backfire/dead plug
Thread Starter
Senior Member
Joined: Jun 2004
Posts: 720
Likes: 0
From: Saint Clair Shores, Michigan
Car: 1985 IROC
Engine: 350 TPI (block was swapped)
Transmission: 700r4 w/corvette servo
Axle/Gears: no idea
backfire/dead plug
Alright, if I goto nail my car, and exhaust gas builds up, it will back fire. Im like 99.99% sure that one of the plugs arent firing so its sending gas/air into the exhaust. Im broke right now but I really want to find the dead plug and replace at least just that (when I get paid im getting msd 8.5 wires and a nice set of acdelco plugs)
Do you guys know of anyway to find out the one specific dead plug?
Do you guys know of anyway to find out the one specific dead plug?
Thread Starter
Senior Member
Joined: Jun 2004
Posts: 720
Likes: 0
From: Saint Clair Shores, Michigan
Car: 1985 IROC
Engine: 350 TPI (block was swapped)
Transmission: 700r4 w/corvette servo
Axle/Gears: no idea
also, how bad of an idea is it to drive if its backfiring?
Driving while backfiring? I wouldn't unless you just need to limp it home.
Finding dead plug- easy. It'll be the one that looks "different" than the other 7 when you take it out. Usually sooty black and/or wet with gasoline if it's just a basic ignition misfire.
I'd replace the wire that goes to that plug at the same time. Bad plug, bad wire.... they act exactly the same.
Finding dead plug- easy. It'll be the one that looks "different" than the other 7 when you take it out. Usually sooty black and/or wet with gasoline if it's just a basic ignition misfire.
I'd replace the wire that goes to that plug at the same time. Bad plug, bad wire.... they act exactly the same.
Thread Starter
Senior Member
Joined: Jun 2004
Posts: 720
Likes: 0
From: Saint Clair Shores, Michigan
Car: 1985 IROC
Engine: 350 TPI (block was swapped)
Transmission: 700r4 w/corvette servo
Axle/Gears: no idea
:| unfortuantly thats my only means of transportation, what kind of damage am I looking at if I keep on driving it?
Thread Starter
Senior Member
Joined: Jun 2004
Posts: 720
Likes: 0
From: Saint Clair Shores, Michigan
Car: 1985 IROC
Engine: 350 TPI (block was swapped)
Transmission: 700r4 w/corvette servo
Axle/Gears: no idea
I just got done testing each one of the wires, the one wire on the far rear passenger side sparks inconsistantly. it will go like:
spark spark spark ... spark spark spark spark ... spark spark ...
does that mean I should replace my cap and roter?
spark spark spark ... spark spark spark spark ... spark spark ...
does that mean I should replace my cap and roter?
Rotor going bad wouldn't affect only one cylinder. Cap could just be bad on one terminal, but it's more likely the plug or wire going to it that's bad. Usually. In most cases. Not always. Your mileage may vary.
If you can possibly replace everything (spend money which you don't have) you wouldn't need to play the guessing game.
It's just that MOST single-cylinder ignition misses can be traced to the plug or wire on that cylinder. Usually. In most cases..........
If you can possibly replace everything (spend money which you don't have) you wouldn't need to play the guessing game.
It's just that MOST single-cylinder ignition misses can be traced to the plug or wire on that cylinder. Usually. In most cases..........
Senior Member
Joined: Dec 2004
Posts: 627
Likes: 2
From: Warren, MI
Car: 1989 Firebird Formula
Engine: 305 T.B.I. (Vin tag "E" = LO3)
Transmission: THM-700-R4
Axle/Gears: 10 bolt posi 3.23
if u dont feel like pullin the plugs to find out which cylinder is missing u can jus start to pull 1 wire off a plug at a time. if the engine starts to die, put wire back on plug, this means it is not that plug and repeat process to other 7 plugs. do this if yur lazy
Trending Topics
Thread Starter
Senior Member
Joined: Jun 2004
Posts: 720
Likes: 0
From: Saint Clair Shores, Michigan
Car: 1985 IROC
Engine: 350 TPI (block was swapped)
Transmission: 700r4 w/corvette servo
Axle/Gears: no idea
I'm going to wait untill I get paid to buy new wires, plugs, and possibly a nice new distributor. I also need to buy gaskets for my headers because one of them is leaking. Other than that all I have to worry about is the vacum system and lack there of. But yeah, friday is going to be fun.
Thread
Thread Starter
Forum
Replies
Last Post
wigmobile
Electronics
5
Feb 26, 2025 02:56 PM
89 formula TPI
Tech / General Engine
10
Sep 7, 2015 11:06 AM





