Help me get through smog. High HC. RESOLVED! IT PASSED!

[MSmethers]

Been a lurker for a while in anticipation of the upcoming emissions test on my 79 FI CA SuperBeetle. Failed miserably (just plugged into EGA) I do have a thread on TS at the moment regarding a lack of power that speaks to the EGA results towards the end. http://www.thesamba.com/vw/forum/viewtopic.php?t=435898 could be related to the current high emission problems.

The way I understand it, HC is unburned fuel indicating a rich/lean misfire. Usually ignition or vac leak.

Anywooo... onward
HC is way high. 400+ when the limit is 200 idle, 180 cruise. My county isn't using the rolling test yet, just the idle and 2500.
Prior to this test I attempted to adjust AFM per the sticky and driveability improved somewhat. Moving the wiper showed lean condition at both idle and 3000 (rpms increased with the slightest bump) moreso at the high end. AFM adjusters take heed. 1 click on the wiper CCW on the wiper, picked up CO to over 6%, Max is 2% at idle 1.7% at 2500 rpm (can you say gross polluter?) from previous sniff tests. HC was 300 ish with 200/180 limits. Backed out of the smog bay (while the next appointment smogged) and put the wiper back where it was (MARKING THE STARTING POINT IS CRITICAL) Moved the cog spring back where it was too. Pulled it back in, CO was much improved but HC up over 500, WTF?
My smog guy was great, let me leave it on the EGA to try and tune the HC down. Mixture screw netted less CO, down into the 0.2/0.9 range but HC still waaaaay too high. Basically burnt up half a day betweent the DMV (getting a moving permit) and smog station.

Bought the car with most of the FI equipment in a box. The injectors that were with it were all mismatched and since I had no starting point, I scored all new Bosch parts. Injectors, FPR, CSV, AAR, Manifold boots and the thick phenolic manifold gaskets. This all went onto a circa 1967 H case that was supposedly just rebuilt. I put new FI heads on, compression is 135 in 3 cyls and 140 in the fouth. New fuel lines (all), vac hoses (all), gaskets, clutch, gland nut O-ring and rear main, new fuel pump, filter, TSII, plugs, points, condensor, cap, rotor and wires. All components pass the Bentley diagnostics. When I opened the AFM initially (factory sealed) the wiper was adjusted to the full CCW position and siliconed there. Two full cans of GumOut reveal 0 vac leaks. DVDA set at 5 deg ATDC, dwell of 49, Bosch plugs gapped at .028

In fiddling with things last night, I threw a volt meter onto the positive side of the coil and got a reading of 8 volts at an idle. Pulled all the leads and tested between terminals, terminals to HT lead, all withing spec. Reconnected everything and couldn't repeat. 13.5+ volts across the board. Contemplating replacing the coil.

I have an analog wideband O2 sensor/gauge that should show up today or tomorrow so I don't have to waste anymore of the smog shops time than necessary and hope to be able to dial it in close to 14:0 as possible.

Sorry for the windy post, but I'm tired of obsessing over this thing want to get it legal for SWMBO to drive and move on to my next obsesseion.

Any help/suggestions are greatly appreciated.
Marshal

[airkooledchris]

if your still fighting a seemingly odd power issue - what condition is your CAT converter in?

is it brand new?

maybe it's partially failed/clogged and causing both your power and poor HC readings?

[MSmethers]

Thanks for the reply Chris,
Yes, forgot to mention, new cat, muffler and EGR filter.

[airkooledchris]

until you get your AFR tester, make a quick run through all of the basics again just to be sure you don't have to worry about them.

valves, timing, dwell, just re-do the whole lot.

usually when I find myself deep into research on a very very odd issue, something stupid/simple bites me in the ass.

