73 with 280 motor su's

[yetterben]

Okay i adjusted my valves the other day they where out of spec but not that bad. Error on the side of to loose rather than burn one. Now today i am driving around it is is backfiring la little from tail pipe. No biggie i think it is like 90 here and humid as sin. Richened up the mixture a little same thing. Wtf i whip out the timing lite and somehow my timing was at 25 or degrees advanced at idle WTF i adjusted my dizzy as far as it would go and now its at about 13-14 i dont get it how could that happen. it was adjusted to 14 before the valve adjust.

kinda scrat5ching my head here. Is there two spots to adjust are dizzy? it is the 280 dizzy. i always just loosen the screw near radiator and go to town. But now i seem a little down on power but it could be just me. Hits hard after 3 grand but before its just average. could be just me though.

Thoughts?

[yetterben]

No ideas?

[yetterben]

Today i took here on another run. I had noticed the temp gauge was about one needle thickness higher than normal since this all happened. Take a hard left crack it open in 2nd and pop pop. Pulled into the next parking lot whipped out my timing light and i was back to 0 re adjusted to 12 btdc. Power is back needle is back down on temp gauge. Only thing i can think of is sticking advance unit in the dizzy?

[Weasel73240Z]

Today i took here on another run. I had noticed the temp gauge was about one needle thickness higher than normal since this all happened. Take a hard left crack it open in 2nd and pop pop. Pulled into the next parking lot whipped out my timing light and i was back to 0 re adjusted to 12 btdc. Power is back needle is back down on temp gauge. Only thing i can think of is sticking advance unit in the dizzy?

Sticking advance sounds like a good guess. Are you running a stock 280Z dizzy, or a newer E12-80 type? The advance plate on the E12-80's are notorious for breaking.

[yetterben]

1280 its back to normal for now anyway.

[Weasel73240Z]

I bought a new breaker plate for my E12-80 at a Nissan dealer...still available but they ain't cheap (about $85 I think).

[yetterben]

never rebuilt a dizzy. Just need it to hold together till the winter. Since that car has been modified its getting a l28et this winter. I just did not know if that is a good guess as to whats going on.

[beandip]

From your first post it sounds like it is too rich and unburned fuel is causing the backfire. Of source the advance/retard situation can cause it also. Ruining retarded will cause the engine to heat. Changing the advance plate is not a big deal.

there easy. Before you do one though disconnect the rubber hose that attaches to the ''dash pot'' on the dist. with the dist cap off look down inside the dist and suck on the tube and see if the advance plate moves. At the same time if it does move seal the end of the tube with your tongue and see if it holds a vacuum. If there is a vacuum leak the dash pot is faulty. If it holds a vacuum but the plate doesn't move , then the advance plate is toast.

Gary

[yetterben]

it clearly works sometimes though. like right now its fine. its more sticky than anything like it can advance fine just not find home all the time.

[Weasel73240Z]

it clearly works sometimes though. like right now its fine. its more sticky than anything like it can advance fine just not find home all the time.

When the advance plates go bad, the little steel ball bearings tend to fall down into the guts of the dizzy. That may explain why the advance works sometimes and not others. You may have a ball bearing jumping around in there screwing things up.

[yetterben]

yeah yesterday it spit on me again could not tell if it was threw carb or exhasut pipe. when i got out the timing was still fine though. Its always in 2nd or when i turn a corner in 2nd. Its not fuel releated either. Have mechanical and aftermarket electric 3 psi and plenty of fuel. MAybe the sudden accel/cornering is making bearings zip around like you said. Would i be able too said bearings?

Anyone know for sure specs on the zx motor. Everything i can find says 8 at idle seems low. whats good for total advance?

[yetterben]

are the dizzys on these cars slot driven or gear driven? If slot driven than it should not matter how its put back in and you should be able to move plugs wires. Meaning bring motor to tdc and move number 1 plug wire to the spot on cap its gonna fire next and rewire as normal.

Hope that makes sense it has worked on other cars with slot drive not gear. After all the dizzy does not care where teh wires are it makes contact in counter clockwise direction. So if the rotor is at 3 o clcok but the motr is tdc then you would just put number one wire at 3 or 6 or 9 depending where rotor is.