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Discussion Starter · #1 ·
Hi guys,

I've done google searches of the site as well as brickboard and turbobricks, but haven't found anything that's helped yet...

I'm at my own wits end here and hoping to draw from the collective knowledge. I've done a ton of reading on the SU's, as well as a good amount of fiddling.

I've been trying to get my car to pass emissions so I can put full insurance on it, but it's not wanting to cooperate at idle. Specifically, the HC at idle are WAY above allowable.

The idle itself is rough, seems like it's missing, and it definitely hunts in the RPMS. When driving and under load the car behaves normally with no detonation, hesitation or loss of power. The only "rolling" problem is that the car has wanted to stall when coming to a stop at an intersection. With the tune it has it's ok idling in the lot (albeit rough, missing and hunting) but when pulling up to a light and braking it just continues to fall to 0 RPM.

I've done the following work to try to solve the rough and missing idle :

1) New points, gapped.
2) New Cap + rotor
3) New plug wires
4) New plugs
5) New PCV valve
6) Cleaned oil traps before PCV and off valve cover
7) New floats, float valves, jets in the carbs
8) Valve clearance adjusted (.016 and .018 go, no-go as per factory manual)
9) Compression test (all cylinders read ~155 (low...but expected))


I've followed the various SU tuning recommendations (lean jets all the way, back off 12 flats, balance airflow, adjust mixture (no colortune, just idle speed from lifting dashpot), adjust idle) but nothing is giving the idle quality I require.

The new PCV valve "rattles" a lot, as if it's constantly opening and closing at idle. Should this be happening? It's in the same (proper?) direction as the one I took out. Is it possible to bypass by directing down a dolphins throat and plugging intake orifice?

Any help? Emissions in all other regards were spot on, except for HC at idle.

Thanks!!
 

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The PCV valve should not rattle, and you may have the wrong one. The correct one is NAPA/Echlin 2-9280 or equivalent.Check that first.

Secondly, I've never found lifting the dashpots to be useful in any way. Adjust the mixture for the smoothest and fastest idle, readjusting the idle speed as needed.
 

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Discussion Starter · #4 ·
Bad fuel filter?
What psi is the pump putting out?
I haven't put a gauge on the fuel line, but it's enough to spew fuel out of the float bowls with the carbs super lean and idle super low. Good power at speed suggests it's not a fuel pressure issue either.
 

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Discussion Starter · #5 ·
The PCV valve should not rattle, and you may have the wrong one. The correct one is NAPA/Echlin 2-9280 or equivalent.Check that first.

Secondly, I've never found lifting the dashpots to be useful in any way. Adjust the mixture for the smoothest and fastest idle, readjusting the idle speed as needed.
I'll see if I can hit a NAPA later in the day and get that part. The one on it now was the one recommended by Lordco, a FRAM part, but it's all they had.
 

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Hi guys,

I've done google searches of the site as well as brickboard and turbobricks, but haven't found anything that's helped yet...

I'm at my own wits end here and hoping to draw from the collective knowledge. I've done a ton of reading on the SU's, as well as a good amount of fiddling.

I've been trying to get my car to pass emissions so I can put full insurance on it, but it's not wanting to cooperate at idle. Specifically, the HC at idle are WAY above allowable.

The idle itself is rough, seems like it's missing, and it definitely hunts in the RPMS. When driving and under load the car behaves normally with no detonation, hesitation or loss of power. The only "rolling" problem is that the car has wanted to stall when coming to a stop at an intersection. With the tune it has it's ok idling in the lot (albeit rough, missing and hunting) but when pulling up to a light and braking it just continues to fall to 0 RPM.

I've done the following work to try to solve the rough and missing idle :

1) New points, gapped.
2) New Cap + rotor
3) New plug wires
4) New plugs
5) New PCV valve
6) Cleaned oil traps before PCV and off valve cover
7) New floats, float valves, jets in the carbs
8) Valve clearance adjusted (.016 and .018 go, no-go as per factory manual)
9) Compression test (all cylinders read ~155 (low...but expected))


I've followed the various SU tuning recommendations (lean jets all the way, back off 12 flats, balance airflow, adjust mixture (no colortune, just idle speed from lifting dashpot), adjust idle) but nothing is giving the idle quality I require.