[MSmethers]

I will go over everything again. I've run the valves and ignition settings at minimum 4 times. I can't get away from the feeling it is something simple, but just can't find it. I've gone so far as to completely disassemble the dizzy, clean it thoroughly and lube the pivot point/friction points of the centrifugal and breaker plate, reset dwell and timing. Just did that last night but it doesn't run well enough to see if it changed anything. I need to pull/flip the AFM to get to the wiper/cog but I'm waiting on the 02 sensor/gauge before I tear into that again.
Additionally, I can't find any reference to the small screw on the throttle linkages. I know the idle speed is the large one on the throttle body, but what is the little one for? I do know that if I go more than 1/2 turn or so past just touching, I lose the vac signal to the retard side of the dizzy. I've had the TB off and by the location of the hole in the bore itself, it makes perfect sense. However, with the screw in that far, the speed screw backed all the way out, barely gives me 900 rpm at idle.

[vwlover77]

For what it's worth....

"Elevated hydrocarbon (HC) emissions usually indicate ignition misfire due to fouled spark plugs or a bad plug. But high HC emissions can also be caused by burned exhaust valves (check compression), lean misfire (check for vacuum leaks, low fuel pressure or dirty injectors), or rich fuel conditions (fuel saturated carburetor floats, excessive fuel pressure, leaky injectors).

High carbon monoxide (CO) emissions are a telltale sign of a rich fuel mixture. On older carbureted vehicles, fuel-saturated plastic floats, incorrect float settings, leaky power valves and misadjusted chokes are often responsible for the rich mixture. On newer vehicles with fuel injection, leaky injectors and excessive fuel pressure are possibilities to investigate.

Harder to diagnose are elevated oxides of nitrogen (NOX) emissions. Causes here may include a defective EGR valve, plugged EGR ports in the manifold, over-advanced ignition timing or engine overheating"

Have you checked fuel pressure and fuel pump delivery volume per the Bentley?
Does the engine have a stock camshaft? "Performance" cams can wreak havoc with fuel injection and emissions.

[MSmethers]

Thanks for the reply Don.
The old fuel pump (replaced due to excessive noise and potential reliability issues) pressure was well within spec. 36-38 psi w/no vac supplied to FPR, vac draws it down to 28 or so. Even stabbing the throttle, pressure remained within spec. Volume test (from CSV) revealed 1 liter of fuel in approx 18 seconds. I honestly haven't tested the new pump yet since the overall behavior of the engine did not change.
Injectors are new, but I will pull them and test for leak/spray pattern. Plugs looked good (albeit lean) when I ran the compression test about 1 hr worth of run time prior to EGA.
That my friend, is the one unknown (Camshaft) and one of my first suspicions as well. However, I don't see the PO putting in anything other than stock (cheaper) as his intention was to "flip" the car from the beginning. I'm still on the hunt for OG cam specs. Mainly lift since that is all I can check without R&R and disassembly of engine/pulling oil pump. No idea how to measure LC, overlap, duration etc. I have no issue pulling and replacing the cam IF I knew it to be the problem, but I'd hate to go through all that work just to end up where I am now. Heads are new as are the valves in them. Compression is good in all 4; 135-140.

[Amskeptic]

79 FI CA SuperBeetle.
HC is way high. 400+
Moved the cog spring back where it was
CO was much improved but HC up over 500, WTF?
Mixture screw netted less CO, down into the 0.2/0.9 range but HC still waaaaay too high.

Bought the car with most of the FI equipment in a box.
new Bosch parts all on a circa 1967 H case
new FI heads
compression is 135

When I opened the AFM initially (factory sealed) the wiper was adjusted to the full CCW position and siliconed there.
DVDA set at 5 deg ATDC,

Marshall, you have a little Frankenstein going on here.

Compression ratios were dropped in 1973. Check the bore/stroke for an H 1500 or 1600, and compare to the later FI 1600s. I believe the ratio was dropped primarily through the installation of dished pistons. Do you have flat pistons?

Your HCs can come from misfires as mentioned, but also from fuel contaminated oil and a saturated fuel tank vapor canister from topping off the fuel tank (yeah, from those stupid gas pumps always sneaking past the round number you are shooting for).
Drop plug gaps to .024"
Change the oil.
Block the fuel evaporative canister hose wherever it joins the intake system.
Make sure air filter is clean.

