Timing, timing, timing

[LD3]

Hey everyone,

I posted months ago regarding getting more power viewtopic.php?f=2&t=11432. I worked on a few things and then parked the car without much success.

Anyway, after going back and re-reading my last post/replies and reading up on a similar situation Mark had, I am pretty certain my timing was off. viewtopic.php?t=9103

When I went back to the car this afternoon, it was reading 7 degree (I should mention I used a different timing light this time) and I was getting next to no power (the car would rev high/quick in neutral but could barely drive on flat ground once in gear). I decided to increase the timing just to see what happened and set it to 12 degrees. Right away I noticed a huge improvement in power. However, when I went to turn the car off there was a little bit of "dieseling." Does this mean the timing was too low below top dead center? Is it okay to drive like this or will it damage the engine over time?

Thanks

[atoyta]

I would retard the timing until the dieseling is gone. It will also tend to detonate when it is too advanced.

[irowiki]

My 87 diesels because the carb is bad, independent of the timing, I've found.

[Mark]

I recommend setting the timing manually as described in the following guide:viewtopic.php?f=7&t=5216. Set it somewhere between 5 and 10 degrees. Disregard what the timing light is showing you for now and see how the power is.

[dlb]

I would retard the timing until the dieseling is gone. It will also tend to detonate when it is too advanced.

ditto.

if the car barely moves with the timing at 7* BTDC, i don't think timing is the problem. something else is going on. if the car has been sitting, is the park brake stuck? adequate fuel and spark? could be a number of things so you have some investigating to do.

dylan (the former owner) replaced the fuel filter about a year ago but at $5 for a filter, it might not be a bad idea to replace it again.

btw, very glad to hear you're back at this again, luke!

[Mark]

I suggested manually setting the timing since in my case, I had a hell of a time using a light to do it. When I set it using a light (2 different kinds) to 7 or so degrees BTDC, I could barely drive down the street. I ended up setting it manually to between 5-10 degrees and it drove fine. When I checked this new timing with a light it showed around 30 degrees (if I remember right) BTDC with the hoses disconnected. That obviously wasn't accurate since I don't think a car could even drive with the timing so advanced (especially when you add the advance). A while later I noticed that one of the battery posts was corroded so I cleaned it up and the timing light showed a bit closer (15 degrees or so) to what it actually was. I still can't figure that one out.
My reasoning for why you might be having a similar issue to mine is that when you advanced the timing it ran much better. That suggests that before, your timing was too retarded, regardless of what the timing light was showing you.

[dlb]

it's possible that LD3 has a similar strange timing problem to what you had, mark, but i think it's unlikely. i think 99% of the time, you can and should trust the timing marks to be reasonably accurate. there is always a possibility for something weird to occur but i would not bet on it.

i think advancing the timing a little will usually make the engine feel a little more peppy, regardless of whether it's really the best overall timing for engine. plus i think dieseling on shut-off when it didn't before points to the timing being too far advanced. although, to be sure of this, LD3 should confirm that he adjusted the idle speed to a reasonable level after advancing the timing -- idling too high can cause dieseling too, and advancing timing does increase the idle speed, so that's a possibility.

[Mark]

I think I'm just an evangelist for a new "don't trust a timing light" movement. My application for official religion status is still being processed. I think if the colander-on-the-head guy can get his Church of the Flying Spaghetti monster recognized, I have a good chance. I think my gospel of casting out timing lights is my way of explaining a phenomenon that I don't understand. I admit my experience with them (and only on my wagon) confuses me still.
Seriously though, I agree that my experience with timing lights probably won't be quoted in any Haynes/Chilton manual anytime soon.
Another thought that has nothing to do with timing...is the throttle set up properly? I haven't read the manual on this, but when the gas pedal is fully depressed, is the throttle plate in the carb wide open? It's unlikely, but I assume if it was out of adjustment, it's possible that the throttle plate might not be opening fully.

[LD3]

I have the car idling around 900, which I believe is what the manual suggests. The other concern I have (mostly because I don't fully understand the system) is the vacuum advance. The hose that I was told to unplug, was removed (dlb explained this was because the diaphragm doesn't work) so if the hose is removed already should the timing read 13 when its 5 or will it read 5 when it's 5? I know that's a poorly worded question but I'm hoping someone can figure out what I mean.

Also dlb, this was all happening before the car sat for 5-6 months. The plugs are new, the e-brake is good and would revving easily in neutral be a sign of good fuel? Or even with low fuel will it rev, as there is no load on the engine?

Thanks guys

[dlb]

haha, i get what you're asking. because the diaphragm for the manifold vac advance is broken and disconnected, the timing at idle will not be advanced. so the timing you see is the true base timing. you can set this anywhere between 5* and 10* BTDC.

in neutral, it doesn't take much fuel to rev the engine up. it is when the engine is under load, like going uphill or lugging the engine in too high a gear or weighed down, when fuel demand is highest.

[LD3]

Alright well I'll check the fuel filter. Any other suggestions on getting better fuel flow?