diagnosing running rich

[nvrbdn]

I was heading down the freeway going to the drive in. When we pulled into town the Charger just died. I messed with it for quite some time playing with the carb and finally got it to run if you held the gas pedal to the floor. Then kept throttling till I could adjust the idle to get it to run. Got the Charger home under its own power. One guy following me that afternoon told my buddy that I was really gassing him out. So I decided to rebuild the 650 Holley double pumper. The car fired up and seemed decent, but not perfect. So I decided to change the plugs. When I went to Napa this old dude says I am running too hot of a plug for my set up. (I have a rebuilt 30 over 383 with a cam and headers, petronix flame thrower distributor and coil. The cam is lift 484 duration 284 picture off the box included) He said when you add cam, you run a cooler plug. Now for the life of me I have no clue how I came up with the plugs I was running, but they were NGK. So he gets me the stock plug for the engine which is RJ12YC Champion. after all this, the car just doesn't seem right. Well I ran to the speed shop today and they said that the petronix Dist. probably doesn't like the match with Champion and I should be running an NGK plug. I said that was what was in there before, but I already threw them away. They were fouled anyway. They also said that the float level may be my rich problem. So here is where I am at. I can rebuild an engine, take things apart and put them together blah blah blah..... but that's it. I am not a guy that knows why this and that go together to make things purr. What plug would be best for my set up? Which carb would be right for my set up? I am ready to just go buy a new carb and plugs and get this thing running right. The speed shop thinks 600 Edelbrock for the street is perfect. Holley and Edelbrock people say the 600 is all that motor needs. What do the people that are running these engines say?

[BLK 68 R/T]

So...you were cruising down the freeway with no issues and now all of a sudden it became a carb. issue? I'm confused, but it sounds like something else changed. All cylinders firing and getting good spark?

[nvrbdn]

Right, we were cruising about 65 on the freeway. As long as the foot was in the gas. When we came into town there was a red light. As I got out of the gas the car died immediately. I coasted into a car wash. Now, when I got out and looked under the hood I did notice there was a small leak from the front bowl of the double pumper around the gasket. I tightened the 4 bolts and that issue was ended. Just lucky it didn't become a major issue. I attempted to restart the engine with no luck. After several minutes of trying, I sent Steve on to the drive-in and I called my kid to come aid us. I pulled a plug and stuck my finger in the hole and had the wife touch the key to check compression stroke and matched it to the cap to see that I didn't jump time. All seemed to be fine so while I was waiting for the kid to show up I tried again to start the car by holding the pedal to the floor. It fired up, but died as I let off the gas. So I had her turn the key as I worked the throttle and adjusted the idle up high to keep the engine running. At that point the kid showed up and he followed me home so I could get the car back. It ran like crap going slow, But ran half decently while running down the freeway on the way home. After rebuilding the carb it did pretty good while hitting a few car shows locally, but then I changed the plugs since I knew they were the ones that I had in the car when it had the problem. That's where I am at now,   But, the engine was running rich according to the car following me. They were in a convertible and I guess they were not enjoying the ride.

[c00nhunterjoe]

Hard to say without being there but almost sounds like a needle and seat is stuck.

[nvrbdn]

Thanks for the feed back. And what about the plugs? Is it that you use a cooler plug when you put a cam in? And the pertronix needs a certain plug? Thanks. I am a plug and play guy. And when components don't like each other, I am lost.

[bee1971]

Hard to say without being there but almost sounds like a needle and seat is stuck.

X2

Or a heavy float , or set high

[bee1971]

Thanks for the feed back. And what about the plugs? Is it that you use a cooler plug when you put a cam in? And the pertronix needs a certain plug? Thanks. I am a plug and play guy. And when components don't like each other, I am lost.

Pull the plugs and see what they look like , black = rich / wet = gas washed or fouled and not firing

Compression / cam / fuel will determine a colder or hotter plug

What # NGK where you running prior ?

[nvrbdn]

That's my problem, I don't remember what the plug was. Not thinking about it, I threw them away. I am in agreement with out of adjustment floats etc.......    The plugs I had pulled out were black. I will pull these and look at them. On these plugs I might only have 100 miles at the very most.

[metallicareload99]

What kind of choke do you have, and what was its position during all this ? A stuck needle and seat makes sense, but I would think a carb rebuild would have fixed that. A "sunk" float also makes sense to me, and is easy to check

[c00nhunterjoe]

Odds are you have low compression pistons in your rebuilt 383. The hotter stock plug is fine and would not cause an instant problem after driving anyway

[nvrbdn]

What kind of choke do you have, and what was its position during all this ? A stuck needle and seat makes sense, but I would think a carb rebuild would have fixed that. A "sunk" float also makes sense to me, and is easy to check

Its a manual choke. The choke wasn't connected to a pull off, and I believe it was open. But as you are questioning its position, I can not 100% assure you that it was since I had no control over it. That would surely explain being rich and not wanting to restart etc...... Now, the rebuild didn't happen until after the drive-in incident. I rebuilt the carb in the next couple days. She fired up and sounded much better. Then I decided to swap the plugs. and here I am.

[nvrbdn]

Odds are you have low compression pistons in your rebuilt 383. The hotter stock plug is fine and would not cause an instant problem after driving anyway

  That is my assumption that the pistons are a low compression. I guess I will just go get the NGK plug that is cross referenced to the RJ12YC Champion to make the Pertronix happy, And just watch how they are running. I am going to pull the Champions today and see what they look like.

[c00nhunterjoe]

The brand of plug will not make or break the ignition system and in your case, 1 heat range will not either. Something else sparked your instant poor running problem.

[Dodge Don]

Hard to say without being there but almost sounds like a needle and seat is stuck.

Had same thing happen to me. Went to a car show running great. Start it up to go home and running like shit, felt like missing cylinders....surging...smell of unburnt fuel, could see people behind me waving their arms in their cars as I gassed them out. Managed to get it home. Carb float stuck. Had to fix it, pull and replace all plugs that were now black and do oil change as fuel got into the oil pan.

[nvrbdn]

Had same thing happen to me. Went to a car show running great. Start it up to go home and running like shit, felt like missing cylinders....surging...smell of unburnt fuel, could see people behind me waving their arms in their cars as I gassed them out. Managed to get it home. Carb float stuck. Had to fix it, pull and replace all plugs that were now black and do oil change as fuel got into the oil pan.
[/quote]

Yep, I changed the oil and filter, rebuilt the carb and changed the plugs.  Since I rebuilt the carb I have a hesitation on acceleration. So I don't have 100% confidence in my carb building skills and am thinking I will just replace the carb.

[nvrbdn]

The brand of plug will not make or break the ignition system and in your case, 1 heat range will not either. Something else sparked your instant poor running problem.

  That may be the key to it all. I wont say how instant it may have been. The car had only been on short jaunts for shows and cruises that were within 10 to 15 miles from the house. Then on this trip it was freeway driving, then through a town 25 minutes away to grab others, back on the freeway for about a half hour of straight running. Then into town. It could have been an issue that didn't show because all the other trips were a few miles and low speeds. I am glad that you guys with the knowledge have explained certain things to make it easier to break it down.

[c00nhunterjoe]

A speck of dirt stuck in the needle and seat will show under low/no load moreso then higher rpm and loads.

[krops cars]

We run a lot of pertronix in the fork lift industry. I do not care for them much. The Spark plugs you run are the same as oem. I have put Holley's on. New and used. They are temperamental. I would say Edelbrock. 600 to small for a big block. I would at least get a 700. I tried 2 new holley's on a car. Ran like crap. Yes I know how to rebuild and set them. Installed a used Edelbrock. Ran awesome. Edelbrock on the street is the only way to go. Just my opinion. Racing I would use a Holley.

[nvrbdn]

We run a lot of pertronix in the fork lift industry. I do not care for them much. The Spark plugs you run are the same as oem. I have put Holley's on. New and used. They are temperamental. I would say Edelbrock. 600 to small for a big block. I would at least get a 700. I tried 2 new holley's on a car. Ran like crap. Yes I know how to rebuild and set them. Installed a used Edelbrock. Ran awesome. Edelbrock on the street is the only way to go. Just my opinion. Racing I would use a Holley.

I am hearing more and more that the Edelbrock for the street, Holley for the strip. Thanks for the input.

[c00nhunterjoe]

Never had a problem with a holley being tempermental. Its almost always the installer that has a tempermant issue. An edlebrock or a holley doesnt matter. They are both controlled fuel leaks. Tune one tune the other.

[nvrbdn]

Never had a problem with a holley being tempermental. Its almost always the installer that has a tempermant issue. An edlebrock or a holley doesnt matter. They are both controlled fuel leaks. Tune one tune the other.

  You have good answers. Straight to the point. And you made me laugh on this one. Thanks. The fun thing about conversations like this is that you will find diehards on both sides. I have had shops and people tell me that Pertronix works better with certain brand plugs. Others say that a plug is a plug. Some like Holley, Some like Edelbrock. Some say a big block needs a larger carb. I was told anything under a 750 is a bad choice.  While others say a 600 is fine.
     The best part of it all is that it comes down to either a needle and seat were dirty or a float was malfunctioning. I am not a professional rebuilder and will replace the carb with a new one and leave the rebuilding to the people that excel at it. I really appreciate everyone taking the time to discuss this issue with me.

[firefighter3931]

NGK XR5 plugs are what you should run....readily available at any parts store.

https://www.summitracing.com/int/parts/ngk-3332/overview/


The 284/484 cam is very healthy in a 383. It won't make much vacuum at all which makes tuning the fuel curve difficult. A double pumper style carb is the right choice with that engine combination. It's important to dial in the ignition with an overcammed low compression build. That combo is going to want at least 20* base timing and 36-38* total.


Ron

[c00nhunterjoe]

Never had a problem with a holley being tempermental. Its almost always the installer that has a tempermant issue. An edlebrock or a holley doesnt matter. They are both controlled fuel leaks. Tune one tune the other.

  You have good answers. Straight to the point. And you made me laugh on this one. Thanks. The fun thing about conversations like this is that you will find diehards on both sides. I have had shops and people tell me that Pertronix works better with certain brand plugs. Others say that a plug is a plug. Some like Holley, Some like Edelbrock. Some say a big block needs a larger carb. I was told anything under a 750 is a bad choice.  While others say a 600 is fine.
     The best part of it all is that it comes down to either a needle and seat were dirty or a float was malfunctioning. I am not a professional rebuilder and will replace the carb with a new one and leave the rebuilding to the people that excel at it. I really appreciate everyone taking the time to discuss this issue with me.

Giving the same long drawn out detailed story over and over and over gets old and hard on my thumbs. I dont try to be harsh but sometimes it comes across that way. Dont get me wrong, i like holley more and am a die hard towards that platform. Even an old school 4779 is more easily tuned then an eddy, and when you get into the higher end dominators proforms and quickfuels the adjustability if threefold.

[krops cars]

I did not say that the 2 Holley's I put on were new. The Edlebrock was 1 year old. Ordered new Edlebrock. I do agree with 750.

[bee1971]

Odds are you have low compression pistons in your rebuilt 383. The hotter stock plug is fine and would not cause an instant problem after driving anyway

  That is my assumption that the pistons are a low compression. I guess I will just go get the NGK plug that is cross referenced to the RJ12YC Champion to make the Pertronix happy, And just watch how they are running. I am going to pull the Champions today and see what they look like.

Did you ever pull the Champions to see what they looked like ?

Black / Rich ?

Gas Fouled ?

[c00nhunterjoe]

Odds are you have low compression pistons in your rebuilt 383. The hotter stock plug is fine and would not cause an instant problem after driving anyway

 That is my assumption that the pistons are a low compression. I guess I will just go get the NGK plug that is cross referenced to the RJ12YC Champion to make the Pertronix happy, And just watch how they are running. I am going to pull the Champions today and see what they look like.

Did you ever pull the Champions to see what they looked like ?

Black / Rich ?

Gas Fouled ?

With a flat top piston sitting about 20 under 0 deck, .041 gaskets, racer brown ssh 42 cam (think mopar 509) and 516 heads the stock autolite plugs in mine were always good. I would pull 1 or 2 each spring and put them back in.
http://www.dodgecharger.com/forum/index.php/topic,124876.0.html

[nvrbdn]

Here is what the Champions look like. They are clean on one side and have discoloration on the other. These are the plugs from 4 and 8.

[nvrbdn]

The brand of plug will not make or break the ignition system and in your case, 1 heat range will not either. Something else sparked your instant poor running problem.
[/quote

            Yep, I agree. The NGK plugs were in the car when it was running rich. I think the carburetor has been the issue all along. then when I rebuilt the carb and wanted to change the plugs, I am not sure that I fixed the problem and the car is still running rich which I wanted to blame on the Champion plugs. As I looked at my 650 DP just now while pulling it off, the throat is as black as can be. So is the intake. It is very possible that I have a float out of measurement.

[bee1971]

The plugs look wet and gas washed


Float issue s or needle and seat s

[nvrbdn]

Yep, I am retiring from rebuilding carbs. It is off the car and a brand new one will take its place. and next Thursday this car will be at the drive-in.

[bee1971]

Replace all the plugs before installing the new carb

What did you purchase

[c00nhunterjoe]

Those plugs do not look fuel fouled.

[c00nhunterjoe]

Did you verify if fuel was running out of the boosters ?

[nvrbdn]

Did you verify if fuel was running out of the boosters ?

no, I just seen how black the inside of the carb was and decided I really did not get this carb rebuilt to where it corrected the problem. After it was off I did throttle it and had gas coming out, but not out of the boosters. It seemed that the primary flow was poor. I will take it to a rebuilder I know and let him do it properly.

[c00nhunterjoe]

Carbon or soot buildup is not from fueling in the carb. It is either backfires up through the intake or oil being drawn through. What air cleaner do you run? Stock style with hose from valve cover? Pcv?

[nvrbdn]

Air cleaner is a small chrome disc as seen in the pic. PVC valve is hooked to the vacuum port on the rear base of the carb. Is this too much draw from there?

[c00nhunterjoe]

If those valve covers have baffles in them, you should be fine. If there is no baffles and you can see the rockers, you are probably sucking oil through the pcv

[bee1971]

Those plugs do not look fuel fouled.

I see zero carbon on the first few threads , nothing

Threads look almost wet to me like gas and shiny clean

Electrodes are shiny clean , no carbon

Have him pull the dipstick to see if there is gas in the oil

High = Gas in oil

Low = PCV or Valley Pan Gasket

You mentioned PCV

Also intake valley pan sucking oil possible

[nvrbdn]

Those plugs do not look fuel fouled.

I see zero carbon on the first few threads , nothing

Threads look almost wet to me like gas and shiny clean

Electrodes are shiny clean , no carbon

Have him pull the dipstick to see if there is gas in the oil

High = Gas in oil

Low = PCV or Valley Pan Gasket

You mentioned PCV

Also intake valley pan sucking oil possible

He was relating to the carb throat being black. I was thinking it was black due to too much fuel or something. He was stating that it would be from backfires or oil. I have never heard the engine backfire, and the pcv valve hose was connected to the rear base port on the carburetor. The pcv valve is a pollution device that I am not sure needs to be hooked up and think I am going to just let it vent and not be connected to vacuum. The oil on the dip still looks clean. I will probably just change it anyway. It has around 100 miles on it. The pic will show the dip stick pulled just now. No gas smell. I even had my wife smell my finger. Ha Ha. Just oil smell.

[nvrbdn]

Did you verify if fuel was running out of the boosters ?

The arrows show where the fuel shoots from when throttling.

[BLK 68 R/T]

That's the accelerator pump discharge not the boosters.

[nvrbdn]

That's the accelerator pump discharge not the boosters.

Right, He was asking if fuel was running out of the boosters. It was not as far as I could tell.

[cdr]

Did you verify if fuel was running out of the boosters ?

The arrows show where the fuel shoots from when throttling.

That squirt-er is installed 180 off, the notches that you can see go the other way to keep it centered

[nvrbdn]

Ah, thanks.

[69wannabe]

The 650 should work good on that engine, I built my buddy a 383 with 30 keith black pistons 9.0 to 1 with open chamber heads, mopar dual plane intake and moper distributor set at 18 initial with 18 mechanical with a total timing of 36 degrees and he is running a 625 street demon carb that actually runs the engine really great. The only difference is the choice of the cam, I put the XE274 comp cam in this engine vs the mopar 284/484 which is a good 10 degrees bigger in duration @ 50 which makes it a good bit bigger so driveability may suffer and engine vacuum will suffer also. getting your timing dialed in should help like Ron say's and should be the first thing you do and once the timing is set then work with the carb and get it dialed in. Once you get the timing set up the carb will come around alot better. Depending on the actual compression I have seen some run a XR4 NGK spark plug since the 4 is a little hotter than the 5.

[nvrbdn]

Well, I may have to take this thing to a real mechanic instead of me trying to figure it out. It may be that the cam is just all wrong for me, or something else. I ran compression and am at 110. I put a 600 carb on to check everything out. It fired right up and had no hesitation on throttle. but when I ran timing it was running around 30+ degrees. (being the tab goes to 20 so I estimated the extra space. This is a pertronix flame thrower dist. with a matched flame thrower coil. Mechanical advance, so no vacuum running to it to pull while doing timing. When I tried to retard the timing it gassed me out of the garage. I played with it a bit, but had no luck keeping it running half decent without being out around 30+ degrees advanced. So today I pulled #1 and on the compression stroke at top dead center ( I used my camera and watched the piston to assure it was there) checked the timing mark and it was right at the 0 degree mark (actually a few degrees retarded). Then I checked the distributor and seen where #1 should fire. It was stationed between 1 and 8 on the cap. So in my mind, TDC on compression and cap lined in the vicinity of #1 and timing mark lined up, a simple adjust while running and it is all sweet. But not here. I am lost. and with the attempts to retard the timing, the plugs do look fouled now.

[c00nhunterjoe]

110 psi will put you in the 8:1 range if not lower. It will want 25 initial timing and try 38 total to start and increase from there. Depending on your quench and fuel quality you will most likely end up with 42 total. Thats a low comp motor for sure that will be difficult to perfect but will run ok once sorted out.

[nvrbdn]

Thank you. I appreciate you hanging with me on this one. I am heading back out to put it all back together and will get the Holley rebuilt and await its return. So I am headed back out to fine tune the timing.

[nvrbdn]

Well. Here is how things went today. I put on an Eddy 600 cfm carb while the 650 goes off to rebuild. I gapped the plugs to 40. I put the timing at around 30-32. ( where it is most happy)  The engine fires right up, and at throttle it has no hesitation. It has a bit of a rough idle (as expected) but drives out really nice. When cruising in second and punching the pedal it will plant you in the seat. Lots of power and aggressive. I am assuming that when I get the 650 DP back on there the top performance will improve, but have to say that this car hasn't ran this good in a long time. Thanks for all the input. If I knew what I know now about the cam I bought for 100.00 at a swap meet back in the day, I would have bypassed it. But I do love the sound of that thing.

[c00nhunterjoe]

How did you set the timing at 30-32?

[nvrbdn]

I copied the degree length on the tag since it only goes out to 20 degrees in 5 degree increments. Made a tape that attached to the timing tab with the extra 5, 10 and 15 degree marks on it. It may not be a perfect science, but it sure worked well. 

[bee1971]

Eddy 600  

Well at least you know you had carb issues , and I still think you had misadjusted floats or heavy floats or needle and seats sticking looking at those spark plugs and the issues you described

I hope whoever is rebuilding that Holley at least installs new floats also

Me personally , especially after you said the car hasn't run this well in a long time with the Eddy installed  

New Edelbrock AVS 2  650 for the street  

[nvrbdn]

The guy that will be rebuilding the carb has been in business in the St. Louis area for 25 years, Then retired the business and moved it into his garage. And the plus is that he is a Mopar guy. He will do me right.  On the other hand, Yes, this was a carburetor issue from the start. And I am actually getting good at pulling plugs on a big block with headers. LOL