Setting timing on ford 460 / Winnebago
 

I have a 1987 Winnie with ford 460 with holley 4 barrel. I have done a lot of work on it to fix various issues.

This thing has been getting lousy gas mileage for some time. I have checked all vacuum issues. Compression is good. manifolds are tight.

After running for 10 miles or so and the engine gets good and hot, it dies when I pull off the highway. Somebody thought it was vapor lock but I can't imagine this could be the case because the metal fuel line is insulated and double gaskets under the holley for insulation and better fuel dispersion.

The pickup, Motorcraft ignition module, coil, spark cables replaced. New copper plugs set to .044.

I have seen other postings here on setting timing on this era 460, but mine does not match the hardware.

My distributor does not have the little rectangular solid state module at the base of the distrib (I think this is the SPOUT often referred to elsewhere in this forum). If the SPOUT is not that rectangular thing on the side of the distributor, where is it and what does it look like? My distributor is the tall/large diameter one, not the short one. The distrib has vac advance air motor and pickup in the distrib housing wired back to a motorcraft ignition module.

I replaced the motorcraft, even tho it checked out OK at the auto parts store.

One thing that bothers me: I don't see a resistor anyplace, but the coil says it requires one. This vehicle has never had one. Is it inside the ignition module?

Another thing that bothers me: the ignition coil gets pretty hot just sitting there with the ignition on but engine not running. This holds true for both the old and new ignition coil. It this normal?

Since I don't have a SPOUT, is there anything I should disconnect for setting the timing besides the vac advance hose? Or should I disconnect one of the connectors from the ignition module (there is a 4 pin and a 2 or 3-pin connector).

My engine says to set timing at 8btdc, but I see lots of folks saying 10-14. Mine was set at 14 last time I set it, I put it at 8. I'm assuming that timing should be set at about 600 rpm normal idle.

Any tips would be muchly appreciated

You might try in the 1987-1996 forum Here the vac advance hose is removed from the dist and plugged. The ign module has the resistor circuit built in. But for a '87 I don't know.... Just be guessing.

More info
 

Something weird.

I have lines painted on the flywheel at 8 and 12 btdc. Looking from the rear of the motor (as you would see working on an RV with doghouse), the vac advance nipple is pointed roughly at 54 minutes (as on a clock). With the timing light I see it about halfway between the flywheel marks. But the engine dies and backfires if I put enough gas on it to keep it running.

If I turn the dist. clockwise so the vac advance is more near 12:00 (advancing it a lot), it runs better, but the marks are so far off the pointer I can hardly see them (I am using an inspection mirror from underneath the rig to see the timing marks).

Something is way off here.

With the cap off, I can turn the rotor a few degrees CCW and it returns via spring. I think that is normal. It tried this with both the original and the new ignition modules with no difference. I double checked spark plug cables, they are all connected correctly
1-4 down passenger side, 5-8 down driver side, connected in firing order 1 - 5 - 4 - 2 - 6 - 3 - 7 - 8 to the cap.

I'm wondering if the gear is shot on the distrib and it slipped a notch? I set the timing last year at "factory" 8 btdc and everything seemed ok then, but the engine never ran good. It was at 14btdc before and it had lousy gas mileage.

But now it does'nt like it when the marks are anywhere near the pointer. The engine is not that old, about 25k miles on it, a rebuild.

Any ideas?

Could the rubber be a bad on the harmonic balancer giving you a false reading on the timing marks? I have an 86 Winnie with a 454 and only get 8-10 MPG, that's normal for our older rigs.

I checked the balancer and read some of the horror stories about these things walking off. I think the balancer is probably ok. The rubber is all there. I don't see evidence that it is moving forward/backwards. I could not move it by hand, and I tried real hard. I put some marks on it so I can see if it is rotating. will test again tomorrow.

I worked some more with it today. If I set it to anywhere between 8-12 btdc, it wont run unless the gas pedal is way down. It backfires with the gas down. The nipple for the vac advance is at about 11:00 when btdc is between 8-12.

I have a good innova timing light with long leads. I'm seeing a steady spark on the #1 lead (was not seeing that before I put in the new pickup).

I gave up on the timing lite to try setting it by feel (easy to do in an RV with the cap right next to my foot).

It idles with the vac advance nipple a bit to the right of 12:00, with good vacuum about 18-20 with the nipple at 12:30. I can rev it pretty good. then it dies after about a minute. But it does not start easily. when starting the engine nearly stops as if it is trying to fire the engine the other direction.

Something is really messed up here. I have timed engines before, this is something entirely bizarre. Is it possible that the gear driving the distributor is shot and jerking, slipped a notch, or something?.

so, did you figure out that the timing is set with the vacuum disconnected from the vacuum advance and plugged? you set it at xx, then reconnect the vacuum. it will advance to around 20 at idle, that's normal. Then you take it up to 3500 rpm. and set max advance again by puttin the light on it and setting at 30-35. There are some dumsh1ts on the boards here saying it should be 14 or so with vacuum connected- BS!. Initial timing is always set with vacum disconnected and plugged. Also, ignore anyone talking about ported vs manifold. always use manifold.

Is there or was there an EGR valve on the motor ? Have you had the distributor out ?

