It Ain't Running Right!

[Reverend]

So, first of all, i've been gone from the car circles for a long time for certain reasons. Have forgot most what i learned about carbs and timing.

 

Problem: last summer, i broke my distributor. Yes, it went broken. The collar that holds dizzy on place (with 2 10mm screws) was bent and eventually dizzy started to wiggle, so forth destroying all screw threads that were holding it to place. SO. I replaced it with similar kind of oem 240z distributor (no-points, custom made) and i just CANT make it run nicely.

 

I have 3 SK/OER dual sidedrafts that were tuned last summer. Havent touched them since. I dont remember the basics of timing, but i have timing gun with igniton advance setting.

 

Tell me what are the correct numbers for proper timing on 3 carbs. We tried every combo. It sometimes idled super smooth, then when rpms raised, ran like $^!#.

 

In two weeks we have major car event here, i just need it to be done with before the show.

 

Thanks in advance

[240260280z]

Try 15 degrees initial timing with no vacuum advance. Don't go over 38 at max.

Do you know what the mechanical advance is on your distributor?

[Reverend]

I havent got a slightest idea. By initial timing you mean ..? Sorry for my non-professionality on this matter. I've just had so much stuff on the platter and i've forgot all this.

[240260280z]

For initial it is just the timing at idle (800 to 1000rpm) using the timing light.

Do you need to set up the carbs too?

[Reverend]

Carbs are set up and synced by the tuner last summer when i had the previous dizzy operational. I tried with 18 degrees initial. It idled okay but as soon as i raised rpms, its started to poppoppoppoppopp on the exhaust. 

Edited April 9, 2015 by Reverend

[240260280z]

Exhaust popping is usually too rich or retarded timing.

First verify timing marks: Check piston 1 top dead centre with the mark on the damper pulley.

Also have a look at exhaust and see if it is spitting soot or stinky like rich fuel burn.

[bartsscooterservice]

SO. I replaced it with similar kind of oem 240z distributor (no-points, custom made)

 

Uhm and how does that look ? Petronix ? No points ?

 

Timing with vacuum unhooked, I would try something like 5 BTDC, hook up the vacuum and blip the throttle, should go no further than max 15 to 17 BTDC on the timing mark on the pulley ( use timing light ).

[Reverend]

I have no vacuum advance as im running triples. The dizzy is modified by one old geezer who does these things. Its basic 240z dizzy, no-points with a small box outside. Nothing fancy. And yeah, i can smell fuel. Actually even my neighbour from 100 feet away can smell the fuel... haha. Wich is weird cause the dyno guy said its "okay". Is it normal that my whole rear area goes super BLACK after driving for some time? It looks like im driving a diesel... haha.

Edited April 10, 2015 by Reverend

[madkaw]

Have you checked timing at 3000 rpm? This would tell you if the mechanical advance is working.

[240260280z]

The carbs seem to have an issue.

If you could take a photo of all plugs together, we could see if it is just one carb or all 3.

Check fuel levels in carbs too.

[Reverend]

 

From right to left 1-6. Brand new plugs, all somewhat black, nr1 is the blackest. I tried to set the timing, but my 2 day old timing lamp went mute...

[240260280z]

Your problem seems to be too much fuel.

4 & 5 seem less rich.

Do you or a friend have an air-fuel measuring device?

Quick and dirty first step would be to lower fuel level if you do not have leaner jets.

You could also get hotter plugs (5) rather than (6) heat rating.