I just installed a new Distributer Cap, Rotor, Ignition Coil Plug Wires and Plugs. I now hear a buzzing soung coming from the distributer. What Could This Be?

 

Coil not properly grounded.

 

It now misfires at around 30 mph when I am only at part throttle. It won't misfire at any other time. And isn't the ground wire on the ignition coil the black wire that goes to one of the screws holding the coil down.

Also will the wrong spark plug cause a misfire. The Spark Plugs I removed were Champion RV19YC and I Replaced them with Bosch 7585. I looked Up the Part Number on the RV19YC and the bosch 7585 were listed as a replacement spark plug. Although the length of the bosch is a little shorter reach length. The Reach length is the same for both though

 

The center contact in the back (closest to the cap) is the ground wire. Fits under the coil. Make sure you have a good path to ground from there.

4 years ago, I was tight on time and had a shop put a-arm bushings in the '57 for me. I had an HEI distributor at the time. They removed the cap to raise the engine (probably didn't need to be done, but that's what they did), and didn't get the ground wire hooked back up properly - I had individual wires, not a connector pack, and they just stuffed it up there between the terminals. It made that buzzing noise, and broke up at higher RPMs.

They also left the alternator bracket loose, which eventually shook the alternator to the point of wearing out the bearings and breaking a couple of alternator fan blades off - which happened going down the track, of course, cutting the fan belt, which flew up and left a welt in the hood that is still there. All because I didn't have time to puts some a-arm bushings in myself.

Double check your coil ground.

 

Alright, I took the Distributer Cap Cover off and Checked the Ignition Coil Ground Wire. I took the bolt all the way out and put it back in. Now the Buzzing Sound is not as bad, but it is still there. but the car still misfires at around 30 mph at part throttle. Can I have the wrong plug wires. I had some crappy type of 8mm wires on the car and replaced them with 7 mm wires.

Also there are no SES codes That have anything to do with misfire. I only have a code 54 about the fuel pump voltage. I have had this code for weeks and had no problem.

 

Check plug wires 5 and 7. You may have them on backwards.

 

No they are not backwards. I have the Diagram for the distributer and cylinder location. The only thing I found is that some of the spark plug wires had at some point rubbed against the exhaust manifold and cracked the insulation. Could This be the Problem?

 

I'd recheck your plug wires again. Backfiring and lack of power after a cap, rotor, wire swap sounds like you have some wires mixed up. 5 and 7 are right beside each other on the cap and in the head so they are easy to get mixed up. 18436572. Rotation is clockwise. Drivers side head is 1357 Passenger head is 2468

Your new plug wires have rubbed through already? Change them again. Do this little test. Once it gets dark out, start the engine and look under the hood. Are there little blue sparks anywhere? Use a spray bottle and mist down the plug wires. Also make sure the plug boot is pushed all the way onto the plug until you hear or feel a click.

Another test to see if a plug is firing is to install an inductive timing light over each coil wire. If there's something wrong with the plug or wire, the plug won't fire and the timing light won't flash.

 

2 of the plug wires were touching the exhuast manifold and the heat caused them to crack. I had some spare plug wires and replaced the 2 wires that had cracked open. It also could be that the parts I bought were the premuim parts from Napa were carp I work at a shop ( but we are closed on weekends) And we get bad parts from napa and carquest at least once a day. I will wait till it gets dark out and see if the plug wires are arching. The car does run a little better with the 2 spare plug wires on it but I will have to replace them as they were what was on the car originaly. I also checked and all the spark plug wires are where they are soposed to be and the pllug boots are pushed on all the way. I have had issue after issue with this car because the original owner swaped out the 5.0 tpi and put in a 1974 350 and used the tpi plenuim and thottle body off the 305. and the stock 305 prom is pluged into a jet performance chip for the 87 Iroc with the 5.7 liter to keep the car from stalling. the a/c a.i.r pump and egr have been removed too. and i am not getting any signal from my knock sensor when the scan tool was hooked up. I will hook the scan tool up to it on monday and write down all the data from the sensors.

 

Okay, I'll try one more time. . .

There is a flat, bent terminal that sticks in the cap and goes under the coil. That goes to ground. If it isn't there, the wire under the screw isn't going to help.