My distributor had been stripped, so I took it to the auto repair shop and had to have the guy self tap a screw to hold it. When I got home, I noticed that the distributor cap was missing a screw on one of the sides. So I put a hex self tapping screw on it so it would hold the distributor cap onto the distributor. When I did that my car started dying often. It would backfire and gargle at 4k-5k RPMs. I changed the spark plugs and had my friend to re-time them, plus cleaned the injectors using 100 octane gas, used sea foam, plus some Lucas. However the same problem with the backfiring at high RPMs and the car dying still persisted. It began to start and idle just fine when I pushed the distributor cap towards the passenger seat. If I let it go, then it would die. I decided to go ahead and change the spark plugs, spark plug wires, and the distributor. Now… my car will not start at all! Please give me your advice as to what I need to do to get my car in good performing condition.
You probably did not install the distributor correctly. The position of the rotor must be noted and matched to the engine block before distributor removal, otherwise the timing will not be correct. To make things right, the #1 cylinder will need to be placed at top dead center (TDC) on the compression stroke.
Do this by removing the #1 spark plug and putting your finger over the spark plug hole. Have an assistant turn the engine over by hand until you feel compression. Then align the marks on the crankshaft pulley with the zero degree mark on the timing scale mounted to the front of the engine. The engine is now at TDC. Now, turn the distributor shaft until the rotor points at the #1 plug tower on the cap. Reinstall the distributor. If you are not comfortable with this, you may want to leave this to a professional.