...can i not get the number 5 spark plug out?!?!?! oh yeah, it's cause the hooker headers i bouhgt don't allow me enough room for a socket and i can't fit a box end on it. Anyway, main question is my car was running fine one day then the next it started backfiring and not idling, I figured it was the distributor (it's done it before w/the same results) but I thought I'd check the plugs too...all of the ones I could get out are jet black. Cleaned those up and now i'm going to pull the dist. and take a look at it...anyone else got ideas?

 

running pretty rich there, eh? when was the last time you replaced your O2 sensor? Check your timing too.

 

Is it carb'd? Have you tuned it? Sounds like you're running too rich and backfiring sounds like a timing issue. As for the spark plug problem, I took a plug socket and cut about an inch off of it and pulled out the rubber thing inside of it. Now I can slip it on any plug and then use a 7/8 wrench to turn the socket.

 

http://www.slponline.com/view_product.asp?P=30102

I was too lazy/cheap to order it, so I had my machinist friend make a custom socket for me. I'll post a pic in a minute.

 

Here's the one my friend made for me. Got those plugs on and off without issue.

 

It is a carbed motor...it had been doing really well for a long time. Then I went to start it one cold night and it was acting up, been doing it ever since. It's a Holley 4150, could I have the Fuel pressure up too high, it's at 6-7psi. Timing is hard to check, I (being an idiot) forgot to put in an arrow set to read it when I built the motor, but we can usually get it in the ballpark. And I've got 2 plug sockets, I guess I could chop one down a little bit.

 

6-7 is perfect. I think timing is the issue. You need to set a timing mark, I think. You might be able to put a screw driver or something in the #1 spark plug hole to check the piston position as you turn the motor by hand, just pull the screw driver out while you're turning so it doesn't wedge in there. When you find TDC mark the timing cover or bend a piece of wire and attach it to the timing cover with one of the cover bolts. In my experience, backfires are usually timing related. Did you ever check the plugs before it started running bad? Maybe over time they just loaded up until they fouled enough to cause misfire.

 

I used a piece of white tape at approx. TDC, not the best but it helped w/the initial timing, I'll try to mark it more accurately. It's always had a problem w/fouling the plugs. I'll clean them all off really well and try again...it's hard to check timing when the car won't stay running.

 

If they've always been fouling then you need to tune your carb. Here's a good place to start: http://www.bob2000.com/carb.htm