1986 460 Smog Pump Delete

[ArdWrknTrk]

To remove any doubt, I moved the bottom port of the vcv from the carb port to a port on the exhaust manifold tree. It seemed to run better there too. I marked the crank pully at 0, 10, 20, as best I could (i need to get a more visible marker) and with the timing gun set at 0 it was reading around 20, but looked like it was bouncing a little back and forth.

I ended up turning the dist vac advance with the Allen wrench all the way clockwise (is that fully closed?) And that was the best it ran. The 20 mark stabilized much better under the timing gun. I then adjusted the idle screw to get to 800 rpms. I did NOT remember to clamp the dist vac adv hose, per the ford instructions below during this process though, sadly. I'll have to try again, I assume. Here's the gauge after those adjustments:

22" hg is very good, but the timing marks bouncing around is not.

I'm going to suggest you check for chain slack in two ways.

1) with the timing light on and the vacuum advance capped or clamped with hemostats, rev the engine up slowly to see how much total mechanical advance you have (this is probably 3,000- 3,500rpm) then -while watching the timing marks let the throttle slam shut. Do the timing marks retreat smoothly? Or do they flail around while returning to your static mark of 10°?

2) get a 15/16 deep socket and a breaker bar or long ratchet. Remove the distributor cap so you can see the rotor.

Turn the crank counter clockwise so the rotor moves and the wrench is directly at 12 o'clock.

Then move the wrench clockwise until the rotor begins to change direction.

Where is the handle? 3 minutes? 5 minutes? 8 minutes???

This is going to give you a good idea how much wear or slacks you have.

Maybe Vivek can explain it better than me. 🤷‍♂️

[Bullnose Gator]

22" hg is very good, but the timing marks bouncing around is not.

I'm going to suggest you check for chain slack in two ways.

1) with the timing light on and the vacuum advance capped or clamped with hemostats, rev the engine up slowly to see how much total mechanical advance you have (this is probably 3,000- 3,500rpm) then -while watching the timing marks let the throttle slam shut. Do the timing marks retreat smoothly? Or do they flail around while returning to your static mark of 10°?

2) get a 15/16 deep socket and a breaker bar or long ratchet. Remove the distributor cap so you can see the rotor.

Turn the crank counter clockwise so the rotor moves and the wrench is directly at 12 o'clock.

Then move the wrench clockwise until the rotor begins to change direction.

Where is the handle? 3 minutes? 5 minutes? 8 minutes???

This is going to give you a good idea how much wear or slacks you have.

Maybe Vivek can explain it better than me. 🤷‍♂️

It stabilized at 20 in the end, but I'll need to look up some videos to see what "stable" truly looks like since I've never used a timing gun before.

Also, to clarify, I adjusted the CURB idle screw, not the idle mixture screws.

[viven44]

22" hg is very good, but the timing marks bouncing around is not.

I'm going to suggest you check for chain slack in two ways.

1) with the timing light on and the vacuum advance capped or clamped with hemostats, rev the engine up slowly to see how much total mechanical advance you have (this is probably 3,000- 3,500rpm) then -while watching the timing marks let the throttle slam shut. Do the timing marks retreat smoothly? Or do they flail around while returning to your static mark of 10°?

2) get a 15/16 deep socket and a breaker bar or long ratchet. Remove the distributor cap so you can see the rotor.

Turn the crank counter clockwise so the rotor moves and the wrench is directly at 12 o'clock.

Then move the wrench clockwise until the rotor begins to change direction.

Where is the handle? 3 minutes? 5 minutes? 8 minutes???

This is going to give you a good idea how much wear or slacks you have.

Maybe Vivek can explain it better than me. 🤷‍♂️

I like Jim's suggestions

When I attempted 2) in the past, I would turn the crank counter clockwise until the distributor rotor would start moving barely... read the degrees on the harmonic balancer... then turn the crank clockwise until the rotor starts moving the other way barely... and see how many degrees on the harmonic balancer that resulted in... I have seen that if that is 10 degrees = new timing set.

And don't forget to remove the wrench off the crank. I can't tell you how many times I left the damn thing on, and got lucky

Jeremy, your adjustment of the vacuum advance via the allen wrench all the way clockwise should result in more advance per the guide below that Jim sent, but listen for potential pinging. You don't want to overdo it for sure. Not sure why your distributor needed that adjustment.....

https://vb.foureyedpride.com/showthread.php?22229-The-Ultimate-Duraspark-Distributor-Timing-Guide

[ArdWrknTrk]

It stabilized at 20 in the end, but I'll need to look up some videos to see what "stable" truly looks like since I've never used a timing gun before.

Also, to clarify, I adjusted the CURB idle screw, not the idle mixture screws.

Right.

We are talking about two different things.

