Trouble Adjusting Timing. Set at 33?

[emiliog2276]

Today i attempted to adjust my timing with an inductive light. The car is running good but for some reason it shows timing set at around 33. If i move the CAS to make line move to 15 the car will just not run correctly. It hesitates when accelerating and will studder will at idle. I moved the timing back to 33 but this is definately not right. Any ideas whats going on? Thanks.

[marty1mc]

Check your timing belt and make sure it is on properly. I suspect you are off a cog.

[emiliog2276]

Thanks. I have no idea it could be because the belt itself was on wrong, I always assume the car would completely run bad if the belt as on wrong. Can the belt be replaced itself and nothing else or the whole 400 dollar kit have to be bought?

[robomatic12]

It is probably not off by a tooth but rather your method of timing is wrong. What are you using, the PTU loop or the #1 coil pack plug (middle wire)? Sometimes if you turn the pickup the other way it will show a different reading, you will probably find that one is at 33 and one may be near 15. The one near 15 will be the correct marking.

[marty1mc]

Should be pretty easy to tell. If you are adjusting the CAS way to one side in order to get the motor to run, then check the belt. If your CAS is close to center and your reading is 33deg, then check your method.

[BigTDogg (MA)]

Should be pretty easy to tell. If you are adjusting the CAS way to one side in order to get the motor to run, then check the belt. If your CAS is close to center and your reading is 33deg, then check your method.

Defintely wait untill the car is warmed up, then use the PTU loop. If you're reading 33°BTDC, try flipping the inductive pick up; clamp on from the other direction.

[emiliog2276]

Im using the PTU loop method but there is only one marking showing. I flipped it but the only reading im getting is still 33.

[marty1mc]

Is your CAS set approximately in the center when the engine is running properly?

[robomatic12]

Try using #1 cylinder coil pack middle wire, sometimes the cars can be weird and not give you the correct timing marks on one method or the other. But as the others said, the CAS should roughly be in the middle of the adjustment area.

[emiliog2276]

Yeah its kinda in the middle slightly to the left (im going by the bolt position). If i move it completely to the right its when it lands on 15 will not go any lower.

[es.biggs]

I would pull the CAS off and check the pin on the inside - they wear out on some of the 1990 cars. It's not hard to remove, just unplug it and instead of loosening the 3 bolts around it, take the bolts out. The CAS will slide right off.

Check out this post below - my car had a similar problem where I had to adjust it all the way to one side for it to get into time, then it still wouldn't stay right. I took the CAS off and the pin (aka input shaft) on the inside was really worn. It should be a sharp, half-circle shape on the end, flat. Mine was rounded off from years of use. There is a TSB about it, has to do with the way the left head was machined just a hair off in the early production date 1990 cars.

1990-300zx-na-hesitation-t475118-80.html#p5547780

Not guaranteeing that you have this problem, but it could be it - check the production date on the door jamb. Also could be a timing belt issue, hopefully not! And yeah, if you do have to do the timing belt, you should spend the extra money on the whole kit. It's a little over $500 I believe. $500 now or a $1800 rebuild later on, make the right choice man!

[marty1mc]

^Agreed. If it is running well in the middle of the CAS adjustment, then I would look at other things before the belt. Like Ethan said, check the CAS, make sure it is ok. The middle of the adjustment is where the CAS should normally be for 15 deg adjustment.

Also, just to be sure,which cylinder are you using as #1 (driver's side or passenger side)?

Do you have an aftermarket or underdrive pulley setup? Some have timing marks that are not accurate. You can check if the mark is accurate with a plastic straw. Pull #1 plug, place the plastic straw (get a long one) in the spark plug tube into the cylinder. Let it rest on top of the piston so it can move up and down. Rotate the motor and watch the straw. When the Crank damper pulley mark hits 0, you should see the straw peak on it's upward movement. As you move past 0, it should begin to decline. If it does this, then the markings on your crank damper are accurate.

[emiliog2276]

Im going with the passenger side. I'll pull the CAS and check, thanks for the link to that bulletin the picture is really helpful. It seems like the engine might of been swapped, for a 1993 one. I think this because the car is running the newer 1993 and up injectors and connection on harness isnt spliced in, there isn't an AIV connection/soleniod in engine bay which was removed by 1993, and when i removed the plenum and the valve covers there is a stamp under the covers with a manufactured date of August 1993.
The car isn't running bad at all, (just when i moved the timing , but i changed it back to the original spot), idle stable with no fluctuations, acceleration is ok, mpg stays around 13-14 mpg.