timing chain

[HeWhoKillz]

Ok, I was just wanting to know how a timing chain goes out? I know with timing belts, they break, dry rot, simply get old and worn out. Timing chains? Are they the same way? See I have a 95 sentra which wouldn't start at school. It cranked but not start. After a while, it did start and i drove it home. Once it was home, it wouldn't start again. It will crank but not start. I thought it was a fuel issue. Someone else said timing chain. If it was the timing chain...would it still crank? How can it? If the chain is broken, how does the camshafts get turned?

[inafogg]

its very rare that a timing chain breaks.the cam/crank gears can wear down
& cause the chain to jump.i'd do a basic inspection checking for fuel/spark
a compression test would be helpful.as far as engine cranking with a broken
belt/chain yes it will, but your only moving the bottom end.camshaft/valve
will not move

[curtis73]

If the timing chain breaks, it won't ever start again until you fix it.

First of all, a timing chain slipping a tooth would only happen long after excessive wear has cause other major symptoms. Even then, if it skips a tooth, it wouldn't cause an intermittent problem. it would run poorly until it skipped the next tooth at which point it probably won't run at all.

Not the timing chain

[shorod]

Not that it matters, but does your Sentra really have a chain rather than a belt?

As pointed out, your symptoms are not consistent with a timing chain/belt issue. They could however be due to a failing fuel pump, restricted fuel line (when was the last time the fuel filter was changed?), or possibly a bad Crankshaft Position Sensor (CKP) or Camshaft Position Sensor (CMP). I'm not sure if Nissan requires a valid CMP signal to allow the engine to start, but most likely it atleast requires a good CKP signal. Start with the easy stuff like squirting some throttle body cleaner in to the throttle body when it won't start and see if that will get it to sputter like it wants to start or maybe even get it to start. If so, the issue would appear to be a fuel issue. Of course if you have a fuel pressure gauge you could just use that. If that has no change, then check for spark using a spark tester.

-Rod

[inafogg]

Rod, they did switch to a chain in the later years,just before the sentra was dropped for the altima.just not sure what year the altima came out.i thought it was 95-96

[inafogg]

Originally Posted by curtis73

If the timing chain breaks, it won't ever start again until you fix it.

First of all, a timing chain slipping a tooth would only happen long after excessive wear has cause other major symptoms. Even then, if it skips a tooth, it wouldn't cause an intermittent problem. it would run poorly until it skipped the next tooth at which point it probably won't run at all.

Not the timing chain

who are you addressing this to??
and who said it was a bad timing chain??
the guy asked if the engine would crank w/broken chain

[Blt2Lst]

Maybe an ignition issue, when was your last complete tune-up?

[HeWhoKillz]

My old 93 sentra with the same engine was a chain so assumed this one was to. The spark plugs and wires were changed about a month ago along with oil in about november or december. I was thinking the fuel pump myself since everything seemed to move. I know its a silly idea but could I like put a zip locker baggie over the opened oil cap (to avoid escaping oil)and start it and see if the cams are turning? To test for the fuel pump can I like pull one of the fuel lines from the firewall and see if fuel comes out when it tries to start? Or what other ways can i test the fuel pump? The car has 3/4 tank. I couldn't tell you the last time the fuel filter was changed. Might check that as well.

[shorod]

Originally Posted by HeWhoKillz

To test for the fuel pump can I like pull one of the fuel lines from the firewall and see if fuel comes out when it tries to start? Or what other ways can i test the fuel pump?

If the pump is working you'll get a lot of fuel all over the engine bay that way. I'd suggest one of the two suggestions I made in post #4 above.

-Rod

[HeWhoKillz]

And if its not working then I won't get any gas out of the hose then. Do they sell spark testers at autozone and stuff? I don't own much of this fancy equipment.

[inafogg]

you can get a spark tester for $5, spraying carb cleaner in the trottle body
is an easy way to see if your getting fuel.if it tries to start then you no

[vgames33]

All GA16DE (and the SR20 as far as I know) engines have chains. If your chain broke, as stated, you would have no start and likely a very fast cranking with little to no compression.

The GA16 should have an optical cam sensor in the distributor housing and I have heard of the distributor bearings failing causing some weird issues.

Spark testers are widely available at any tool store. Fuel pressure kits are available as loaners from any parts store. As stated, some carb cleaner or starting fluid can rule out a fuel issue pretty quickly. Just be careful, as I have had some engines backfire and ignite residue in the intake track

There is a no start/hard start TSB for all Nissan models through 96 stating that you may have to pull out the pump fuse or floor the throttle to get the engine to start. It then says to check base idle and ignition timing.

[jdmccright]

Timing chains can wear and become loose enough to throw off the cam versus crank timing, but it would have to be severe wear to prevent starting...jumping a tooth ot two.

I'd look more at a weak ignition coil, a faulty engine coolant temp sensor, or possibly a stuck IAC or EGR valve if it idles poorly when running.

[HeWhoKillz]

Ok so we change the fuel filter and there is gas coming out of the hose when you start the car. Still only spins the engine. It doesn't really sound like its firing. Could it maybe be the distributor? I thought maybe the spark plugs and then I thought how many spark plugs would have to die (or spark plug wires) to make the car not start at all? Not even try???

[jdmccright]

An engine might run on two firing cylinders, but no start means it's not spark plugs...it's upstream electrically. Either the ignition coil, igniter, or the distributor.

Test the coil and igniter (if equipped), check all engine grounds, and in the distributor check for excessive play, broken cap contacts, and melted components.