280zx turbo timing going crazy

[mylilpwny]

I think i may have posted this twice? Sorry if I did =\

 

Soooooo still trying to figure out why my timing mark is constantly jumping back and forth. Just put in a new crank angle sensor and had no change. I have been searching all over, reading anything and everything just to get no where.. I can't seem to find anyone that has seen this or similar to. Anyone have any advice or had this problem... love to get some help..

 

Tried
-cap and rotor
-plug wires
-plugs
-Ignition coil

-harmonic balancer

-new crank angle

-different timing gun

-no play in dizzy or shaft

[NewZed]

There are no facts in your post except 280ZXT, crank angle sensor, and timing mark jumps around.  

 

Could be as simple as your inductive timing light pickup is too close to another plug wire.  But without some details, nobody can offer anything useful.

[mylilpwny]

which facts would you like? I don't really know how to explain it... I am trying to time my 1983 280zx turbo. The timing mark jumps constantly back and forth from retarted to advanced

Edited August 23, 2015 by mylilpwny

[mylilpwny]

I have also tried a total of 3 ecus and had no change, the inductive timing light pickup is def not too close to another plug wire as well

[NewZed]

which facts would you like? I don't really know how to explain it... I am trying to time my 1983 280zx turbo. The timing mark jumps constantly back and forth from retarted to advanced

1983 is new.  That's a start.  3 ECU swaps is new.  That helps.  How about some timing numbers?  10 to 20, 15 to 16, 5 to 25.  Those would be significant.  Have you looked through the manual?  EFEC-67 describes what the ECU uses to adjust timing.

 

Just trying to help.  There are many reasons timing can move around.  Maybe somebody will feel energetic and make a list.

[mylilpwny]

I have been threw every page of the manual and found nothing I could use for this. Sadly the timing mark does not even hit any numbers it's so far off. If I had to guess to try and better explain I'd say it bounces from 0 to 20 to 0 to 20 to 0 to 20 to 0 to 20 non stop.

 

As we speak I just checked the hermonic ballancer and that has no play. I put it to TDC and the rotor was pointing to #1 so I did not spin the cam gear or anything random like that =\

[NewZed]

I have been threw every page of the manual and found nothing I could use for this. Sadly the timing mark does not even hit any numbers it's so far off. If I had to guess to try and better explain I'd say it bounces from 0 to 20 to 0 to 20 to 0 to 20 to 0 to 20 non stop.

 

I put it to TDC and the rotor was pointing to #1 so I did not spin the cam gear or anything random like that =\

Seems unlikely.  You didn't confirm that you saw page EFEC-67.  Why would you look through the suspension chapters?  Seems more like you're just not sure what you're looking at.  You said you can't see anything but then implied that you can see 0 and 20.  And "spinning the cam gear" doesn't have anything to do with anything really.  Certainly not erratic ignition timing.

 

Sorry, just trying to find your level.  You're obviously new to engines so you're going to have to put some work in.  

 

Give some background on you, and how long you've had the car.  If this is a new problem, if the engine has ever run right, did you do somehtng and this problem cropped up, stuff like that.  You're just a guy who has a problem he can't describe well at this point.  Good luck.

[mylilpwny]

Seems unlikely.  You didn't confirm that you saw page EFEC-67.  Why would you look through the suspension chapters?  Seems more like you're just not sure what you're looking at.  You said you can't see anything but then implied that you can see 0 and 20.  And "spinning the cam gear" doesn't have anything to do with anything really.  Certainly not erratic ignition timing.

 

Sorry, just trying to find your level.  You're obviously new to engines so you're going to have to put some work in.  

 

Give some background on you, and how long you've had the car.  If this is a new problem, if the engine has ever run right, did you do somehtng and this problem cropped up, stuff like that.  You're just a guy who has a problem he can't describe well at this point.  Good luck.

first of all I built this car from ground up for the last 4 years of my life and daily drove it the last 3 months till this happened. I have gone threw everything in the book because everything is brand new from wheel bearings to headliner to carpet to suspension to engine being fully rebuilt and boosted... I can't see when I am trying to time it cause the mark jumps to far but right now in the middle of the day sense you asked for numbers and I looked I gave a guess of where it was jumping from. Also i have spun the cam gear before and had the same problem but this time around it was the first thing I checked and had no issues.

[NewZed]

A dial-back timing light might help you see the advanced number.  I'm just trying to figure out your words.  If you can't see the marks, then how do you know it's jumping?  That's where I get lost.

 

Another clue, overall, might be - why are you looking at it?  Does the engine not run right?  That might offer some guidance.  

 

And the thing about spinning the cam gear still makes no sense.  You might bend some valves, but the CAS is in the distributor, driven by crankshaft rotation, through a gear that spins the oil pump shaft and the distributor shaft.  It's not driven by the cam shaft.  You can have perfect ignition timing control as the cam gear spins randomly.  Sorry, but that's the way the stock system works.  Maybe your crankshaft drive gear is loose.  Maybe the distributor/oil pump drive shaft has play in it.