Car won't start after replacing the timing belt

[Eric in France]

Hi. I have a 1984 320i and I just changed the timing belt. I put back the covers and the vibration damper, but not the accessory belts (no alternator, water pump, or power steering). Then I tried to start it and in wouldn't start. I know I got the synchronization between the crankshaft and the camshaft right, but I wonder whether the distributor is out of sync. I have a Haynes manual that says (step 13) "Before fitting the belt, remove the distributor cap and check that the notch in the rim of the distributor body is in alignment with the one on the governor. The camshaft and crankshaft marks must not have moved." Well, I hadn't noticed that step before I tried starting the engine, but as far as I know it should have been all right. After that I did open the distributor but I could not see any notch in any rim, nor on the "governor", whatever that is. I supposed that the distributor is turned by the third sprocket around which the timing belt goes (besides the crankshaft sprocket and the camshaft sprocket). So on the supposition that maybe it got moved by a notch or two when I had the timing belt off, I have been trying out various positions. That is, I take off the timing belt, push that third sprocket one way or the other by one tooth, put the timing belt back on (not easy), put back the covers and the vibration damper, and try starting. So far I have tried four notches in one direction and three in the other direction from where it was, but no luck. Am I doing the right thing?

[superj]

When you have the first piston on top dead center, is the distributor rotor pointing the number one wire on the cap?

[Eric in France]

I don't know. How can I tell which wire is which? I am reluctant to take the distributor cap off again because it was so hard to put back on! (One of the two springy things you have to push and turn is very hard to access.) Is it true that the third sprocket has to be in just the right position in order for the distributor to function correctly? I did check yesterday that I have sparking.

[323i E30]

Spark is good, but if it comes at the wrong moment the engine won't run.
I don't know what's keeping your engine from running. I just came in to post the below picture for which wire is which. I hope it helps. Good luck.

BMW-Inline-6-Firing-Order.jpg

[Eric in France]

Thanks. But the picture on the left doesn't look like mine, and in the picture on the right, how do I distinguish between wire 1 and wire 6? I see the protrusion between 1 and 5, but there would be an identical protrusion between 6 and 2 on the back side of the distributor in the photo.

I'd still like confirmation from someone that the third sprocket that the timing belt goes around drives the distributor and has to be in exactly the right position. An old thread I saw (https://www.bimmerforums.com/forum/s...elt-mainenance) seems to indicate that the exact position of the rotor is not important, so long as it delivers the spark to the right spark plug. The exact timing (according to that thread) is determined by the top dead centre sensor.

[superj]

We don't have distributors on our m20s so we can't help with personal experience

[superj]

on other distributor vehicles I have owned, if you pulled the distributor and positioned it back improperly, you could get away with just moving the wires to where #1 wire and #1 at TDC lined up and that got you close enough to start and fine tune it.

put the engine on top dead center of the compression stroke and take the cover off the distributor and line a post up. that post will be number 1 spark plug wire form then on. after that, you just put your other wires in firing order from 1 onwards. I don't have personal experience on the m20s with distributors but I have tons of carb and distributor experience. if your ecu is not controlling fire, like on the fuel injected m20s, then you can set it the way I said.

[superj]

[img]http://imagecdn2.panjo.com/images/ff...b807af4442.JPG[/img]

did that little plug come undone from the side? that's the same style cap clamp that a chevy distributor uses. a flat tip screw driver pops it off easily

[Eric in France]

Replying to your post of 11:48 (French time), the problem still is that I don't know for sure which wire goes to spark plug number 1. I tried using an ohmmeter -- I put one ohmmeter lead inside the #1 spark plug lead and touched the other end to the various metal tabs inside the distributor cap, but none of them made the ohmmeter move! I tried the same on other spark plug leads, but never got any conduction. Now I have pulled off one of the leads from the distributor cap and I did the same exercise but putting the ohmmeter lead directly on the terminal of the lead I had taken off. Still, none of the spark plug leads gave conduction with it! The ohmmeter does give a signal when tested on a piece of metal, so it's not that my ohmmeter doesn't work. Also, as I mentioned earlier, I do get a spark (I checked with spark plug #5 I think). I don't understand why I can't find which wire is which using my ohmmeter. (All six wires go into a sort of hose, so I can't just follow the wire.)