Idle mixture to achieve highest vacuum (then I usually open up 1/8-1/4 more. Better safe than sorry!)

Then you use the throttle stop (curb idle screw to adjust the engine speed.

Then you adjust the ignition timing (and back and forth if you need to reset the idle rpm)

Then you reconnect the vacuum advance and set the curb idle again.

Now we're where the compliance sticker tells us.

[Bullnose Gator]

22" hg is very good, but the timing marks bouncing around is not.

I'm going to suggest you check for chain slack in two ways.

1) with the timing light on and the vacuum advance capped or clamped with hemostats, rev the engine up slowly to see how much total mechanical advance you have (this is probably 3,000- 3,500rpm) then -while watching the timing marks let the throttle slam shut. Do the timing marks retreat smoothly? Or do they flail around while returning to your static mark of 10°?

2) get a 15/16 deep socket and a breaker bar or long ratchet. Remove the distributor cap so you can see the rotor.

Turn the crank counter clockwise so the rotor moves and the wrench is directly at 12 o'clock.

Then move the wrench clockwise until the rotor begins to change direction.

Where is the handle? 3 minutes? 5 minutes? 8 minutes???

This is going to give you a good idea how much wear or slacks you have.

Maybe Vivek can explain it better than me. 🤷‍♂️

So is 20 OK, even though the emissions set up originally called for 8? Seems like a big jump. It also seems to have a little more "chuggalug" to it than before as well.

[ArdWrknTrk]

So is 20 OK, even though the emissions set up originally called for 8? Seems like a big jump. It also seems to have a little more "chuggalug" to it than before as well.

20° BTDC is your static timing?

That seems WAY too much, and I'd expect the starter to labour, if it could spin the engine at all.

10 is fine, and 12° BTDC should be okay if the timing retard or your DS-II module is functioning .

[Bullnose Gator]

22" hg is very good, but the timing marks bouncing around is not.

I'm going to suggest you check for chain slack in two ways.

1) with the timing light on and the vacuum advance capped or clamped with hemostats, rev the engine up slowly to see how much total mechanical advance you have (this is probably 3,000- 3,500rpm) then -while watching the timing marks let the throttle slam shut. Do the timing marks retreat smoothly? Or do they flail around while returning to your static mark of 10°?

2) get a 15/16 deep socket and a breaker bar or long ratchet. Remove the distributor cap so you can see the rotor.

Turn the crank counter clockwise so the rotor moves and the wrench is directly at 12 o'clock.

Then move the wrench clockwise until the rotor begins to change direction.

Where is the handle? 3 minutes? 5 minutes? 8 minutes???

This is going to give you a good idea how much wear or slacks you have.

Maybe Vivek can explain it better than me. 🤷‍♂️

Static...BTDC....more terminology for me to look up. Lol

[viven44]

Static...BTDC....more terminology for me to look up. Lol

Yes that is too much timing. It might cold start without problems most of the time but re-starting when hot on a hot day might be impossible. I had that problem recently... even just running 10 BTC initial timing. I upped the battery size (With double the CCAs) and that seemed to have helped me deal with that. My old battery was probably junk too. The cheap load tester probably overstated its capabilities.

Jim, a local guy and I thought of an idea to deal with this problem... the starter can turn all day when this happens as long as there is no power to the DS-II/coil... how about a "spark switch" in the dash. The idea is to get the starter going, and when it is really going, you turn on the "spark switch" which finally sends power to the DS-II module. Also be a nice theft deterrent...

I think modern cars/trucks must have some spark-delay in place to deal with heat soak.... and why you crank for a few hundred milli seconds before the engine fires.

[Bullnose Gator]

Static...BTDC....more terminology for me to look up. Lol

So I need to adjust the distributor, or is this part of the recurving rebuild process to bring it back down?

[viven44]

So I need to adjust the distributor, or is this part of the recurving rebuild process to bring it back down?

Should be able to just loosen the 9/16th or 1/2 inch nut and turn the shaft of the distributor (I think counter clockwise) to bring back initial timing to 10 BTC.... you can make adjustments on the fly with a timing light before finding the sweet spot.

A set of these would be nice

https://www.autozone.com/wrenches-pliers-and-cutters/wrench-set/p/duralast-1-2in-and-9-16in-distributor-clamp-wrench-set-2-piece/914110_0_0?cmpid=LIA:US:EN:AD:NL:1000000:TLS:19489353547&&CATARGETID=120054150001289970&CADevice=c&gad_source=1&gclid=Cj0KCQjwwae1BhC_ARIsAK4Jfrx59Xvwja22YdtuPlKm_yWlHuweFFJMp7lNvXxkbrnpO5nC8npaDDkaAhANEALw_wcB&gclsrc=aw.ds