383 Backfiring
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
383 Backfiring
My car is a work in progress. I bought the car with no carb and va;ve covers and stuff but the distributor was still in. When I 1st started t it would start up but it would backfire so I checked all the wires and the 8 and 6 were in the wrong spots. Then I noticed the whole firing order was off by one space each 1-8-4-3-6-5-7-2 with each one being in the previous numbers spot. So I put them in that firing order with the #1 cylinder starting at about the 6:30 spot on a clock. Now the car wont even start and it will backfire on the cylinders but wont start. Anyone know what could be wrong?
Junior Member
Joined: Jul 2002
Posts: 75
Likes: 0
From: Sahuarita, AZ
Car: 1991 Camaro RS
Engine: L03 305 TBI, nearly stock
Transmission: 700R4, stock
Axle/Gears: 3.23 out of a V6/5 speed car.
I have to ask a silly question; did you check that the wires were going around the cap in a counter-clockwise direction??
I did that snafu once, and beat my brains for hours figureing out what happened!
I did that snafu once, and beat my brains for hours figureing out what happened!
Joined: Mar 2000
Posts: 43,187
Likes: 46
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Whoa, there, Trigger, where on the cap the #1 spark plug wire is, is irrelevant. All that matters is that the proper spark plug wire is on the cap terminal where the rotor is when that cylinder is supposed to fire. You could have #1 back by the firewall and the others in order as long as that's where the rotor was when the #1 cylinder is supposed to fire. What you did is send the spark to cylinders that are no longer at TDC.
If you "want" the #1 spark plug wire to be at about 6:30 on the cap, then you're going to have to make sure the rotor points there when #1 cylinder is at the ignition position. It sounds like the distributor was put in one drive gear tooth off from the "normal" position, but that doesn't make a bit of difference as long as the timing is set properly for that condition.
If you "want" the #1 spark plug wire to be at about 6:30 on the cap, then you're going to have to make sure the rotor points there when #1 cylinder is at the ignition position. It sounds like the distributor was put in one drive gear tooth off from the "normal" position, but that doesn't make a bit of difference as long as the timing is set properly for that condition.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
So should I keep the wires in the 1-8-4-3-6-5-7-2 order but put them back one space like they were?
You really need to get # 1 cylinder at TDC on the compression stroke first, Then where your rotor button points is #1 position and put your wires on in the correct firing order, which is as listed above, 1-8-4-3-6-5-7-2, and I believe it is clockwise rotation. I was told once also that if you are at TDC on the compression stroke, the rotor should point to #1 cylinder, but that isn't necessarily the case. Like someone mentioned above, It can point anywhere as long as you put #1 spark plug wire there and then do the correct firing order. Hope this helps.
Junior Member
Joined: Jul 2002
Posts: 75
Likes: 0
From: Sahuarita, AZ
Car: 1991 Camaro RS
Engine: L03 305 TBI, nearly stock
Transmission: 700R4, stock
Axle/Gears: 3.23 out of a V6/5 speed car.
oops! My post was unclear! I said to check if the wires were counter-clockwise, but forgot to add that they shpuld be clockwise!
The simplest way from here is find #1 TDC (with both valves closed - you might want to remove the driver side valve cover to verify, or just have a buddy hold a finger over the open spark plug hole - while you crank the motor, untill they feel compression, then stop cranking and line up TDC on the balancer).
Where the rotor sits, start the # 1 spark plug wire there, and go around the firing order - clockwise from there.
The simplest way from here is find #1 TDC (with both valves closed - you might want to remove the driver side valve cover to verify, or just have a buddy hold a finger over the open spark plug hole - while you crank the motor, untill they feel compression, then stop cranking and line up TDC on the balancer).
Where the rotor sits, start the # 1 spark plug wire there, and go around the firing order - clockwise from there.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
All the wires are in the right order and they go clockwise around the distributor. I guess i'm going to put the wires back one spot like they were and see how it runs, and i'm going to keep the 6 and 8 wires in the same place instead f how they were at first. It doesnt help that all the work is in a garage with just hooker headers and y pipe hooked up. i'l try it out this weekend and let you guys knw how it goes.
Trending Topics
Joined: Mar 2000
Posts: 43,187
Likes: 46
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Do you have a timing light? If not, don't bother, because no matter which cap terminals you put the wires on, you still need to rotate the distributor body to set the timing. There is no reason you couldn't leave the wires where you put them, rotate the distributor body to align the rotor to #1 when the #1 cylinder is at TDC, get it started, and then set the timing with the timing light.
Any other efforts are going to be moot until you get the timing set properly, which can only be done with a timing light.
