OK, I finally installed my L28 and everything is hooked up. Turned it over and its popping and backfiring and wont start, which tells me theres a timing issue. Its a 75 280z with triple webers, stock dizzy, MSD 6al, and Blaster2 coil.

 

Here is what ive checked so far:

Its getting fuel

It gets spark

Firing order is 153624

 

Set motor at TDC (compression stroke)

Pulled dizzy cap and its backwards. But it wont let me turn it 180 degrees because it only lines up one way.  Am I missing something? Ive heard of guys switching the firing order on the cap. Now I know Rebello put on a new cap and rotor and modified the dizzy to wire up the MSD. How would it be backwards? I really hope this is something dumb that i'm doing. Here are pics.

 

 

 

 

 

 

 

 

You can change the wires on the distributor or drop the oil pump and fix it right. You are 180 degrees out. Remember......firing order is counterclockwise. Make sure you are TDC COMPRESSION stroke.

Looks like your moon halves are swapped.  Little for big.  I think that means you could move your plug wires ahead three holes each and be on track, with a mystery for a future owner.  Or you can drop the oil pump and relocate the shaft.  Added a picture of mine from a fine-running engine at TDC on the firing stroke.

 

Diseazd makes a good point about firing stroke.  Cam lobes up on #1.  Can't tell from your picture.

 

Cam timing can also cause problems.  If you take the valve cover off, check the notch and groove.

Edited March 1, 201510 yr by Zed Head

in case the photos aren't clear enough, the issue is the tab on the top end of the rod that spins your dizzy isn't in the center of the shaft - it's offset slightly to one side, so the dizzy can only go on one way. easy to get it mixed up (i've done this) and easy to fix - pull the oil pump and you'll see a notch in one side of the part tube-shaped nose of the pump, and there's a small dot machined into one side of the dizzy timing gear shaft that has to be lined up with the notch in the pump. then you slide it up and in and the spiral gears will mesh and the shaft will twist into place (if you're lucky) or be a tooth off and you'll have to go back a tooth and try again. can be done solo, but much easier w/two people - one up top with a pair of needle nose pliers and one below holding the pump. install it w/the dots lined up and the person up top can grab the tab w/the pliers and push the rod down slowly, feeling for the point where the gears disengage and then jump it a tooth and pull it back up while the person below pushes the pump up to keep things in place. this may sound complicated, but once you're doing it things will make perfect sense.

 

i did this myself a couple of times by stuffing a wad of paper towels up under the shaft at the oil pump hole, threaded in a pair of oil pump bolts and stretched a rubber band across them, which gave me the ability to push down from the top, twist and let the rubber band push the shaft back up until i got the dizzy tab lined up. then i used a pair of needle nose pliers with a rubber band wrapped around them (a pair of needle-nose vice grips would be better if you have 'em) to hold the tab from falling down when i went back underneath to put the pump in.  

 

you may have to unbolt the sway bar from the frame rail mounts to get the oil pump to drop - no need to take the sway bar all the way off, just the two surface mount u-shaped brackets that hold it on w/the bushings. if the car is up on jack stands, the wheels will drop and the sway bar brackets will not line up for re-install, but just put a jack under one front tire at a time and lift it up a little and the sway bar will move right into place.

 

hope this helps!

As much as you've done, I think you should drop the shaft.  Not time to start jimmy rigging.  When I did my 240 I had to drop the passengers side of the front sway bar.  I loosened the drivers side bolts and zip-tied that end, put a small bottle jack on the passengers side and dropped it about a foot.

 

But then again you could swap the wires and hear the thunder. 

Since it's exactly 180 degrees off, the wire swapping should work fine, except that the length of the wires may be tight on some terminals.

 

Curious - Did Rebello install the pump and quill?  Mistakes happen.

Ok I'll switch the plug wires just to make sure that's what it is. So how would the firing order go?

Yeah Rebello shipped the motor with pump and dizzy installed. But no plug wires

Yeah Rebello shipped the motor with pump and dizzy installed. But no plug wires

Make sure that you're actually on the compression/firing stroke before you go too far.  Mistakes happen, but it would be a surprise if Rebello made one.  

 

Your TDC marks will align two times per cycle, once on the firing stroke and once on the exhaust stroke.  The distributor will show 180 off like yours, on the exhaust stroke.

As Diseazd suggested, just make sure you are at TDC on the compression stroke, and from where the rotor is plug the wires in 153624 going counterclockwise.

 

Good luck Matt!

Yes that was it! Thank you guys again. I just moved the plug wires 3 spots with the #1 facing backwards. Fired right up! I will drop the oil pump and put it in right. This doesnt really suprise me that it was installed backwards.