J0hn_J0hn08

iTrader: (2)

So i finally managed to swap in my camaros 355 into my firebird.

Problem now is that when i am hard on the gas i hear a really loud pinging noise that increases the more gas i give it.

The engine is completely rebuilt so i suspect the issue is either the timing or the knock sensor.

My main question is how can i time my car properly?

Im running a carb with a summit HEI distributor below.
http://www.summitracing.com/parts/SUM-850001R/


I think the knock sensor could be another possibility..since the knock sensor clip pretty much desintegratred when the swap was being done but i dont know if that has an effect on the sensors performance.

In my camaro the motor never had this pinging noise, but when i swapped it into the firebird i also swapped in a HEI distributor for the first time.

camaronewbie

You no longer have an ECM, so even if you have a knock sensor installed, it's not doing anything. In other words, anything computer related is no longer doing anything, even if you still have the wires connected (since you don't have factory distributor anymore).

You need to either 1) run higher octane fuel, or 2 back your timing off.

To do basic timing on a carbed car, you need to set your timing as high as you can without the pinging, and adjust the carb idle down to accomodate.

Set timing at 10*, then drive (take timing light with you, and tighten dist bolt so you can turn dist but it won't move on it's own). Punch it - probably won't hear any pinging. Then pull over, set timing to 14*, try again. Let's say you get to 17* timing, and you just barely hear pinging at WOT - then move it back 1-2* to like 15* and lock it down.

What you are trying to do, is get the total advanced timing at 3000 rpms as close to 34* total timing as possible. But most distributors don't come with the right springs/weights installed to get that high of total timing.

Mine is set at about 15* base timing. At 3000 rpms, I get up to about 28* total. I can't get to 34 without having the pinging (detonation), because I don't have the right springs/weights installed in the dist so that it advances that far that quickly - I need heaveier weights or lighter springs to get there quicker. Remember, we are dealing with centrifugal forces of the distributor turning to mechanically advance the timing.

I manage to see all this higher numbered timing by using a timing tape - just has marks all around it and literally you tape it to your balancer - order one - measure diameter of your balancer as they are specific. About $10.

Duh - I just reread your post. Are you still using the stock TBI unit? Or are you using a carb now? You cannot put a vacuum-advanced distributor in a computer controlled car.

If you are using the TBI unit, then you HAVE to use stock computer controlled dist.

If you are using a carb, you HAVE to use a vacuum advanced dist - and in this case none of the computer components are doing anything.

Without the computer controlled distributor, you are getting NO timing advance at all, so you can't use that distrbutor if you are using the cars computer.