Now for my guess. I am guessing that the retard diaphragm on your DVDA is leaking. At idle, pull the hose from the retard side of the distributor (or from its other end at the carb if it is more convenient). Idle should jump up. If there is no change, that explains your difficulty getting the idle to adjust down to the proper 850-900 rpm, and it means you have adjusted the timing map to a whopping 12* retarded throughout the rev range. You can only adjust to the After TDC specification with a known good retard diaphragm. Otherwise, you must time to 7.5 Before TDC or, better yet, 28* BTDC at 3,000 rpm with hoses off.

If you have an inadvertently retarded timing map (which drops your power down too, by the way) the misfires will HC emit you into the stratosphere.
HTH,
ColinInIndiana

[MSmethers]

Thanks for joining in Colin.
Frankenstein? You have no idea. PO was a real POS and liar to boot. Anyway, accept what cannot be changed. Right?
Since I had the engine out to replace with the proper FI heads, I checked and the pistions are 85.5 and IIRC, flat topped. Any carbon that was on them very easily wiped right off. So I believe that he did put on new 1600 P & Js.
Oil has no smell of gas, not even a hint. I put new oil in with the new heads, but I'll change it again.
Vapor canister is a possibility as I did hook all that up prior to my emissions test. Wasn't on the initial test on the EGA.
Air filter is new.
DVDA retard is in fact pulling advance out of the distributor. After cleaning and lubing, I put the vac pump on and watched it work. The diaphram does bleed down slowly, about 10 mins to go from 10 hg to <5. When the hose is removed (at idle), idle speed jumps up and timing advances to 7.5 degrees. Total advance is approx 42 at 3000 rpm. I do have some doubts in the accuracy of the timing marks on the pulley as it has the early 7.5 and 10 degree notches. Using a small screwdriver I found TDC on 1 and verified the mark made for TDC. Moved 5/16" to the left and marked it for 5 ATDC. 1 3/4" to the right from TDC, marked it for 28. My local Bug man is looking for a correct pulley for me. I'll check the timing again (for the umpteenth time) at 3000 with no hoses as what you are saying makes perfect sense.
PS, I am looking for the proper AJ case to build a motor I know to be fresh. Just gotta get past smog and let the ball and chain drive 'er for a while.

[Amskeptic]

pistons are 85.5 flat topped.
DVDA retard works.
Total advance is approx 42 at 3000 rpm.
gotta get past smog .

Total advance as in "vacuum advance hose still on"?
Vacuum advance doesn't really care what the rpms are.
We need to know "centrifugal advance only" at 3,000 rpm and hell, 4,000 rpm as well, it is about *never exceeding 28** centrifugal.

So anyway, I recommend that you time the engine very conservatively. For an emissions test, we like reasonably retarded (as in a couple of degrees) timing because it demands more air flow per X rpm, this helps dilute the poison.

Can you hear the misfires? Does the timing light show misfire and scatter?
I swear, new parts almost always demand that you check their specifications and construction quality very very carefully. Even a brand new wire set can have a connector resistance out of spec, or a rotor resistance that is unbelievably high. How about freshly "sonically-cleaned" fuel injectors with "flow rate charts! woooo" that have a 50% failure rate, like a customer of mine recently discovered? Do not let "new" throw you.

Think:
HC's > unburned fuel
CO > mixture
NOX > overly hot combustion
(this does not mean the engine necessarily runs hot)
Colin
(don't MAKE me come out there and get you past smog)

[MSmethers]

You're more than welcome to come out. Weather is still beautiful here this time of year. Close to the ocean, lots of wineries and microbreweries!

Yes, as of last night, total timing with vac lines attached is approx 42. Right at 30 with lines detached. 4 ATDC at idle with all lines attached. While on the EGA, I spun the dizzy a few degrees both directions and saw no change in HC.

Cannot hear misfires at all. Only odd thing with timing light is that it speeds up with RPM as expected, but once a certain RPM is reached (2000?) it seems to switch over to every other spark event. But smooth throughout the rpm band.

Just finished dropping the exhaust to install the 02 sensor tomorrow when I get home from work. While it's up in the air, I'm going to run the valves and change the oil. Does it really require a puller to remove the oil pump? I want to pull it to check if cam gear has 3 or 4 rivets. That should tell me whether it is stock or not, right?

While I got you on the hook, what AFR am I shooting for for lowest HC. Both at idle and 2500 rpm? Or is that just an exercise in futility?

