to phase the distributor and counter shaft gears. There seems to be one gear position that works better than another to bring the rotor towards #1 and work with the limited adjustment slot in the distributor housing.
I don't believe that it's absolutely necessary to be indexed this way, as long the firing order is correct, and you can make the timing adjustment. However, best to use the OEM procedure, IMO.

If you have the Pertronix kit, the sensor unit needs to be at the right height for the magnetic wheel.
There should be a shim or two in the kit. If these are off a bit, it can affect the triggering, and you may not get a consistent spark.

As for ignition timing, see your OEM manual for both BASE/Initial and Total Advance.
The numbers at the aluminum cover will show 0 to 40 degrees I believe.
Start by adjusting and setting BASE advance, and then check the much more important TA (total advance) numbers.
You'll be using these numbers while strobing with your timing light and while watching the progressive advance as you increase RPM to the limit RPM.
This limit will be where the progressive advance discontinues.
Again, see your OEM manual for this spec and make sure that your system offers the correct numbers per engine RPM.

Too little TA, and you'll leave power on the table.
Too much TA, and you'll risk Detonation and engine damage.

 

[rdengil1]

Re: AQ131D Timing Question

Thanks for the help on this. I have aligned all the marks on the cam, crank and the countershaft to the marks on engine. I also ensured the belt markings lined up on the dots on the gears. I then assembled the rest of the engine. When the aluminum cover is placed on the engine and the crankshaft drive pulley is attached and locked in position, the timing mark does not correspond to zero but rather ten degrees. What I did at this point was removed the distributor and rotated the crank clockwise to zero (I had the number one plug out and inserted the compression gauge in place and once the pressure began to build I watched the mark on the pulley until it reached zero and stopped.) then reinserted the distributor with the rotor pointing to the number one cylinder. I had the cap off and ensured that the rotor was pointing at the post on the cap and then put the number one wire there and reinstalled all the other wires. I'm not sure I am understanding exactly what I am doing which could be why I am struggling with this. Really need layman's terms. I think I will try again today and see if it fires and stays running.

 

[dennis461]

Re: AQ131D Timing Question

See if this picture helps...

http://www.threefattigers.com/Protocore/Volvo/TimingMarks.jpg

 

[rdengil1]

Re: AQ131D Timing Question

I learned that the crank pulley that has the ignition timing mark on it can sometimes slip due to the rubber doughnut that bonds them. So I bought a new pulley and checked the marks with them laying on top of each. marks were spot on. So returning the pulley. New question with regards to the timing issue.

What I don't understand is that the workshop manual states to align all the marks for the toothbelt installation, which I have done numerous times. Then later in part 5c para. 295 it states the following:
Turn the crankshaft to the firing position for number 1 cylinder. Check to make sure that the camshaft cams for number 1cylinder are pointing away from each other and that the pulley marking is indicating ?0?. Put on a new gasket and install the valve cover and the plate for the belt marking. Make sure that the belt marking coincides with the recess of the
plate. Adjust if necessary. Then put the dist. in. (properly aligning the rotor to #1)

My problem is that when I put all the marks lined up, the pulley is at 10 degrees when I install the timing cover. I bought a brand new pulley, not used, and it lined up the same. Am I missing something here? This is the question I haven't had answered and cannot find anywhere. When the gears are all in alignment, I thought his should be TDC indicating 0 degrees, am I wrong? I linef up the cam, crank and intermediate gears to the respective marks and then the belt with its corresponding marks, once that was done the pulley will only lock in one way and the mark indicates 10 degrees.

Should I line up cam and intermediate and the move the crank pulley to zero by the pulley and not the gear and then install the belt? I am about to give this up. the only way the boat will stay running is if it is at about 2000-2500 rpm at 15-20 degrees advance. once I dial it back to try and get the pulley mark to hit 6 degrees it immeidately dies. I have been over and over all the advice and through both the seloc manual and the workshop manual and have had no luck. Anyone want to come to va beach for a beer? Ugh

 

[Don S]

Re: AQ131D Timing Question

Once you install the belt, Turn the engine in normal direction of rotation, 2 complete revolutions and put the timing marks on the crankshaft a TDC, now look at the round dot on the cam wheel, not the painted line on the belt, the dot should be lined up and the cam in the correct position.

 

[Mullin]

Re: AQ131D Timing Question

Do it like Don says. Once the belt is on the marks on the belt don't mean anything and will not line up again. They are just there to help you get the belt on tight.

Belt on, rotate it twice, cam and crank at zero, adjust the tension, stab the dist pointing at #1.

I just finished putting in a hot spark ignition kit today and had similar symptoms. Ran at a higher rpm, advance was at like 30 or so. Slowed down the idle with the idle screw and that helped bring the advance back a little, then twisted the dist to get it on 10 degrees while readjusting the idle to 750rpm.
Double checked 4200rpm advance was at 36 degrees and was good to go.

This is on my aq125a, very similar.

*Edit*

About 2000 rpm. Checked with light. It was at 40? turned the dist mark moved to 20? then stalled

Just a FYI, After setting my timing I went and bumped the rpms to 2000 and checked the advance, it is at about 24 degrees at that rpm.