The new PCV valve "rattles" a lot, as if it's constantly opening and closing at idle. Should this be happening? It's in the same (proper?) direction as the one I took out. Is it possible to bypass by directing down a dolphins throat and plugging intake orifice?

Any help? Emissions in all other regards were spot on, except for HC at idle.

Thanks!!
Looking through your other posts a few questions...

Does the car have the original coil, shielded cable and ignition switch?

Were any of the old spark plugs fouled with oil/gunk? Which cylinders if any?

Was the old PCV valve gunked up?

Did the new ignition contact set come with the correct-application condenser?

When you installed the new carb jets did you check for bent needles? Center the jets? Correct needles?

Are the floats correctly adjusted? Do the carbs leak at idle? Is the tailpipe wet after extended cold idle?

The rough/missing idle needs to be fixed before another HC test.

Your '66 B18B should not have a vacuum retard on the distributor but if so plug everything so associated.

At warm idle temporarily disconnect/plug each vacuum connection one-at-a-time and note any idle change. We are looking for problems causing a possible erratic supply of intake air.

Be sure the air filters are not mounted USD.

As to the "rattling" PCV valve - that is the spring-loaded plunger clapping open and shut as it responds to pressure changes from one direction only. This means that the PCV system must be correctly routed...

http://www.sw-em.com/pcv_b18_carbs.jpg

Note that on the B18 with twin SU HS6 carbs the PCV system gets fresh air from the front air filter.

Looking at the correct PCV valve...

http://www.oreillyauto.com/site/c/d...ck=Search_02180_1493490_-1&pt=02180&ppt=C0023

...and clicking on the pic we see the arrow showing the direction of flow which shows that the arrow should be pointing "UP" for your B18 PCV system.

George Dill
 

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Discussion Starter · #7 ·
Looking through your other posts a few questions...

Does the car have the original coil, shielded cable and ignition switch?
Coil looks original...The type that's bolted on to the firewall drivers side. Original ignition switch. If you're referencing the original cable from switch to coil, I believe so.

Were any of the old spark plugs fouled with oil/gunk? Which cylinders if any?
Spark plugs read as they should. Greyish brown on all 4 cylinders

Was the old PCV valve gunked up?
Old PCV valve seemed intact, not gunked up. Today I cleaned it and reinstalled. It has an arrow that says "manifold" so it's in the right way

Did the new ignition contact set come with the correct-application condenser?
Old condenser in the Dizzy

When you installed the new carb jets did you check for bent needles? Center the jets? Correct needles?
Needles are true. Jets are centered, and the slides make a satisfying CLUNK when dropped with no resistance

Are the floats correctly adjusted? Do the carbs leak at idle? Is the tailpipe wet after extended cold idle?
Floats are in spec, carbs do not leak at idle. Tailpipe is dry

The rough/missing idle needs to be fixed before another HC test.

Your '66 B18B should not have a vacuum retard on the distributor but if so plug everything so associated.
No vacuum, just the centrifugal

At warm idle temporarily disconnect/plug each vacuum connection one-at-a-time and note any idle change. We are looking for problems causing a possible erratic supply of intake air.
There is one vacuum line off of the manifold only, which T's off towards the PCV, and one towards the brake servo. Blocking either caused no changes in idle quality.

Be sure the air filters are not mounted USD.

As to the "rattling" PCV valve - that is the spring-loaded plunger clapping open and shut as it responds to pressure changes from one direction only. This means that the PCV system must be correctly routed...

http://www.sw-em.com/pcv_b18_carbs.jpg

Note that on the B18 with twin SU HS6 carbs the PCV system gets fresh air from the front air filter.

Looking at the correct PCV valve...

http://www.oreillyauto.com/site/c/d...ck=Search_02180_1493490_-1&pt=02180&ppt=C0023

...and clicking on the pic we see the arrow showing the direction of flow which shows that the arrow should be pointing "UP" for your B18 PCV system.

