found a problem need help

[jason-1995fbody]

my camaro has an early 70s 350 in it it had a problem with breaking up at about 4500 rpm so i changed the cap and rotor same thing changed module and went to 8 psi fuel pressure seemed to help got to 5000 no problem now last night tryed to shift at 5500 and it is doing the same thing


my question is well what the he!@ also should i go to a high performance module
or maybe a performance coil (it did the same thing with two different used coils)


also the rotor was new in the box the cap slightly used with brass ends


going to go nuts i was planning to go to the track saturday

[Genopsyde]

need more details on your ignition. it definitely sounds like in ignition problem. is it coil-in-cap HEI? what it your timing set at? spark plug gap?

could also be experiencing valve float.

[jason-1995fbody]

it is an in cap coil hei the timing i dont know dosent have a marker i advanced it till it cranked hard hot then backed it off a little plugs are ac r45 gaped at .035
on a side note i think im gunna get an upgrade kit from summit part number SUM-850030

[Genopsyde]

a hotter coil may be what you need. I had spark issues at first when I made the swap to carb and coil in cap HEI, turned out my battery cables were too small. changed over the bigges gauge cable i could find at summit and it solved the problem. But in my situation it was fouling the plugs constantly. Take a look at a couple spark plugs, if they are black wet and or sooty, then you probably have a weak spark issue. If they are pretty clean and the white part that the electrode comes out of has a light brown coating on it then your spark is good, and so is your carb jetting.

what size cam are you running? and are you using stock heads and valve springs? Since youre problem is happening at high rpm it makes me think you're having valve float.

[Genopsyde]

hopefully Morley will pop in some time today and add some input for you. He has a hell of a lot more experience with this than I do.

[Morley]

The ignition system sounds fine. Don't go aftermarket, especially with the module, they are junk. The plugs sound like about the right heat range (correct for a 77 Camaro), try opening the gap to .045".
To set yur timing, hook a vacuum gauge to manifold vacuum and adjust the timing to get 20" of vacuum. You should be able to easily get 20-22" with a stock cam. Next try backing your fuel pressure down to 6-7 psi, since you dropped it to 8 and things improved I think you could be over fueling.
Next, what brand of carb is it? If it is a Q-jet it could need a rebuild, smaller jets or more likely smaller metering rods. If it is Holley, how is the power valve? One backfire will kill them without the power valve saver installed.
Oh, and used caps are a no, no for me. They have a wear pattern in them from the rotor that was used in them and when you disturb the rotor to cap relation, things can go haywire.

[Genopsyde]

werd!

[jason-1995fbody]

actually i raised fuel pressure to 8 the carb is a reman q jet the cam is not stock but i dont know how big it is as for the caps i know but free is cheep


but any how the car died on me last night no spark so now i have to find the problem:runaround ::runa round:

[Morley]

Originally Posted by jason-1995fbody

actually i raised fuel pressure to 8 the carb is a reman q jet the cam is not stock but i dont know how big it is as for the caps i know but free is cheep


but any how the car died on me last night no spark so now i have to find the problem:runaround ::runa round:

Don't forget to check the pick up coil down in the distributor... Also when you changed the module...did you use the thermal paste under it? If not you probably fried the module...or if it was aftermarket you just found out why I say Only Ac Delco.