[MSmethers]

Does the engine have a stock camshaft? "Performance" cams can wreak havoc with fuel injection and emissions.

You know, in thinking about this, there are 2 potential problems.
1) I don't know if it's stock or aftermarket
B) If this joker used the original 3 rivet (1967 H block) cam, does it have the same profile as the 4 rivet late model style?

So even if it is a stock cam, stock for a carb'd model may be significantly different. From what I'm finding tho, the change to the 4 rivet was 1971 which predated the FI system.

Bottom line is, would a stock 3 rivet cam "wreak havoc" on the FI system and potential HC output?

Thanks for sticking with me on this.

[MSmethers]

Seems I have some issues!

Put the 02 sensor in and where it was set, AFR was above 18.1 (limit of the gauge). With the wiper totally CCW, AFR at idle is 14.6. At 3000 rpm it's 12 ish. Never comes up. Backed off 4 notches on dynamic adjustment to get it to 12. At idle bumping the wiper CW brings RPM up, CCW down. Adjust it to where it stumbles CW, AFR is over 18 again. Acts like a pretty severe vac leak somewhere. Just have no clue where. I've been over everything with carb cleaner multiple times with nothing found.

More symptoms of the wrong cam?

[Amskeptic]

Seems I have some issues!

Put the 02 sensor in and where it was set, AFR was above 18.1 (limit of the gauge). With the wiper totally CCW, AFR at idle is 14.6. At 3000 rpm it's 12 ish. Never comes up. Backed off 4 notches on dynamic adjustment to get it to 12. At idle bumping the wiper CW brings RPM up, CCW down. Adjust it to where it stumbles CW, AFR is over 18 again. Acts like a pretty severe vac leak somewhere. Just have no clue where. I've been over everything with carb cleaner multiple times with nothing found.

More symptoms of the wrong cam?

So I'm a month late in responding . . .

. . . "with the wiper totally CCW" at idle, just doesn't happen. I am discovering that the ECU has a flooding prevention program where it reads the RPM signal against the AFM, and leans out the mixture if you pretend rich with moving the wiper with no corresponding increase in rpm signal.

I am discovering as well, that airflow is critical for getting the mixture dialed in.

The only "default" guaranteed adjustment parameter that works to help us get rid of exploding variables, is to check the fuel ratio at 55 mph in 4th gear under full throttle (use the brakes to maintain the speed for a second). It should be in the range of 12.0-12.7 at sea level. This adjustment must be performed at the wiper.

With the wiper in our default location, you adjust the spring to handle off-throttle mixture and some partial throttle. It needs to be strong enough to shut off the fuel at 3,000 rpm coast (reading at least 17 > )

I swear I shall do a write-upo to update my hopeful and hopelessly naive AFM write-up on theSamba and here.

[MSmethers]

Time flies aye? Time for an update anyway.
Perhaps you misunderstood when I said the wiper was fully CCW. I meant the adjustment was at the CCW limit.
After further reflection and contemplation of my naval and finding the large amount of oil in the plenum, I decided it was time to ditch the "frankenmotor" and find the right case and apply the right parts. I found through the Samba ads a complete, freshly rebuilt FI longblock at what I think was a great deal. Made the drive to pick it up, drove it straight over to my local Dub specialist and had him tear it apart, check over the previous rebuild and address any issues. New rear main, gland nut seal, fresh assembly lube and a few other items, I'm good to go. Got the new engine in and fired up, broke in the cam and adjusted AFR/AFC per the write-up. Running solid at 14.3-14.5 at idle and 2500 rpm (smog test idle speeds). Took it for a quick spin this afternoon and ran like a champ. A little condensation out of the tailpipe as it warmed up. Things are looking up at this point. Just need to get back to the DMV for a new moving permit to drive to the smog shop and see what she blows.
I pulled the AFR gauge off as the wiring was too close to the exhaust and catalytic converter for comfort. I didn't want to drill into any sheet metal as it was never intended to be a permanent install.

Now for the question. Does a new motor with rings not completely sealed/broken in, make a poor emissions test candidate? I'd love to be able to drive the snot out of it for a 100 miles or so prior to, but can't ahem.... legally.