George Dill
Some more info :

1) Port on top of valve cover consistently blows air outwards at any engine speed, never has vacuum. Unsure of whether this is normal, although I think since it's routed to the air cleaner it in theory should see vacuum at some point... Could this point to a valve seal or other valvetrain problem? I could probably rig up some sort of a compressed air leak fitting for the sparkplug to see if airs going past the rings or the valves.

2)All vacuum hoses are leak tested and ok.

3) Manifold vacuum port is the open (3/8" hole ) so PCV is necessary. If I plug this and retune, is it possible to eliminate the PCV from the equation? Visual inspection of emissions equipment is unnecessary in my area, I just need to pass the sniffer.

4) I haven't tested the intake manifold or carbs themselves with starting fluid to determine if they have leaks (cracks, worn out bushings). The carb throttle plate shafts have some play, but not more than I would expect for a 40+ year old car. I don't want to get into rebushing or reaming them since this motor is going to be replaced by a b5234t3 eventually. Is it possible that a small throttle shaft leak could cause this much havok?

Thanks for the help, we'll get this eventually...
 

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If the oil filler cap port is blowing out at all engine speeds then compression elements are escaping into the valve cover. Improper ignition timing may also cause a high HC reading.

Since your goal is to pass the HC smog sniff it may be possible to temporarily block all intake air except that passing through the air filters. No need to remove stuff just plug the hoses and push them back on the fittings.

At warm idle quickly operate the chock handle fully out then fully in. Use one finger to press upward on each jet body under the carbs. If either/both jets move any amount the idle function is poococky. Temporarily remove the choke cables from the carbs and adjust the choke cam screw well away from the cam.

Before fine-tuning the carbs be certain that the linkage acts on each carb the exact manner and amount.

At warm idle (air cleaners removed) adjust the idle screws from no action to sufficient engagement causing an idle of about 800rpm with both idle screws having been turned the same amount of turns. Adjust the front carb mixture nut "rich" until the engine just begins to stumble then "lean" to stumble then back toward "rich" for the smoothest/fastest idle. Repeat for rear carb. You may need to repeat this for each carb until best idle is obtained. Now adjust each idle screw the same amount to 800-1000rpm idle. Very lean carbs will add to the high HC readings.

If the car continues to idle roughly and tends to die at stop the carb throttle shafts may be too far worn to allow low-HC operation.

George Dill

http://www.smogtips.com/failed-high-hydrocarbons-HC.cfm
 

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You may have a vacuum leak from the brake booster. This is a very easy test to confirm. Just disconnect the brake booster vacuum and drive the car.
 

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Did you really just suggest disconnecting brake system components and going for a drive?
Please be kind to Dimitri - he knows the brakes will still work ok with the booster temporarilly disconnected (if the car has a booster).

Thanks.

George Dill
 

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Discussion Starter · #12 ·
I've tried blocking off the brake servo vacuum line to no effect...Still has poorer idle quality. I drove around with manual brakes a couple times...no problem. It was an aftermarket addition, anyways.

I have a good manometer coming in a day so I'll be able to be 100% sure the carbs are balanced perfectly.

I'm also thinking of doing yet another oilchange, this time with some heavier Dino-oil and an additive for leaky valveguide seals.

In other areas to look at...I've timed the car @ 18 BTDC as per the service manual...I seem to get better Idle quality with it advanced farther, around 25-30 BTDC. At that point though I'm worried about detonation at speed once the advance kicks in. I know a lot of people don't use a gun to time, and just go by the feel of spinning the dizzy, but that's not exactly something that's translatable across the net.

I also found a condenser, which I'll install sometime tomorrow.

I'm going to borrow my shop neighbors 4 gas analyzer so I don't have to spend money mucking about guessing if I'll pass.
 

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where in the world are you that a 1966 car still has to pass emissions?!