All initial timing is set from TDC and the only bullet proof way to determine TDC is with a piston stop .. Summit has them for about $8.00 .. The thread size will be the same as your spark plugs ..
https://www.ford-trucks.com/forums/d...AREQEREBERA//Z

1) Remove one end of the coil wire
2) Remove #1 plug
3) Place your finger over the #1 spark plug hole and have someone rotate the crank shaft until you begin to feel the compression trying to blow your finger away from the hole .. The rotation of the crankshaft will be easiest with all spark plugs removed .. your call
4) Thread in the piston stop
5) gently rotate the crank shaft until the piston hits the piston stop
5) make a distinct mark on the harmonic balancer at this point
6) rotate the crank shaft now in the opposite direction until you are stopped by the piston stop
7) mark the harmonic balancer again at this point
8) TDC will be the center point between these two marks scribe this point well .. All future timing will be set from that mark
9) remove the stop and reinstall the spark plug/plugs and reconnect the wire/wires
10) rotate the crank to your 8* BTDC if that's where it is supposed to be
11) take off the distributor cap and determine if the rotor is pointing at the #1 contact on the distributor cap .. If it is then your good .. If not go to the next step
12) take out the distributor hold down bolt and clamp
13) carefully pull the distributor up far enough that the rotor now spins freely and being careful not to dislodge the oil pump shaft ..
14) Now rotate the rotor so it points to #1 after distributor is reinserted .. This may take a few tries to get it right ..
15) Once you have it put the Hold down clamp and bolt back in place
16) Reconnect your coil wire
17) Now you can start the motor and check timing with the vacuum line to the vacuum advance disconnected and plugged ..

Note : If the vehicle is equipped with an automatic transmission the idle rpms should be set with it in gear and brake on ..

Red,

Good reminder on disconnecting and plugging the vacum line, I've seen a few posts here saying not to do it. My 76 says 12btdc. When I disconnect the line, plug it, set timing, then hook it back up, the timing goes to around 18 btdc after hooking back up to the advance. Is this normal?

question - idle set in gear with brake on- makes sense, but doesn't that end up with super high idle speed when truck is in park/nuetral ?

There should be no timing advance by vacuum source @ idle ..

The correct curb idle speed will be lower for an automatic for that reason .. It is done this way so when you put the vehicle in drive it doesn't immediately stall out .. The difference is usually about 150 rpm

Have a look here 77 and 78

Thanks- helpful. 150 rpm is no big deal,

so if there should be no vacum at idle, and my timing is kicking up from 12btdc to 18/20 after hooking the line, I have vacum. so, than means my carb is set too rich, or my guesstimate of idle speed is too high I guess

I set the timing, adjusted the carb using my vacum guage- taking it one side at a time, going rich until it maxed then declined, then backed off 1/4 turn. Still flunks emissions with high HC & lousy power. All my ignition system is redone & checks out. stock duraspark

Which module are you using for your Duraspark II ? What color is the strain relief for the wires coming out of the module ?

Blue one.

fixed a vacum leak earlier today. Now when I set initial timing at 12btc, and reconnect the vacum, it goes to 26! I'm using manifold vacum. I makes sense timing would advance, as vacum is max at idle , no? butterflys are closed, so should be more. when throttle is opened vacum decreases, then the mechanical advance kicks in. Dern advance can on the cardon distributor is not adjustable :(

Like I said before The vacuum advance shouldn't influence the timing until maybe 300 - 500 rpm off idle .. Try ported vacuum off the carb ..

A vacuum advance canister provides a way to advance the ignition timing during moderate and part throttle conditions. This is when the load on the engine is less and vacuum is higher.

thanks. I moved the vacuum line from the right side of the edelbrock (manifold), to the left (ported)- funny thing is that there was vacuum on both sides at idle. So, hooked up the vacuum gauge and lowered the idle (ignoring the tach), until vacuum was 0, then set timing.

Pretty much at a loss now. Set timing at 12btdc again with vacuum disconnected and plugged. Set carb mixture using my vacuum gauge on manifold vacuum by taking each side down to fully lean then turning out till max vacuum. Sprayed ether all over the intake and vacuum lines and no vacuum leaks anywhere. Ignition system seems fine- no pings, no backfires, spark at every plug.

Runs a bit better, but still lacks any neck slapping or boat towing ability. It had more "umph" power before my upgrade to edelbrock 600 and weiand stealth manifold- with the motorcraft carb and stock manifold. And, it passed emissions with that set up. this dog won't - I did something but can't figure it out.

Still no guts, shakes on initial acceleration, and no tourqe when crusing. Just replacing parts is for dumsh1ts. Problem is that the definition of insanity is doing the same thing over and over and thinking you'll get a different result & by redoing timing and carb over and over I'm not getting anywhere. Changed fuel filter for the heck of it.

1- I did have some backfiring previously, with some flames lingering. Could that have shot my acceleration pump?
2. should I consider using the edelbrock tuning kit and changing the jets/metering valves to something smaller (this thing has high HC and CO under load on emissions testing, and high HC at idle)- maybe bad acceleration is from too rich/bogging?
3. no difference in performance with Air cleaner on/off, so doesn't seem to be restricted air flow

any comments appreciated