Any other efforts are going to be moot until you get the timing set properly, which can only be done with a timing light.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
I know I need to do the timing,the problem is with the firing order or whatever the car is in now it wont even start to do the timing. I can get a timing light if I can get the car to start but thats my trouble all it does is pop in the cylinders but wont start up and run.
Joined: Mar 2000
Posts: 43,187
Likes: 46
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
There isn't anything going on here that doesn't need to happen when you first assemble and start up an engine.
1) Bring the #1 cylinder to TDC in the firing position (TDC has both a firing and an exhaust/intake position, it has to be the firing position).
2) Observe the orientation of the rotor. Either put the wires onto the cap so that the #1 wire is at the terminal that the rotor is pointing to, or pull up the distributor to move the shaft to a different cam/distributor gear tooth so the rotor points where you want it to for #1 (doing the latter will un-align the oil pump drive shaft - no biggie, but something you need to know is going to happen).
3) Start it up, and set the timing where it belongs.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
I'll hafta do all that, first I think I am ging to put each plug wire back one spot to see if that makes a diffrence because if the car ran once with the way that was it hasta run again, plus the 2 wires were in the wrong spots. I bet if I put them each back one place it'll run then I'll just needa time it.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
I'll let you know how everything goes, I'm heading over to the garage in a bit. Hopefully the car starts in this 20* weather.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
Well I put the plugs back the way they were the 1st time just with the right firing order. The battery was dead so I couldnt start it so hopefully it'll be good for the weekend. I got another question though when i put the car at TDC I lined up the two marks on the cam and crank gear. Then when I went to go turn the balancer it would make my intake valve open with the #1 piston back down, am I on the right stroke?
Joined: Mar 2000
Posts: 43,187
Likes: 46
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Cam & crank timing gear dots aligned is the #6 firing position, typically.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
Well i put the cam at 6 o'clock and the crank gear at 12 o clock and then put my timing gears back in.
Supreme Member
Joined: May 2006
Posts: 1,857
Likes: 0
From: Maui, Hawaii
Car: 1984 Trans Am
Engine: broken 385sbc
Transmission: G-Force rebuilt T-5
Axle/Gears: Currie 9" Ford 4.30:1
ah, a fellow 84 TA with a stroker.. i had problems like that too.. but mine was MAJOR.. my timing light showed 90 degrees advance.. haha.. just bring the motor to TDC, put the distributor rotor pointing to the #1 cylinder.. put your plugs on the way they should go, in order.. then #1 plug on dist. cap with rotor tip, secure down.. start, time, lock down and go get em..
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
I'll hafta wait to use a battery this weekend then I'll let you guys know how. Like I said before though the car ran once but it was backfiring and the 6 and 8 cylinders were out of place it was firing 1-6-4-3-8-5-7-2 so I switched the 6 and 8 and then noticed the order started at 5 o clock on the distributor so I moved them and then it wouldnt even start. So now I moved them back but kept the firing order right. Just need the battery now. When it ran though it was lopey as all heck and loud enough for my dad to hear in the house with the garage shut and everything.
Member
Joined: Feb 2007
Posts: 169
Likes: 0
From: Rio Rancho, New Mexico
Car: 85 Trans Am
Engine: 383 ci
Transmission: Liberty Geared Tko 600
Axle/Gears: Moser 9" 4.11 gear wavetrac locker
did you build the motor? one other thing what are those cam swaps. i think there is a cam swap that changes the firing order but i cant remember what the firing order change to.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
No I didnt build the motor but that cam is a crane cam I think where they switched the 4 and 7 cylinder, and No it doesnt have that cam I'm pretty sure it an edelbrock performer rpm cam. soon to be changed if I ever get the thing running.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
Ok well I went to go start the car and when i turned the key the starter went for a second and then it slowed down like it was dying and then I heard clicking with the starter gear turning but the flywheel not. Anyone know what's wrong with this PITA now? Could it be a weak battery? Could there be water or something in my engine that froze since it's 20* out and it wont let my crank turn? I hardly doubt this because I can turn it by hand. It's very tight and hard to turn and I am a pretty strong guy. Any know whats going on now?
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
Well this battery is about a month old, but trying to start the car alot and freezing cold weather, and installing a new stereo might mean it is dead. I used a jumper pack and still nothing but the pack might be low.
Thread Starter
Senior Member
iTrader: (3)
Joined: Sep 2006
Posts: 629
Likes: 1
From: Worcester
Car: 1984 Firebird T/A
Engine: 406sbc
Transmission: TH400
Axle/Gears: Moser 9"
I swaped in a new battery and the engine fired right up instantly, no backfiring, just a little off, due to wrong timing. The car will be timed to 36* total timing.
Thread
Thread Starter
Forum
Replies
Last Post
LT1Formula
Engine/Drivetrain/Suspension Parts for Sale
7
Oct 8, 2015 08:34 PM