If it's a one time thing you could just retrofit a hidden SAS pump into the exhaust. Basically just an airpump that pumps fresh air into the exhaust to mix with the gasses. It was used on the 1998+ cars by volvo to cheat emissions :p
 

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Discussion Starter · #14 ·
where in the world are you that a 1966 car still has to pass emissions?!


If it's a one time thing you could just retrofit a hidden SAS pump into the exhaust. Basically just an airpump that pumps fresh air into the exhaust to mix with the gasses. It was used on the 1998+ cars by volvo to cheat emissions :p
I'm in Vancouver, BC.

Apparently they're nixing emissions testing in 2014 since it costs so much money to run and has very little effect since most cars on the road are newer and low polluters. They say they're going to turn their attention to commercial and heavy vehicles.

Picked up new oil and "Rislone" additive. Basicly a goop-ifyer that cuts down on valve noise and oil consumption... Maybe it'll help the valve seals...
 

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If you're worried about gunk, valve seals and such, I'd highly suggest seafoam...stuff works wonders. Put in Oil, drive 50-100 miles, change oil. You can put it in your gas too as well as fog the intake/vac system with it to clear up gunk in there too. Plus it's less then 10bucks a bottle.
 

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Some people have problem hearing engine knock. if your hearing is fine, don't be afraid of it. Just advance, then take it on the highway and go flat out. If you can't hear knock, you are fine. In fact, if that helps your idle and the car still knocks, you can retard the timing after you pass your emissions test. In fact, you can even use some octane booster temporarily so that you can live with your over-advanced timing.

BTW, this is the best way to set your timing. The manufacturers back then used a bit of a conservative timing setup, to ensure no detonation when the engine accumulated deposits (lot's of interesting old SAE papers on that). Modern gasoline has additives that clean up these deposits much better than back then. So, as the engine wears you may have different optimums, and also the optimum can change based on the octane of the fuel you use.

On the 440's the harmonic balancer sometimes can rotate, so that the read out from the timing light is shifted. I wonder if this can happen on a B18 ...
 

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Discussion Starter · #17 ·
If you're worried about gunk, valve seals and such, I'd highly suggest seafoam...stuff works wonders. Put in Oil, drive 50-100 miles, change oil. You can put it in your gas too as well as fog the intake/vac system with it to clear up gunk in there too. Plus it's less then 10bucks a bottle.
Funny, I actually DID seafoam the car (water+seafoam into intake) before this. Hopefully it didn't break away some beneficially sealing sludge. I'll probably dump the rest of the can into the oil and blast around the highway for a bit before doing another change.
 

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Discussion Starter · #18 ·
Some people have problem hearing engine knock. if your hearing is fine, don't be afraid of it. Just advance, then take it on the highway and go flat out. If you can't hear knock, you are fine. In fact, if that helps your idle and the car still knocks, you can retard the timing after you pass your emissions test. In fact, you can even use some octane booster temporarily so that you can live with your over-advanced timing.

BTW, this is the best way to set your timing. The manufacturers back then used a bit of a conservative timing setup, to ensure no detonation when the engine accumulated deposits (lot's of interesting old SAE papers on that). Modern gasoline has additives that clean up these deposits much better than back then. So, as the engine wears you may have different optimums, and also the optimum can change based on the octane of the fuel you use.

On the 440's the harmonic balancer sometimes can rotate, so that the read out from the timing light is shifted. I wonder if this can happen on a B18 ...
I actually have a pair of "det cans" that make hearing such things easy. I get nervous though when handing the wheel over to the goons at the testing facility...the way they shift...I swear some of them can't actually drive standard.
 

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Discussion Starter · #19 ·
I think as a last resort I may try E85 or a high mixture of acetone (which I buy by the pail for fiberglass) in the fuel. I know in some jurisdictions they'll fail a car running E85 without approval, but here they just care about the gases out the pipe.
 

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Please be kind to Dimitri - he knows the brakes will still work ok with the booster temporarilly disconnected (if the car has a booster).

Thanks.

George Dill
Sorry.... Guess I've slipped into the litigious mindset I've spent so many years chastising! :facepalm:
 
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