Advice on engine timing (2 Viewers)

[Hammer45]

Hello again. I recently installed a Man_A_Fre reman high performance 3Fe engine (Rebuilt High Compression 3FE Long Block Engine for 1987-1992 Toyota Land Cruisers - Landcruiser Parts - https://manafrelv.com/product/rebuilt-high-compression-3fe-long-block-engine-for-1987-1992-toyota-land-cruisers/) as well as well as @cruisermatt new H55 and new transfer with the 5th gear. It was a challenging and rewarding project for a first timer. Couldn’t have done it without MUD members. Many thanks for your patience with my stupid questions! It has been running fine for about a week of driving but I had never set the timing with the timing light as we had a trip to Germany set in stone. I just now did the timing to 7 degrees BTDC and it is running kinda rough at idle. It was not before when by ear I had it set to about 30 degrees. Only discovered it was this far out when I went looking for the hole on the flywheel and had to adjust the dial on the light to 30 degrees. This engine requires premium gas per Man_A_Fre. Any tips on timing with the higher octane fuel? I am desmogged as well.

 

[bhsdriller]

Manfre built it what have they said

 

[Pighead]

I don't know about a 3fe, but my 2F likes a lot more advance than the FSMs 7*. When I time by manifold vacuum I get around 25* BTDC, I turn it down to 22* for around town. Put a vacuum gauge on the intake manifold and see if it agrees with your ear

 

[Hammer45]

I don't know about a 3fe, but my 2F likes a lot more advance than the FSMs 7*. When I time by manifold vacuum I get around 25* BTDC, I turn it down to 22* for around town. Put a vacuum gauge on the intake manifold and see if it agrees with your ear

Thanks for the suggestions.

 

[Hammer45]

I don't know about a 3fe, but my 2F likes a lot more advance than the FSMs 7*. When I time by manifold vacuum I get around 25* BTDC, I turn it down to 22* for around town. Put a vacuum gauge on the intake manifold and see if it agrees with your ear

Im looking for the highest vacuum correct? I have never used the vacuum method to set timing. I assume it’s the greatest power output causing the highest vacuum output due to proper timing of the firing, correct?

 

[mattressking]

I don't know about a 3fe, but my 2F likes a lot more advance than the FSMs 7*. When I time by manifold vacuum I get around 25* BTDC, I turn it down to 22* for around town. Put a vacuum gauge on the intake manifold and see if it agrees with your ear

Because you have vacuum issues most likely. These run great at 7, advancing masks your vacuum leaks.

 

[mattressking]

Im looking for the highest vacuum correct? I have never used the vacuum method to set timing. I assume it’s the greatest power output causing the highest vacuum output due to proper timing of the firing, correct?

Vacuum is what the engine pulls when the pistons cycle, between that action and the movement of the throttle plate is where air is metered and if there are leaks, air/fuel mixture is affected negatively.

So set base timing, ensure valves are correct, then measure vacuum at idle, with all accessories off and idle speed under 950rpms. Since this is a 3FE, vacuum is 'less' important because the motor can compensate for air leaks by adding/removing fuel to a point to aid the metered air leak.

 

[Hammer45]

Because you have vacuum issues most likely. These run great at 7, advancing masks your vacuum leaks.

I suspect that’s possible but I’ve capped all the lines and have all new tubing. I can recheck.

 

[Pighead]

I suspect that’s possible but I’ve capped all the lines and have all new tubing. I can recheck.

Think he's talking to me...

 

[mattressking]

Think he's talking to me...

Ha yea, failed to plug in quotes....too many tasks in front of me.

 

[Hammer45]

Manfre built it what have they said

Rick at Manafre suggested factory settings and wondered if the desmog might be affecting the airflow a bit. Again, it has lots of power and even going up an incline in a higher gear, I get no pinging.

 

[1911]

I don't know about a 3fe, but my 2F likes a lot more advance than the FSMs 7*. When I time by manifold vacuum I get around 25* BTDC, I turn it down to 22* for around town. Put a vacuum gauge on the intake manifold and see if it agrees with your ear

This.

Start at 7* BTDC if you want, then advance it as far as it will go without knocking or pinging under load. When you get to knocking or pinging a little bit, then back it off until it doesn't. Takes a few times of trial and error but worth it.

 

[Spike Strip]

I have a MAF 2F but normal or slightly raised compression so I can run reg 87 gasoline. I'm at 9* BTDC.

Sure your dissy isn't a tooth off?

 

[Godwin]

We run our desmogged 3FE at 9-10 degrees advanced and it runs good.

 

[Hammer45]

I have a MAF 2F but normal or slightly raised compression so I can run reg 87 gasoline. I'm at 9* BTDC.

Sure your dissy isn't a tooth off?

Good question. I redid it 3-4 times as the rotor was pointing in the wrong direction afterward. the last time it was right at uh was it the #4 spark plug? I don’t recall but it was pointing where it was supposed to be and I get to 7 degrees pretty easily in the slotted movement of the dizzy. Seems like people on mud complain when they can’t get to 7* no matter the rotation and that’s when it seems to be off a tooth. I could easily be wrong.

 

[Hammer45]

This.

Start at 7* BTDC if you want, then advance it as far as it will go without knocking or pinging under load. When you get to knocking or pinging a little bit, then back it off until it doesn't. Takes a few times of trial and error but worth it.

Yeah that’s my plan tomorrow. I feel more comfortable about easing up or actually down after reading the input from everyone. All of this is really pretty minor as it doesn’t die and has lots of get up and go so I don’t think it will require much. I am intrigued by the vacuum method and will add that as well. Thanks! I’ll post a follow up in a day or two for completeness.

 

[Spike Strip]

If it doesn't take much twist of the dissy to get to the 7 degrees, then you're probably good. The poor idle is then something else

 

[Godwin]

Running rough at idle, check your intake hoses, the ones between the air filter housing and throttle body to make sure that they are in good condition. With age these will commonly crack leading to poor idle on a 3FE.

 

[Hammer45]

Running rough at idle, check your intake hoses, the ones between the air filter housing and throttle body to make sure that they are in good condition. With age these will commonly crack leading to poor idle on a 3FE.

Yessir. Brand new 2 yrs ago but I’ll recheck. I’ll recheck those vacuum hose attachments on the back of he breaher