The car was studdering when i drove and seemed hesitant upon acceleration. I pulled a plug out and it was definitely fouled. Replaced the plugs and worked great! Then I changed the wires to some 8mm and now it runs good at low rpm but high rpms it starts to shudder and wont go above 4k. I must have switched the wires somehow but I did them one at a time.

Its a 396 from a 73 camino (i think) and a HEI dist from a 77 vette.

does anyone know or could help me finding the firing order for the motor and which plugs on the dist are in what order?


thanks so much.

Remove the #1 plug (front drivers) then click the engine over till you begin to feel pressure pushing on your finger, then slowly turn in the same direction so that the timing mark on the crank lines up with the "0" on the timing indicator. You then are at top dead center. Pull your cap and where ever it is pointing is the #1 wire position. The distributor turns clock wise so the next wire would be the 8 and so on... 1-8-4-3-6-5-7-2. You should have it all set up then, that is if there was a wire in the wrong order. If you go to start it and you have some back fire throught the carb, then you were 180 degrees out and you can just move all the wires 4 places to the left or right.

If you switched wires around, it should run lumpy at idle. A high speed miss is usually caused by a lack of good voltage at the plug. Check your wires and see if they are all pushed all the way down onto the cap, leaving no gap to jump from the cap to the wire. Check your plug gaps. If they are too wide, then the voltage requirements go up. Try .055 inch for the HEI. Make sure you have the full 12 volts to the HEI, rather than the power from the white resistance wire that the points ignition used. For a test, put a jumper wire direct from a 12 volt source,such as the battery or junction block to the "bat" terminal on the HEI and do a test drive. OK, now I am out of ideas. One test that I have used to confirm that the miss is actually ignition is to put a timing light on the #7 plug and bring the light into the car and drive through your misfire event with the light flashing. This will become erratic if it is an ignition misfire.

Along with what Jwagner has said. Check to make sure they are clicked into place on the plugs.

It might be possible the plug wire boots on the dist cap are not pushed on all the way because some almost have to be smooshed down to make contact inside the cap. I always use dielectric grease on the boots so they slide on nice and wont stick over time to the terminals on the plugs and cap.

If the wires are the cheap kind, it's possible if you had to twist them a lot to put the boots on, you might have damaged the new wires, ask me how I know this.

Rob

The stock setting for HEI is .045" .050 will do fine but as Jwagner pointed out that a larger gap will require more voltage be available from the ignition system. If it is an OEM setup then you should have .045" and thats even what the MSD tech support suggests unless you are running one of their boxes. I found this info on their website:

http://www.msdignition.com/forum/showthread.php?t=3621

The gap is at .35 so i guess ill change them to .45

I'll be working on it tonight and let you know how it goes. Thank you so much for your help.

Also how you do click an engine over? When im trying to get to top dead center what do you mean by click the engine over? I'm just learning so have a little patience. thanks again.

I recently had a problem with the engine not wanting to get above 2500 or so, it turned out to be a crappy coil. Just replaced the module & coil with napa echlin brand and it runs great now.

use your key with the positive wire on the HEI disocnnected. Bump the engine over by bumping the key to the start position

not sure what distributer you are running,but...be sure that you have the right plug wires for your kind of distributer/ignition system. the winding and ohm resistance can be different by application.HEI,points,ect...