What I'm going to do next (when the weather dries up a bit) is try to get the rotor to connect to what I think is wire #1, while the camshaft is at TDC position. I'll try to use my ohmmeter to check that there's a connexion between the input terminal of the distributor (where the coil connects) and the output terminal that goes to what I think is wire #1. Then I will put leads and the timing belt back on et cetera and try again.

As for your post at 11:59 French time, I don't understand what little plug you're talking about.

[superj]

that's weird. there must be some kind of resistor in the leads.

I guess they are in a pack like the fuel injected e30s. luckily, ours are numbered.... maybe yours have the numbers also?

- - - Updated - - -

sorry, pics don't work here at where I work most of the time, so if you have posted some pics, than I am not able to see

[Eric in France]

It is a fuel-injected E30. I didn't notice any numbers. Printed on the insulation, or what?

No, I haven't posted any pictures.

[superj]

I guess I mis-said what I meant, I forgot yours is fuel injected, its just the ignition system is different. on our spark plug wire loom, the leads are numbered. I assumed yours were different because you have a distributor but yours goes into a loom, also. that is the problem, your set is not numbered. you might have to open the loom and then just try and put it back with zipties to hold it closed once you have the wires figured out

[Eric in France]

I wrote my last post after midnight. This morning I have checked, and sure enough, there are little numbers on the leads! So now I know which is wire #1 (and it's opposite to the one I thought was). But now my next question is, when the camshaft marks line up, do I want the rotor to connect to wire 1 or to wire 6? In other words, piston 1 is at top dead centre at two times during the cycle, and we want the spark at the right one of those two. So it's not good enough to make the rotor point to wire #1 when the crankshaft mark indicates that piston 1 is at TDC -- we have to be sure that the CAMSHAFT is at the right point. There's a mark on the cam sprocket which lines up with a another mark once every two times that the piston is TDC. So do I want the spark when those marks line up, or 180° off of that? Do I want the rotor to be aligned with wire 1 or with wire 6 when the cam marker lines up?

[superj]

an easy way to find the correct tdc for the cam is to put your thumb over the spark plug hole for number1 and turn the crank with a socket. when you are on the right rotation of the cam, the air in the cylinder will push your thumb off the hole. when it does that, put your number 1 wire lead on the pole of the distributor cap that the rotor is pointing at as it will be the number 1 compression stroke lead

[Eric in France]

Thanks for the suggestion, but I can't do it on my car. There's no way I can contort my hand in order to stick a finger all the way down the indentation in the head to reach the spark plug hole. But you've given me an idea. I put the spark plug back in in cylinder 1, and then (with the timing belt still off) turned the crankshaft a few degrees. It was very easy to turn. So I assume that means a valve in cylinder 1 is open, and I should align with wire 6 instead of wire 1. I guess what I'll do (tomorrow, weather and time permitting) is to line the rotor up with wire 6, put the timing belt back and stuff back on, and try it.

[superj]

ok

[Eric in France]

On second thought, the experiment I did is not good enough. When the piston is near TDC (as it was), then turning the crankshaft just a little bit hardly makes the piston move at all, and even if it does it's just creating a bit of a vacuum as it moves down. It's not compressing air to a high pressure. So what I will do (when I get the time) is to put the timing belt back on and then try rotating the crankshaft through 360° or 720°. There should be a 180° range in which it will be compressing air, so it should be difficult, then 180° where the compressed air will be pushing the crankshaft so it should be very easy or even move by itself, and then 360° or so where valves are open so it should be easy. It's after the compression stroke that I want the distributor rotor to aim at wire #1.

