Pertronix: Won't rev past 4-4.5k

[Cutlass372]

Hey everyone, I just installed the Pertronix ignitor and flamethrower coil on my 72 240z. Everything was running ok before I replaced the ignitor and now it wont rev past 4k. I haven't checked the timing yet, but I dont think that would be far off as it was running ok earlier. When it hits 4 to 4.5k its like it hits a rev limiter and backfires. I disconnected the BR and put a wire in between the 2 that were coming off it (with 2 male connectors). Everything else is still connected like the condensor and stuff. Where do I look? Any help would be greatly appreciated.

Thanks, Elliot.

[beandip]

Check the timing. Don't take anything for granted. What was the timing set at before, 10* BTDC ? What does the instructions indicate with a Pertronix. I know the ZX setup but not the specifics on a Pertronix. With my ZX I am running half again the advance. However try 10* and see how she runs. If this is all you have changed then that helps greatly figuring out what is going on.

Gary

[WarrenZ]

I had a similar problem some time ago, prior to fitting my Pertronix ignition, maybe you read the thread, there may be some ideas there or a process to follow.

http://www.classiczcars.com/forums/showthread.php?t=28875&highlight=rev

It can only be 2 issues, spark or fuel. If all was OK before then one would think fuel is not the problem.

Check you have not disturbed or prevented the vacuum advance plate from moving. Check the condition of your distributor cap and rotor, mine was 30+years old and badly worn. Your pumping a lot higher voltage through those old plug leads and cap and rotor, they could be breaking down.

Warren

[WW2Winger]

Does it not rev past 4500, or does the tach just say it's not reving past 4500? Upon first installation, mine ran fine but the tach stopped at around 4500. I changed the coil to a different ohm and it works great now. ZSONDABRAIN wrote a good write up on this issue.

[Cutlass372]

No, it does not rev past 4500. As it reaches 4500 it surges like its hitting a rev limiter and then backfires.

[ChrisZ]

I say your ignition is to much advanced, try to retard it one or two marks .

Chris

[Cutlass372]

How do i do that? I'm not very used to these cars. I know the cap doesn't spin so do I spin the dizzy?

[Zs-ondabrain]

loosen the 10mm bolt on the neck of the dizzy, turn the dizzy clockwise to retard it. then retighten.

[Cutlass372]

Thanks, I figured it out while waiting. The timing was almost fully retarded, so I advanced it a little at a time and It wanted to be fully advanced. I got it to rev to like 6k in neutral and 5.5-6k under load, but it still doesn't rev freely through its range. Where should I look now? I still have the condensors hooked up, so maybe I should take them off? What do you suggest?

[ChrisZ]

As Dave said.

On the side of the dizzy is a advance plate, if you look at it you will see a A and a R and also some degree marks, do you self a favor and notice where the pointer is before turning the dizzy, try to retard two marks to start with.

Chris

[Cutlass372]

I took out the BR and made another wire with 2 male ends to connect them together. Is this right? Also where does the condensor near the coil go? On the positive or negative and do I really need it? I should take some pictures or something so you can see what I did.. I just cant seem to find the cord for my camera...

[Cutlass372]

^^ Look up 2 fast 2 Z, I think maybe you were typing after I posted.