Timing?

suzuki
samurai

#1

i last year i changed my timing belt and the manual was wrong, but that’s not the ?, when i changed the timing belt the camshaft was 180 out,and it ran great,last week i changed the water pump and that was when i noticed the distributor was 180 out,the ??? is why it runs the same when it is right and 180 out,


#2

On a four cylinder engine, if the camshaft and distributor are both 180 off, the engine will run fine, with no ill effects. This condition basically swaps the exhaust and power strokes on the cylinders. The engine still does the same job, just in a slightly different sequence. It’s difficult to explain, but it will work the same and not harm the engine. It could have potentially made diagnostics more challenging if something else had gone wrong.


#3

no, only 1 is off,the crank and cam are on TDC the dist. is 180 off, when i turn the cam 180 to get the dist on #1 it still runs the same,great,


#4

If the engine runs fine with only changing the distributor 180 degrees, then it looks like:
[list]Your camshaft-timing belt timing is correct, and[/list]
[list]Your ignition system is the kind that fires both on the intake and on the exhaust strokes.[/list]


#5

Wasted spark ignition would be a great answer except that he already stated that the cam was 180 out as well as the distributor.

Or am I getting confused?

By the way, Joe, if the criteria describibed in your reply were the case this would be the best “stump the chump” question ever.


#6

MB:
I too was a bit confused. In the opening post he definitely said the cam and distributor were off. Then I read his reply (a bit too quickly) thinking he said only rotating the distributor. His reply is still a bit unclear to me.


#7

I’m still unsure myself.

But I gotta tell ya, if someone were to say the camshaft and crank were properly timed and the engine was running good with the distribuutor 180 out, I’d be stumped. I never would guess a wasted-spark ignition system. What a great stumper that would be.


#8

“… camshaft was 180 out …”

Had you rotated the crankshaft one full turn such that cylinder #1 was again at TDC you’d have seen the camshaft was now correctly phased. The distibutor follows the camshaft.

That’s why the engine ran correctly. Everything is assembled correctly. There’s no such thing as “180 out” for a single camshaft engine. Now, if you had more than one camshaft, and they weren’t both timed the same, well that’s a different story.


#9

Hi again, sorry for the confusion, i looked in the factory manual and the haynes manual has the info wrong, thanks for the help, it stumped this chump, the haynes has the cam timing mark at 12 o-clock with the mark on the cover, the factory manual has it at 6 o-clock, thanks again.


#10

Again, there is no such thing as “180 out” for the camshaft timing in a single camshaft engine. The camshaft rotates exactly half as fast as the crankshaft. Because of this the timing mark for the camshaft can be at either 12 o’clock or 6o’clock, it’s the same thing. Once set at 12 o’clock, if you rotate the crankshaft exactly one full turn you’ll see that the timing mark on the camshaft is now at 6 o’clock.

Both manuals are correct.


#11

your question amounts to, how come I can time my engine on the no 1 or the no 3 cylinder and it still runs fine.


#12

So if the distributor was in the right place, with the cam off that much, the spark would be occurring when the engine was near the top of the exhaust stroke instead of compression. But with both of them wrong, they’re in sync again, even though you’ve essentially substituted the compression and exhaust stroke for each other.

I was going to say that the computer should be confused because it wouldn’t know when to fire the fuel injectors, but since it must use the cam position sensor to determine this, and the cam is wrong, it still must be firing the injectors when needed. On most engines you can pull the cam sensor connector and the engine will still run, because it will be firing all of the injectors blind instead of in sequence. But this would still work on yours too. Apparently the computer doesn’t care too much if what it sees from the crank position sensor and cam sensor don’t agree with each other.

I wonder, have you seen any decrease in mileage, and is the check engine light on?


#13

I looked up the history of the Samuri. I ran from 1985 to 1995 and its fuel delivery evolved from carburated to TBI, all ignition systems were distributor based.

The problem is really simpler than it initially appears. As long as the camshaft and distributor are coordinated such that the plug fires when both valves are closed, the only thing that matters relative to the crank is that the piston is at TDC. There does not exist a “180 out” with respect to the crank and the cam.