[superj]

you can pull the valve cover and look at the valves. when both intake and exhaust are closed, its close to tdc. intake is the side that is nearest the intake manifold and exhaust is nearest the exhaust manifold

- - - Updated - - -

won't be perfect but will get you in the ball park

[Eric in France]

Thanks for the suggestion, but I managed without that. (It would have been quite a bit more work and I might have had to order a new gasket for the valve cover.)

My idea of trying to figure out which part of the cycle it was in by seeing how hard it is to turn the crankshaft wasn't very successful. It was pretty easy to turn all the time. I thought maybe there was a point where it was harder, but I wasn't sure. It could be that my piston rings are leaky so the air pressure leaks away pretty quick.

Anyway, I guessed that when the camshaft marks line up then cylinder 1 is ready for a spark, and I lined up the distributor rotor like to point to wire 1 at that point. It's a bit tricky to get the timing belt on in such a way that all three sprockets are in the right relative positions. One thing I found was that to finish getting the belt on I should turn the crankshaft a bit clockwise until the belt is taut on the right side (actually the left side of the car) and slack on the other side (where the tensioner is). That makes it easy to finish slipping the belt over the camshaft sprocket. Then one can let (or push, in my case) the tensioner back to its "tense" position.

So I put the spark plugs back in, and put the damper on, and voilà the car started. So for future reference, if anybody wants to know, when the camshaft marks line up, the distributor should be giving a spark to cylinder 1, the cylinder towards the front of the car.

Now I have to put the accessory belts back on, or maybe buy new ones, and put the radiator back and connect the coolant hoses and fill the cooling system.

I assume the timing is now the same as it was before I started, unless I have (unintentionally) gotten the distributor sprocket one tooth off from where it used to be, on the timing belt. It looks like it's quite difficult to loosen the distributor clamp in order to turn the distributor, and I don't have a timing light.

One tip on putting the distributor cap back on — it's very hard to push down and turn the rear clip (or whatever you call it) unless you have a very long screwdriver, which I didn't have. But once you push it down (against its spring), you have to turn it clockwise. I was trying to turn it counterclockwise until I realized the the little hook was hitting some piece of metal.

[superj]

Glad it started up

[Eric in France]

Thanks for your help.

Now I have another problem! I put everything back together, filled the cooling system, and then ran the engine at a fast idle till it was warm (as per my Haynes manual), and then topped up the coolant. Everything seemed fine. Then I washed the car (since it had been sitting outdoors for a couple weeks getting droppings and so on), and then started to drive it to put it back in the underground parking garage. But there was a sort of clicking sound! I don't know what it is or why it started only then (maybe I revved the motor a bit more than before). It's hard to tell where it's coming from. I hope it's not something with the valves.

[superj]

put a long screwdriver handle on the valve cover over the first set of valves and lean over and put your ear on the end of the handle. it will act like a stethoscope and allow you to listen. move it over each set of valves and listen and see if one is particularly louder than the other.

if it was a valve being hit though, your car would lose power and be back firing or making other weird noises. maybe it will clear up after a bit

[Eric in France]

I did what you said, and heard valves working, but they all sounded the same.

I eventually realized that the sound is coming from the alternator! When I push down on the alternator, the noise stops. It's like something is rattling. I'm still tryin' to figure it out. Taking a lunch break.

[superj]

that's good. an alternator is way better than valves.

[Eric in France]

You're right about that.

Well, I took of the belt, and turned the alternator by hand, and put the belt back on and tightened it. It's a bit of a problem -- you need to loosen a nut on the back side of the adjuster bolt, and the bolt that holds the alternator on, and the bolt that holds the adjuster on, and it's not easy to access them. I had to screw the fan part way off in order to get a socket wrench onto the bolt that holds the adjuster.

Anyway, after putting it all back the way it should be, the problem has disappeared. Took it for a drive around the block and it seems fine.

Back in the saddle again!

Thanks for your help!