Look too lean????

[idrivemopar]

Checking my plugs today, because it seemed my car was struggling a bit at highway speed, just felt lean at higher RPM and such, so I pulled the plugs, and this is the result, which seems too lean to me!!! Anyone agree or have different opinion?

 

[mmissile]

Guessing...I'd say yeah.

 

[lewtot184]

the rim of the plug has some carbon, the porceline looks clean. i think i'd look at maybe a jet stagger and maybe try taking a degree or two out of the timing. i like clean plugs.

 

[idrivemopar]

What exactly do you mean by "jet stagger"? Not familiar with that term. I will be checking the timing as soon as I get new timing tape, that stuff never seems to stay on, so, that was my first thought is that the timing is off a bit, plugs used to have that nice powdery light brown color.

 

[idrivemopar]

Checked the timing, and its looking pretty good, based on the builders recommendations of 17 degrees, its still where it was at when installed last year. So, I guess maybe my thermoquad has started running lean.

 

[Bigal75]

Like someone mentioned take out some timing. As for wot. I can't tell without doing a few wot runs and looking for the burn ring at the base of the plug. Cut the threads off to check.

 

[mopar 3 B]

You said thermoquad. Are the main metering rods moving freeely in the bore and has engine vacuum changed?

 

[idrivemopar]

Yes thermoquad, the metering rods move just fine, and engine vacuum is unchanged.

 

[mopar 3 B]

If it was running OK before with no changes to the fuel or ignition system. How about a fuel changes. Same grade, alcohol content?

 

[1wild&crazyguy]

what i would do if it's a street driven thing... is ask myself if i feel any surging at cruise 50+mph?
Look into the plug inside where the porcelain meet the inner ring for tan grey near it, if there is...thats good, it can be mostly white at the top but have a color ring near the inner base where the porcelain meets. However make sure the plug isn't too hot a plug, for all you know you could go one heat range down and get plugs that look tan and picture perfect in your mind.
The light marks on each end of where the tang bends is good, thats where you wanna be and shows proper or real close to proper timing initial/centrifugal.
The threaded ring it should reflect the chamber appearance , if it's sooty ...it's fat somehwere, idle mix a lot of the time...but anyways i like it as long as thats not the porcelain melting away at/around the electrode, and i'd 'given you see some little color ring down inside' try 1 range colder in one hole and see how it looks after a day of driving.

If it's not surging at cruise, the 'primary curcuit' is NOT too lean.

 

[idrivemopar]

Hey 3b, been using same grade and brand of gas in her since last year, just filled up again, and still feels the same when driving. Someone mentioned fuel pressure/rate could be an issue, but this is just a mild build, so I think stock pump should be able to handle it with no problem.

Hey Wild, well, that is exactly what I have done, was my first thought, so actually I went from Autolite 66's to a champion rn12yc, my builder likes to use autolite plugs, but I have never liked them, so I switched back to champions, I think mopar engines like them better anyway. I will see how they perform. Why I thought I was lean in the first place is when driving at highway speeds, it just feels starved and kind of rough, but no noticeable surging, although my builder said I could have a lean surge problem, but stepping on the gas at those speeds, she still gets up and goes.

 

[Mopar-Charger]

Off topic question, but mine look like that. However there are parts of the porcelan that is darker than other parts? Also, car surges 50+ put a smaller jet it. Way too lean?

 

[1wild&crazyguy]

Hey 3b, been using same grade and brand of gas in her since last year, just filled up again, and still feels the same when driving. Someone mentioned fuel pressure/rate could be an issue, but this is just a mild build, so I think stock pump should be able to handle it with no problem.

Hey Wild, well, that is exactly what I have done, was my first thought, so actually I went from Autolite 66's to a champion rn12yc, my builder likes to use autolite plugs, but I have never liked them, so I switched back to champions, I think mopar engines like them better anyway. I will see how they perform. Why I thought I was lean in the first place is when driving at highway speeds, it just feels starved and kind of rough, but no noticeable surging, although my builder said I could have a lean surge problem, but stepping on the gas at those speeds, she still gets up and goes.

In general i like a plug thats not already black metal, it's a lot easier to read a light metal or gold color base ring. If it feels rough.. maybe you are on the edge, like a jet away from surge? Do you see the slightest of speckling/specs on any of the plugs porcelain insulators?
What compression /advertised/static and dynamic/cranking@int close are you running in this thing?
octane?

 

[idrivemopar]

My compression is 9.4 - 1, and I always run 91 or higher octane. Not sure about your other question on dynamic cranking. I didn't really see a whole lot specs on the porcelain, but there may be a few, which I know is an indicator of lean condition.

 

[1wild&crazyguy]

i just want to find out if your cranking compression is too high, or if you're using anything other than chevron or sunoco 91...which is the same in other words.
I know for fact some of the engines i have built did not like shell, 76 or arco premium...but liked chevron premium for some reason.
If you see specs on the porcelain... you need to do a couple things, one would be start over on he tune immediately and the second, for now, would be to tak 2-3 degrees out of the timing.

I would lean the primary jets till it surges, then go back up 2 jet sizes, then i would find how much timing i could run initial before the starter kicked back, and run 2 degrees less than the kick back#...then i would see how much centrifugal i could run by increasing it till when at a cruise of 50mph if i stomped on it it would start kacking out...then decrease by 2 dgrees till it stopped kacking/pinging....then setup the distributor for those numbers and run it.

 

[idrivemopar]

Thanks 1wild&crazyguy, I will keep that in mind, I want to put some miles on these plugs first and see how they are doing. By the way, I typically use Shell, its about the only brand around here unfortunately. I wish the local guy that had Sinclair 93 was still around, but he went out of business.

 

[SlinktRR]

Those plugs look fine to me. All consistent color. Very clean, lean yes but no signs of detonation issues on the electrode or ground strap. TQ runs lean by design. As long as you are not getting driveability issues (lean surge, overheat or ping) as said above, I would drive it but maybe do some small adjustments. Just make sure you have a reliable source of good gas.. I have bought bad gas on road trips and had to change metering and timing just to make it to the next station.

Have you tried richer (thinner) metering rods? Since you said you felt it at high rpm try fattening up the power step in the rod from your current setting. Swap them in and then check the plugs again to see if that gets you going towards tan porcelain.

 

[mopar 3 B]

Those plugs look fine to me. All consistent color. Very clean, lean yes but no signs of detonation issues on the electrode or ground strap. TQ runs lean by design. As long as you are not getting driveability issues (lean surge, overheat or ping) as said above, I would drive it but maybe do some small adjustments. Just make sure you have a reliable source of good gas.. I have bought bad gas on road trips and had to change metering and timing just to make it to the next station.

Have you tried richer (thinner) metering rods? Since you said you felt it at high rpm try fattening up the power step in the rod from your current setting. Swap them in and then check the plugs again to see if that gets you going towards tan porcelain.

TQ rods are adjustable. Why not just pull them up in the hole more?

 

[cwhubb]

I apologize for horning in on your thread, how many plugs do you have to pull to get a good snapshot of how the car's running?

 

[mopar 3 B]

As many as there are. If it has 8 pull 8.