rough running....backfiring 350

• Apr 24, 2026

• #46

Ken B

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if the vacuum line to the distributor wasnt in place when/if the timing was set wouldnt it be incorrect?
I am trying to grasp the sequencing of what happened.

 

• Apr 24, 2026

• #47

Sad Sack

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Too lazy to read the past comments but did you put new spark plugs in or just wires?

 

• Apr 24, 2026

• #48

Ken B

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plugs and wires were replaced.

 

• Apr 24, 2026

• #49

Sad Sack

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Ken B said:

plugs and wires were replaced.

Click to expand...

How did the plugs look?
Soot saturated?
Oil saturated?
Clean?
Tan?
Just plain nasty?

 

• Apr 24, 2026

• #50

Ken B

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Same plug just different angles...just pulled it .

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• Apr 24, 2026

• #51

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Ken B said:

if the vacuum line to the distributor wasnt in place when/if the timing was set wouldnt it be incorrect?
I am trying to grasp the sequencing of what happened.

Click to expand...

You are supposed to time them with the hose removed and plugged.

 

• Apr 24, 2026

• #52

Ken B

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Thank you.

 

• Apr 24, 2026

• #53

Ken B

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Anyone have the experience to look at that plug and tell me what you think is going on ?

 

• Apr 25, 2026

• #54

Ken B

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so i think I have the "plumbing" corrected. Now I need to check timing.
guess a Harbor Freight light is in my future

 

• Apr 25, 2026

• #55

Ken B

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So I had a thought, the circled area has a new plate on it, the smog stuff was removed and this plate was installed. Could this, if not sealing correctly be an issue?

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• Apr 25, 2026

• #56

bucket

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That's an egr block-off plate. As long as there is actually a gasket under it, it's "probably" fine. It'd be really hard to botch that install.

 

• Apr 25, 2026

• #57

Ken B

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can i test the gasket with carb cleaner and see if it is leaking?

 

• Apr 25, 2026

• #58

bucket

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Ken B said:

can i test the gasket with carb cleaner and see if it is leaking?

Click to expand...

Yep

 

• Apr 26, 2026

• #59

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Have you checked your distributor cap and rotor?

 

• Apr 26, 2026

• #60

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^^^^^ what he said^^^^ or like I posted earlier, try another ICM.