440 backfires thru Exhaust and won’t stay running

[kinghs95]

440 71 Plymouth satellite when I crank key in car it crank but not firing. If I jump it on the relay it fires, backfires thru exhaust immediately and dies. I put distributor in 10 degrees before top dead center. I have advanced and retarded the timing and same thing. I had it running before but the more I started it the hard to start. It would puff white smoke out the top of carb and spit. I took carb out and cleaned it. But I wanted to check everything bc a buddy checked the timing and it was 30 btdc but might have been misread. I took valve covers off and everything was moving looked good. What should I check lol? Can’t keep running a sec or two…so I’m unable to check timing .

 

[WileE]

You have to go back to basics. First, mechanical... is the crank/cam set up and timed correctly ?

 

[Cranky]

Was it running good at one time and then started doing what it's doing?

 

[turbine68rt]

Double check the firing order going counter clockwise?

 

[Rishi]

Engine Timing, be it mechanical (via timing chain between crank and cam) or distributor, is a more common cause of backfiring out through exhaust on engine start.

Unless the mechanical crank to cam calibration is screwed up, you can try changing the timing using distributor position.

Back in the day, without a timing light, I would have adjusted the rotation of the distributor, and the engine timing, as it cranked to find the sweet spot to get it started and/or idling when the timing seemed way off.

 

[kinghs95]

As far as timing I checked the tdc line when #1 piston is up and that’s good. I have broke in the cam before this and started back to back before not ran it longer than 20 minutes or so on a stand. Inside the car on the harness it fired about 3 times and it was hard to start but sounded good. Then I went on vacation for a few days came back and nothing. I have checked the firing order multiple times and good. I can post a video on YouTube and link it to show what I’m talking about.

 

[kinghs95]

 

[kinghs95]

First time starting was key and second was jumping relay. It’s an ebay hei gm type distributor setup which I think I’m gonna switch to summit setup.

 

[turbine68rt]

Might want to check terminal condition of main engine harness at the bulkhead.

 

[Don67Satellite]

You sure you checked your TDC on the compression stroke and not the exhaust stroke?

Backfire out the exhaust you sound 180 out.

 

[BeepBeepRR]

Do a compression test to rule out a burnt valve.

 

[Dave6T4]

I agree with Post # 10. Pull your distributer out, and turn your rotor 180 degrees, and drop it back in. I have done this myself.

 

[toolmanmike]

440 71 Plymouth satellite when I crank key in car it crank but not firing. If I jump it on the relay it fires, backfires thru exhaust immediately and dies. I put distributor in 10 degrees before top dead center. I have advanced and retarded the timing and same thing. I had it running before but the more I started it the hard to start. It would puff white smoke out the top of carb and spit. I took carb out and cleaned it. But I wanted to check everything bc a buddy checked the timing and it was 30 btdc but might have been misread. I took valve covers off and everything was moving looked good. What should I check lol? Can’t keep running a sec or two…so I’m unable to check timing .

Any tune up lately? What has changed since it ran good?

 

[AR67GTX]

I’m with Dave, sounds like distributor was installed off. Maybe 180 degrees out. Maybe something less.

 

[toolmanmike]

I’m with Dave, sounds like distributor was installed off. Maybe 180 degrees out. Maybe something less.

I lost count of how many issues around these forums that are caused by something simple. I also lost count how many people leave out important details when asking for help. All we can do is guess.

 

[kinghs95]

Ok I finally got it started. What I did wrong was I set it 12 btdc and put distributor in and I grabbed the rotor and pulled the direction of rotation to “get the play out” but seems like I was advancing it too much so I was probably off 10-20 degrees by doing that. Basically I moved all the plugs one and rotated engine forward to 10 btdc and had the points of dizzy line up and not touch the rotor and it fired up.


But it seems weak and unbalanced now. I’m thinking I’m gonna check compression/ resistance of plug wires and maybe set the edelbrock carb (driver side )plunger adjuster back to the top hole bc I moved it to the middle but maybe not enough fuel idk. I will say before when it ran it idled 1000 or so and wouldn’t idle much lower than 800 or so but this time (which I never adjusted idle) it was 500 or so.

 

[kinghs95]

Here it is running . Also having issues starting car by the key. I haven’t diagnosed that yet.

 

[kinghs95]

Ps all those zip ties are to mock up the parts lol.

 

[Roscoethug]

My RR had same symptoms. Went nuts checking timing, compression etc. Turned out to be old/bad gas from previous year. Fresh gas solved the problem.

 

[kinghs95]

My RR had same symptoms. Went nuts checking timing, compression etc. Turned out to be old/bad gas from previous year. Fresh gas solved the problem.

I will try that