Is my timing messed up?

[KenC]

So I started by car up today and it started up just fine and drove fine as well. I drove it about 3 miles to the post office and when I came back out to drive home, the car wouldn't start. I just kept turning and turning; it wouldn't fire up. Then after about 3-4 seconds of turning, it backfired. I let it sit for about 3-4 minutes and then tried again. It just kept turning and then backfired again. The tow truck driver said it might be the timing...

Anybody have any ideas? It seems weird because it's been running just fine and starting fine as well until this afternoon.

[grlaneriejr]

Ken, I think the timing would "go out" over a period of time. Not really sure though.
Did you smell gas or anything? Could it be the cold start valve?

[rs4pro3]

I'd check the timing, that's what my 84 318i did when I purchased it non running, I fixed the timing and it started right up. check the vacume controls for it and the electronic box mounted on the blower cover.

[KenC]

Ken, I think the timing would "go out" over a period of time. Not really sure though.
Did you smell gas or anything? Could it be the cold start valve?

Yeah, it seemed to me like the timing wouldn't just go bad that quickly. I checked the CSV about 6 months ago, and it was working perfectly then... perhaps I should check it again. Would the CSV even need to be used if the engine was warm? It had only been off for about 10 minutes or so.

Also, what would explain the backfire?

[KenC]

check the vacume controls for it and the electronic box mounted on the blower cover.

How do I do this?

[rs4pro3]

The manuals list how to, I'd check the timing first, get it lined to TDC and the rotor should be pointing at an angle right towards the #4 runner on the intake(if I remember correctly).

[KenC]

It seems strange to me that the timing would just get off all of a sudden like that.... is that what usually happens?

[Ryan Stewart]

Arent you belt driven? Could the cam timing be off?

[KenC]

Arent you belt driven? Could the cam timing be off?

It's chain driven.

Are there some electrical things I should check out first before having a mechanic time it?

[DaN]

Go through the usual steps, check for spark, check fuel pressure, check compression.
If you dont have one, follow that route to figure out why.
Most likely not the igntion timing, unless your distributor hold down is loose or something.

[grlaneriejr]

Hey Ken, check your ignition coil.

Mine just went out today. Towed the car home, and the coil resistance was only .19 on the primary and 1900 on the secondary.

My problem sounded just like yours.

[EtaSport]

If it backfired.. then you had fuel running though the engine that accumulated because of a lack of spark. When it finally gets a spark you have all that fuel that explodes and it backfires. My dad blew up a muffler like that.. it was the coil that went bad when it happened to him. Sounds like it could be ignition related.

[KenC]

How do I check the coil? Just with a multimeter?

[grlaneriejr]

Yeah. Use a multimeter, and it needs to have a resistance of .82 on the primary (small outside wire posts) and 8250 on the secondary (small outside post and coil wire post).

If you are lower or greater than these #'s, you have a bad coil.

Hope this helps.

[KenC]

OK, I just bought a multimeter and checked out my coil. I measured the Primary and it was 0.8 ohms. Then I measured the secondary with the multimeter on the 20k ohms setting at I was getting a reading of 7.53 (I'm not sure if should move the decimal place to compensate for the 20k setting on the multimeter though... it's been a while since I've used one). Does it sound like I need to pick a new one up?
Thanks,
Ken