Author Topic: What can be said about my spark plugs?  (Read 11229 times)

Offline 1979C20

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Re: What can be said about my spark plugs?
« Reply #15 on: April 11, 2011, 03:28:55 am »
Well, I took her for a test "race" and now it has low power. And slow acceleration. It was a loooot faster before I changed the timing. And it backfired through the carb. How to I check for pinging? Can it be heard at idle? Because while I was adjusting my carb i could hear what sounded like beans rattling fast in a can. Maybe my balancer slipped? And my timing is advanced too much? I have no EGR, I removed it because of.really rough starting when it was in the 40's here. It would missfire baaaad and I had to try and get the rpms up to 3k with out it stalling and hold it there for like a minute to clear it out and even the idle.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline topp

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Re: What can be said about my spark plugs?
« Reply #16 on: April 11, 2011, 09:49:41 am »
Removing your EGR because of poor cold starting accomplishes nothing.  Your timing needs to be set properly, your carb has a choke to control cold starting and that must be set properly, as well as your mixture.

I am betting your issues all stem from the fact that you are running an overly rich mixture as evident in your original post.

Get back to your base timing, Adjust your mixture properly.  Then you can start advancing the timing and readjusting the carb as the idle will change as the timing changes.
'90 Suburban TBI 350

Offline 1979C20

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Re: What can be said about my spark plugs?
« Reply #17 on: April 11, 2011, 11:38:58 am »
Well, I even came on the forum about the truck not wanting to start in the cold abd they said it was probably the egr. I removed it and havent had any issues. And, once again, how do I check for pinging?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline beastie_3

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Re: What can be said about my spark plugs?
« Reply #18 on: April 11, 2011, 11:55:17 am »
you will hear it, usually when accelerating or when the engine is under load.

Offline 1979C20

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Re: What can be said about my spark plugs?
« Reply #19 on: April 11, 2011, 01:19:07 pm »
Well, I have headers and glasspacks that dump right under my seat, so I cant hear anything while accelerating other then "ROOOOOAAAAARRRRRR". So, is it possible to tell from under the hood where it isnt quite as loud. What sound am I looking for? Is there any other way to check for pinging?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Grim 82

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Re: What can be said about my spark plugs?
« Reply #20 on: April 11, 2011, 01:35:23 pm »
Advance it a little more. If it's too far, it will kick back at the starter when you crank it over. If it does that back it off some, or if your tab is accurate try 10, then 12, etc. With your manual trans you can run low rpm in high gear so it's under load and lean into the throttle a bit and you might hear pinging over the exhaust. That would be a giveaway of too much advance.

That sounds like a lot of turns out on the idle mix screws for a q-jet, but I guess the plugs don't lie. Good luck
Give a man a gun, and he might rob a bank. Give a man a bank, and he might rob the world.

Offline 1979C20

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Re: What can be said about my spark plugs?
« Reply #21 on: April 11, 2011, 02:05:52 pm »
And just so I kniw im not just retarded, advancing, you turn the distributor counter clockwise's and retarding youbturn thw distributor clockwise, correct?
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Grim 82

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Re: What can be said about my spark plugs?
« Reply #22 on: April 11, 2011, 02:34:28 pm »
On a sbc turn it counter clockwise to advance, clockwise to retard, when looking at it from the top.
Give a man a gun, and he might rob a bank. Give a man a bank, and he might rob the world.

Offline 1979C20

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Re: What can be said about my spark plugs?
« Reply #23 on: April 11, 2011, 04:22:52 pm »
I did the nm low rpm in high gear thing. I did not.hear anything that sounded like pingin. So ill try advancing my timing. Ill advance it, adjust.thr.idle, then shut off and restart to check for kick back.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline ohio hab

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Re: What can be said about my spark plugs?
« Reply #24 on: April 11, 2011, 07:18:45 pm »
You stated that the engine has r43ts plug's in it. That plug is too cold for that engine. I would definitely put in R45ts. This plug will burn hotter keeping your plugs cleaner. I would gap them at .40 or .45.

Offline 1979C20

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Re: What can be said about my spark plugs?
« Reply #25 on: April 11, 2011, 08:31:27 pm »
No, im planning on buying r43ts's. I have a set of auto lites that checker said are for my truck. Well,.my engine was pinging at idle. I retarded the timing and its not making the beans in a can sound, and its running a lot better. So it was pinging, which is probably why it ran like crap.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Grim 82

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Re: What can be said about my spark plugs?
« Reply #26 on: April 12, 2011, 08:25:44 am »
If you have it set where you like it make sure to read the tab so you have a baseline to go back to.
Give a man a gun, and he might rob a bank. Give a man a bank, and he might rob the world.

Offline 1979C20

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Re: What can be said about my spark plugs?
« Reply #27 on: April 12, 2011, 01:30:36 pm »
Well, I went out to my truck this morning and it wouldnt even sputter. So I checked and had no spark. I checked the power lead at the cap and it was good. A month or so ago my distributor gear ground down to nothing and stopped turning. I got an old distributor from a family friend and threw it in to get it working. I figured it happened again, so I pulled the cap and checked to see if the rotor turned when I cranked the engine. It did, so that wasnt the problem. So, I grabbed my old distributor with the chewed up gear. it was fairly new, as were the internal parts. So I swapped out the ignition control unit and the condensor, put it back together and It started right up. Im going to swap in a new pick up coil, probably when I do the plugs. Im going to play with the timing tonight, I think I can still hear some pinging, but im going to make sure I get as much advance as I can. Also going to recheck the plugs and see how their burning.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF