Help with rich smokey idle
 

Background Info: 350, 9:1, performer rpm intake, headers, 2400 stall converter, 700r4, 3.73, Holley 4160 600.

The car runs great. No hesitations, no flat spots. But at idle the thing will burn your eyes and it smokes pretty heavily.

On a cold start, the motor doesnt smoke, but you can still smell it being rich. When the engine warms up it smokes.

The choke has been converted to manual and the fast idle cam is not contacting, so that shouldnt be the problem.

I have worked through the sticky on holley tuning. I have double checked everything that I can think of. The floats are set right, I currently have 63 main jets, the transition slots are set correctly, idle screws have been adjusted to greatest vac (roughly 1.75 turns out), power valve is good and a 8.5 (could probably go higher), idle vac is 15", idle speed is right around 900 in neutral and 850 in gear.

I dont know what else to do to get the smoke to stop. It doesnt smell like oil, it smells like raw gas.

I looked into air bleed tuning, Im going to try sticking a paper clip in the main air bleeds tomorrow to see if that helps any. But it seems that smaller bleeds increase the fuel flow at idle. Is this correct?

What all determines the fuel mixture at idle? What else can I try? It is embarassing to drive the car when everybody behind you at a stop light cant breathe.

Re: Help with rich smokey idle
 

Timing issue? What's timing set at?

Re: Help with rich smokey idle
 

Well I learned my lesson.

I started to reply back that yes the timing is right.

Well, I thought about it a minute and I decided to go check it. I had checked and set the timing about 2 months ago. I figured there was no way it changed, it is bound to be right. Well, I pulled the vac line to the distributor, put the timing light on and I was sitting at 36 initial, 46 total. Needless to say im back down to 26 initial, 36 total right now.

It just goes to show, regardless of what you think, things change, take the time to check. Thanks for making me second guess myself and getting me to check it out. I was starting to go crazy trying to figure out why the carb was causing it. I know ive got it just about dead on.

Re: Help with rich smokey idle
 

:lmao: No problem.

BUT - 26 initial is still kind of high maybe. I'd take a run at WOT, and listen for pinging/spark knock, if you get any spark knock at all, you need to come down more.

Typically, there's no way to get the magic 36* total from an off-the-shelf distributor ... they don't come with the right weights/springs installed for the advance to increase fast enough to reach 36* before 3000 rpms. So you have to settle for a lower total number until such time as you can get the right springs/weights combination correct so that it advances mechanically enough fast enough. Just setting the initial very high (over about 20*) to get that magical total number of 36 99% of the time means detonation which is not good.

So - might need to back that down some more. But do a few WOT runs and see.

I had to set mine at about 14* initial, and I only get to about 27* total - thus I need different weights/springs combo in the dizzy to be able to get a faster mechanical advance (closer to the 36) before 3000 rpms.

Make sense?

Re: Help with rich smokey idle
 

Well I drove it to work this morning. Got to a stop light and could smell gas fumes. Looked in the rear view mirror and seen it smoking again. Going to double check everything again this evening. I dont know if the timing slipped or if something else aint right.

I havent had any detonation problems so far. I know 26 static is alittle high. I think I could use some more slot in my distributor weights. That is supposed to give more mechanical isnt it? Then I can back down on the static. Last week I got on it and it pinged some. I thought it might have been some bad gas. Now I know what really caused it. But so far at 36 I havent had any problems.

Im going to double check everything again, this is driving me crazy.

Re: Help with rich smokey idle
 

Drove to lunch today. Car doesnt run as good as it did. Has some hesitation to it. Almost feels like a miss when I go WOT. Still smokes some, but not as bad as it was. I'll post up this evening after I go back through the timing and carb.

Re: Help with rich smokey idle
 

Are you checking the transition slots when you pull it off the car or did you adjust for them then put it on then adjust idle?

You want your transition slots to remain at spec when the idle is set. If they aren't then you need to adjust your mixture screws.

So say your slots are showing too much that means you need to back out your idle mixture screws then close the slots more. If its the opposite of my senario then reverse my steps.

Re: Help with rich smokey idle
 

hole 25 is where you want your wire if any.

Some use tag wire, kinda like youd find on a loaf of bread (the green twisty thingy).

I used one of my diabetic needles, was .012 gauge perfect length folded over nicely.

paper clip will be way too thick, ag wire probably your best bet. Be creative.

Worked well.
If you use the needle get a couple youll lose them easy. Any rite aid will have them. Pull them out the end and push in/fold over, gasket and put it back together.

http://www.chevelles.com/forums/atta...6&d=1294969186

http://www.bizmology.com/wp/wp-conte...tes-Needle.jpg

Re: Help with rich smokey idle
 

I set the transition slots then adjusted the idle via the screw on the secondaries. I ground down a small screwdriver that I use for that. It works well.

cuisinartvette, I was under the impression you put the wire in the bleeds and hook them on the choke tower? I didnt know you could also do that with hole 25. Am I correct in assuming that restricting this hole will decrease the fuel flow at idle?

Re: Help with rich smokey idle
 

pulled in the driveway and parked, smoke burning your eyes.

Pulled out the timing light. 24 static, 10 mechanical.

Transition slots look right. Pulled out the vac gauge, hooked to manifold vac, idle screws are at at 1.5 turns. Pulling 16", idling at 800 rpms. And now I feel high from being out there around it. My nose burns and my eyes are almost watering.

This is seriously driving me crazy. I dont know what else to do.

Re: Help with rich smokey idle
 

Where are your floats at? iMo if they are just spilling out when you take the screw out they are too high try lowering them some and lean the metering plate screws a touch. Prefer maybe a turn out opinions may vary though.

Re: Help with rich smokey idle
 

front floats are setting where when I pull the plug, I have to press down on the front to get anything to come out. Secondaries are set to where I have to shake the front even harder to get it to come out.

I really wish I had the money right now to put a wideband sensor in it. Atleast that way I could see exactly what it was doing and how rich it actually is.

I have a couple of holley books, but right now they are 125 miles away. I need to read through them and see exactly what feeds fuel at idle.

Re: Help with rich smokey idle
 

Is it still the hot cam in there or a different cam? A tight LSA would make the idle smell...but not as bad as you are describing. Look down in the carb with a strong flashlight as the engine is idling. Do you see fuel being pulled out of the boosters? How much do you have to turn the secondary screw to get it to idle (1/2, 1 full, 3)? What do the plugs look like after it idles a while? Real wet? Check out these things before restricting hole #25. If these things are okay, you may need to restrict the IFR hole (#25).

Re: Help with rich smokey idle
 

It is still the hot cam and only with 1.5 rockers.

I will check with a good light this evening if it is not raining and get back to you on that one. I looked without a light and couldnt see anything, but I'll check again.

Are you talking about the screw under the secondary linkage? I dont really know. It took awhile to get it right when I set it. I dont really know in total how much I had to turn it. I can get a pic later to show how much it is sticking up above the base plate.

I will check that this evening as well. I have a new plug. I'll warm the motor up and swap it in, let it idle, and I'll pull it and take a pic.

Thanks for the help.

Re: Help with rich smokey idle
 

Was raining yesterday, but I got some stuff today. By the way, fuel pressure is 5psi.

After the car had warmed up I shined a light down the carb, everything was dry. No fuel coming from anywhere.

I was going to swap in a new plug and let it idle some with it, but dummy me got in a hurry and broke the new plug. So here is a picture of the #3 plug when I pulled it. The plugs I am running are Champion RS14YC. I chose those just because that is what came up for the motor when it was stock (97 1500).

Sorry for the bad quality of the pics. Atleast you can get a general idea of it. Looks maybe too hot of a plug or too lean???? Not sure about reading plugs after they have been driven under different conditions. Im down to a 63 main jet, I really think that might be too far on the lean side. I just wanted to see if it had anything to do with the smokey idle. No change from a 65 smoke wise.

http://i513.photobucket.com/albums/t...s/DSC01015.jpg

http://i513.photobucket.com/albums/t...s/DSC01014.jpg

Here is a pic of the secondary screw position.

http://i513.photobucket.com/albums/t...s/DSC01007.jpg

Here is a pic of the secondaries.

http://i513.photobucket.com/albums/t...s/DSC01009.jpg

http://i513.photobucket.com/albums/t...s/DSC01008.jpg

I took a video to show how much it was smoking. I will try to load it.

Re: Help with rich smokey idle
 

Okay, disregard the terrible sound. It doesnt show up very good, but you can still see it. It will seriously make your head hurt from the fumes.

http://i513.photobucket.com/albums/t...h_MOV01011.jpg

Re: Help with rich smokey idle
 

Hard to tell about the plugs from the pictures (pretty fuzzy). They don't look very rich. Any oil deposits on the plugs or threads? Pull your dipstick and smell the oil...does it smell like gas?

You could try to restrict the idle fuel passages in the carb (IFR's...hole #25 in the pictures above). Just do a temporary modification (piece of wire) and see if it makes a difference. Main jets shouldn't affect the idle mixture. All your fuel should be coming from the transition slots (under the throttle blades).

I had a similar situation with my car. I swore it was running rich at idle, even though the O2 sensor and plugs said otherwise. Turns out I was starting to lose my ring seal and it was oil I was burning. Because of the bad rings, the oil really smelled like gas. A compression check found the problem right away (200psi on all cylinders except #8...only 90psi). If the IFR's make no difference, I would do a cranking compression test next.

Re: Help with rich smokey idle
 

I will check/try those things.

Thanks for all the help.

Re: Help with rich smokey idle
 

I checked the oil. Doesnt really smell like there is any gas in it. (cross fingers)

Im going to try to restrict the IFR tomorrow. I'll post up how that goes.

Re: Help with rich smokey idle
 

That sounds promising about the oil. In my case, there was no doubt when I smelled the oil. I am sure it would have caught fire if I had a lighter!

Re: Help with rich smokey idle
 

from a suggestion on another forum (s10v8.com) I pulled a couple plugs, cleaned them up with a wire brush and put them back in just at idle for a minute.

I just done this with #1 and #3. Cleaned them up with wire brush. FYI, they came out a white/brown color. I let it run for alittle over a minute only at idle.

Here is what they looked like when I pulled them.

http://i513.photobucket.com/albums/t...s/DSC01019.jpg

Im going to go try the wire trick. My biggest worry though is "what will happen if I go to lean?" I know lean at anywhere else in the rev range is not good. It cant be good at idle either. The plugs point to lean, the fumes say rich. ARG!!!

Re: Help with rich smokey idle
 

Lean on the idle transition slots may cause you to run a little hot and there could be a small hole in the power when you get into the throttle. Use the wires as a guide. If they work, your next step is to do a permanent fix to those passeages.

Re: Help with rich smokey idle
 

well I took a trash bag tie, burnt the plastic off, and cut short pieces. I put 1 wire in each IFR. There may be a slight difference, kind of hard to tell. Still has some smoke to it. Im going to drive it alittle like this and see how it goes. Thanks for the help.

Re: Help with rich smokey idle
 

I hope the wires are long enough to extend out under the gasket (so the wires don't move around). Drive it a little and see what happens.

Re: Help with rich smokey idle
 

yeah I made sure the gasket would hold the wire in place. Like you said, Im just going to drive it and see what happens. If it does the same, Im just going to keep driving it like it is. If it gets worse, well that will be a good sign of guides or rings needing work.

thanks for the help

Re: Help with rich smokey idle
 

Well I have been driving the car to work for the past couple of days. It still smokes. I am calling it oil burning. I guess synthetic oil produces a fuel like smell when burnt.

At cruise the car is just barely showing signs of a lean surge. Now Im debating on either pulling the wire in the IFR or bumping the jets from 63 back to 65.

Re: Help with rich smokey idle
 

MOST synthetic oil such as mobil one, synpower, syntec etc. are made from crude oil that is simply more refined than there "conventional" motor oil counterparts.

I know from experience that synthetic oil smells nearly identical to conv. when burned.

Re: Help with rich smokey idle
 

How's your compression?

Re: Help with rich smokey idle
 

Some have group IV mixed in though. Besides, Im going to keep telling myself that anyways. There is nothing else that I can find to explain what I am experiencing other then burning oil. And it just doesnt smell the same as what I have experienced in the past.

Dont know. I havent bothered with checking. Truth is even if I found a low cylinder (none are dead, car still runs strong and smooth) then I wouldnt do anything to fix it at this point. I dont have the time or the fiances. So until a problem is obvious, Im going to just continue to drive it as is.

Thanks for the help though. It is always appreciated.

Re: Help with rich smokey idle
 

Ditch the synthetic next oil change and run a straight 30W conventional. Maybe the heavier oil will reduce the amount being burned. It's worth a try.

Re: Help with rich smokey idle
 

I had planned on changing the oil this weekend as it was. I'll give that a try. Like you said, it is worth a shot.

Re: Help with rich smokey idle
 

Any change?

Re: Help with rich smokey idle
 

had some personal issues come up this week. Havent changed it. I doubt it changes. Like you said, the oil should smell the same burning regardless of what type it is.

Going to try it anyways. I'll post up when I get a chance to change it.

Re: Help with rich smokey idle
 

Alright. I messed with the car some this weekend.

I changed the oil and messed around with the carb.

When you fire it up, no smoke. When it starts getting to operating temp it starts smoking and the hotter it gets the more it smokes. Now with the new oil, Castrol 10w-30, the smoke doesnt smell as much like raw fuel.

I messed around with the carb. I even done things that I know is wrong to just see if it made any difference. I am 95% certain that it is not a fuel smoke. Every thing I can think of points toward a lean motor. It wants to surge, even at idle. Hold the throttle to 2000 and it will surge. If you pull the brake booster hose off, the motor doesnt pick up like normal. It slows and starts stumbling. If you put your hand ever so slightly over the choke tower the rpm will go up just a hair. All of which I have read to be a sign of a lean condition.

Right now Im fixing to pull the wires out of the IFR and go back through the idle mixture screws.

Whenever I get the opportunity Im going to put another carb on it just to be certain. But I just dont see that being the problem.

Thanks for all the help. I will keep posting updates if I ever figure this thing out. Right now Im saying it is valve guides, but Im not giving up yet.

Re: Help with rich smokey idle
 

I do have one quick question for anybody that reads this.

At an idle, if the choke is completely open, the floats are right, and assuming everything is set right, If you were to screw the idle mixture screws all the way in, that will lean the motor out and it will die. Correct?

If that is true, if you screw the idle mixture screws in to the point (just under 1/2 from closed) that the motor is struggling to stay running, and the smoke is unaffected, then it cant be fuel related right?

Am I crazy? Am I forgetting something? Makes sense to me. It has to be valve guides or seals. Doesnt it?

Re: Help with rich smokey idle
 

You say you have 8.5 powervalves, but I thought in the holley tuning sticky, that once you get the "burn your eyes stage" back down a size in powervalve. Put a different carburetor on the if nothing else to see if it's still doing it.

Re: Help with rich smokey idle
 

yes it does say that. But according to my vac gauge it is pulling 14" at idle.

But I am going to try a different power valve just to be certain. I'll probably try that this weekend. I might grab a 2.5 even though I know that is way too low just check. Just anything to make sure that it is not opening. I might get one of those plugs just to check it. *Again, I will not leave a 2.5 or a plug in. This is just to see if my problem is in the power valve circuit*

And yes the next time I get the opportunity to put another carb on it Im going to. I might try to put the 650 DP from my s10 on it this weekend to see what it does.

Re: Help with rich smokey idle
 

The PV should not really affect the idle fuel. Even if it opened low (say a 2.5 power valve), it shouldn't pull any fuel through the boosters...or very minimal amount. However, it could be leaking fuel into the carb. In the end, it sounds like you have an oil problem, not a gas problem. Your stumble sounds like a lean stumble. When you turn the idle air screws in, the car should try to stumble and die (because of being too lean). How do fresh plugs look after idling a while?

I suggested trying a straight 30w oil...I meant 30w not 10w-30. 10w-30 is still a pretty thin oil. I should have been more clear. Trying a different carb is a good suggestion, but I doubt you will find anything there.

Re: Help with rich smokey idle
 

Yeah I mistook what you meant. I assumed wrong. Next oil change I'll go straight 30w.

Im glad you came in here about the PV. I dont think it is it. Everytime I have it apart I have checked it and it is dry on the backside and still holds a vacuum.

And thanks for the confirmation on screwing in the idle screws. I figured if it was so lean it wouldnt run and it continued to smoke then it has to be oil.

For now Im going to continue to drive it on occasion and see how it goes. When I get a chance Im going to swap carbs and do a compression check. But Im already considering pulling the motor this winter and going through it. Keeping the same cam and just refreshing everything. (Might go 383 while I have it out, undecided)

Thanks for the help.

Oh and the last plugs I put in new looked almost like clean plugs when they came out after idling for 2 minutes at temp. But that was just the front cylinders. Im beginning to wonder what I will find if I pull all of them. Which I will do when I have the compression tester with me.

Re: Help with rich smokey idle
 

If it is just the valve seals, you can replace them with the motor in the car. I've done it several times. It isn't a big deal. If it is the rings...that's a different story! There is also the chance that it is an intake gasket. Intake gasket allowing oil to be pulled into the #8 cylinder is what killed my current motor. Seven cylinders look perfect and #8 detonated and blew off part of the piston top. I had been seeing oil on the #8 plug previously to this, but no signs of detonation.

Re: Help with rich smokey idle
 

yeah I have debated on the seals.

I put new seals in when I swapped cams. Of course the way I done it was alittle different. I went by what I heard would work with the combination. I am second guessing on the seals I used. Im wondering if they just couldnt hold up in this case or if they wore out, popped up, etc.

I really need to pull all of the plugs and check them. I might do that this weekend if I get a chance. Maybe then I'll be able to tell alittle more.

Thanks for the help. I'll post up whenever I can find out anymore.

****Update 5-27-14: It has been awhile, but finally got around to replacing the valve seals. Solved my smoking issues.*****