intake manifold plenum gasket replaced; pcv valve replaced--- still problems

Disconnecting the battery won't help. You need to run the drive cycle again and see what codes if any pop up and if the idle sorts itself out. Might want to smoke it again too to make sure you didn't introduce another leak.

Drive cycle this morning didn't reveal any codes or pending codes, but EVAP and CAT were still not ready, of course.

Someone mentioned being sure the manifold was tightened down enough as apparently I used torque values for the plastic and not aluminum like I have. Did that and did the drive test.

short term trims seem pretty good, staying in single digits, under +/-5 most of the time (mainly 0 to -5)

long term trims remain around +10; they may briefly go to 12-14 at times but don't stay there long; or they may drop below 10 at certain times.... definitely not a steady number.

If I increase RPM to 2500 and check trims, short term doesn't change; long term drops slightly to 5-7 or so.

My guess would be probably as you suggested, still a slight leak somewhere so may bring out the smoker later today. These numbers though are quite a lot better than the initial 20+ I was getting all the time. I think it would now pass inspection where it is, but I won't know for sure until cat and evap show up.

One question, when I replaced the pcv valve, should I have wiped/ dipped the valve in brake fluid? I seem to remember someone mentioning wiping around the outside of the valve with brake fluid. I didn't do this.

Ok, ran the smoke test again. No additional smoke detected since valve/ plenum gasket replacement. I did remove the pcv and wiped the outside of it with brake fluid, then reinserted.

No change in trims, roughly 0 to -5 short, around 10 long but sometimes drops to 7 and then as high as 14.

Not sure where to go next, but I think I can rule out vacuum.

This is not an alarming condition.

Your issue with the inspection now is that you have two Readiness Monitors that are not completed. Some cars can be tested with two monitors still running, and some cars can only be tested with one. The difference being the age of the car, I think. You can call the smog shop and tell them that you had the Check Engine light, and that you cured the issue and the light, but there are still two monitors running and then ask if they will test in this condition.

I've not heard of this, but if I was going to guess on this I'd guess that the purpose is that when the fluid dries it forms a seal between the valve and the grommet it fits into. Think of it as gluing the PCV into place. That's just a guess though.

I would pull that PCV again and clean as much of that brake fluid off as you can. Brake fluid will often cause rubber or rubber-like grommets to swell and crack. For things like that (ease of insertion if it seems really tight), I would recommend a couple of drops of transmission fluid, wiped evenly around the grommet and hole.

Ok, this seems kind of odd to me, but maybe not you guys. Did the drive cycle this morning and no codes revealed, but LT and ST levels not quite normal, esp LT. Took a trip this afternoon and upon returning home, now I/M readiness fine for everything except EVAP. The unit is actually giving me a green check mark. I check LT/ST and they seem even better now with the LT varying from 3-7 and seldom reaching 10.

Is it possible that the car's computer, whatever you call it, had to re-evaluate and correct everything over a period of time after I had done the repairs earlier? I thought I had cleared the data from the memory upon startup, but maybe not

or

maybe it was waiting for the CAT to be fine before reducing trims?

The bottom line is that everything seems better as of this afternoon. Once EVAP clears, I'll take it through inspection early next week. Maybe I still have some fuel to burn before EVAP will clear as I just filled the car yesterday with Premium. It's still 90% full I'd say.

Is the aforementioned a feasible conclusion, or am I building false expectations?

Brake fluid is generally safe for rubber - that's what it is designed for. Don't sweat the small stuff And if the CEL doesn't come on after the monitors have set, it should pass. Does it run well??? Again, don't sweat the small stuff.

It's a lubrication thing. With a bit of brake fluid on the rubber it slips in like butter. Personally, I just put an oily finger on the end of the PCV valve and pop it in. The seal is designed for oil, after all. Brake fluid shouldn't hurt anything though, as it is designed to keep rubber supple enough to seal brake systems.

The monitor for the cat needs to set before accurate fuel trims can be optained and the block learn can work. Like I said, don't sweat the small stuff. Your evap monitor will only set during the first 30 minutes of driving with the tank between 1/4 and 3/4 full. with IAT between 40 and 100F. Virtually impossible to set an evap monitor in the dead of winter. With only the evap not set, they can test and it should pass.

One, you can take it for a smog check now if you want to. You only have one monitor running, and they will test in this condition. The might test with two monitors, but they will certainly test with only one of them.

Two, you are burning far too many brain cells. I do not expect the long and short term trims to be flat. They have a range and they can move freely within that range.

Three, I do not think your car gets any benefit from using premium fuel. This is a complete waste of money. If you have a car that calls for premium but you give it regular, the computer will detect the knock (pre-ignition) that results and it will retard the timing to prevent it. Performance will suffer, although many people report that they do not notice the degradation. You have to run several tanks of regular and log the Cost Per Mile -- price of gas divided by the MPG -- and then run several tanks of premium and repeat the same calculation. The lower cost per mile is the one you want.

Generally, if you drive about 15k miles per year you will find that premium -- if this is what your car wants -- will give the lower cost per mile because premium will give better miles per gallon, and you will save about $150 per year. Remember, if your car calls for Premium but you use Regular then the engine will detune itself and your mileage goes down -- using the right grade of gas puts the engine tune back where it belongs and you get better mileage and a lower cost per mile. If your car wants regular, then using premium will give you no benefits, the cost per mile should go up because the fuel costs is more but your mileage is the same.

You still have not caught on to why it was recommended to use Premium for troubleshooting. Too much ethanol can result in an engine running too lean and at least here in Canada Shell premium has NO ETHANOL. In many places the hooch goes in the regular gas at 5%, and none in Premium, giving E2.5 for the mid premium.

He doesn't need to run premium full time. Wasn't recommended either. It won't hurt, as there is virtually no difference in burn speed or energy density related to octane rating.

Ok, guys, I guess that was a false alarm about the trims dropping even further. Tonight, long term was showing 8-14 or so, only short term stays nearly at 0 now.

As long as I'm still good on everything except EVAP, I'm going to get it inspected early this coming week.

Afterwards, if I have the time, I'd still like to explore why the long terms are running around the +10 range.

Too many brain cells... yes, I tend to go overboard with things and that's why I need to back off from this for a while after it passes.

I'm thankful that the smoke tester quickly revealed the cracked valve boot; nothing else would, not propane, sprayed water, etc.

BTW, Clare, it's running fine. I didn't even notice much difference when the pcv boot was cracked. Without the light coming on, I would have never noticed any difference. That's why I thought surely it was bad gas at it had been in the past, but the code reader quickly ended that theory.

You had mentioned the bad idle after putting the manifold back on and I just wanted to be sure that had solved itself.

Seems ok. When I first reassembled, I thought it was going to stall once or twice, but it has smoothed out considerably.

Inspection today and the car PASSED! Very satisfied.

Before I took it for inspection, I decided to take a graphical look at the O2 sensors on the scanner. Sensor 1 seems to respond normally, smooth wave, then becomes compressed when I go to 2500 RPM. Sensor 2 is not showing the same behavior, very erratic wave and voltage not changing much. Not sure if this was because the car wasn't warmed up long enough or not. It's 40 degrees here, so maybe I need to let it warm up longer first, but I do want to check this out tomorrow. I can't save the graphs, but it would be easy to video them and Utube them or similar.

Alright, I drove the car anyway for over an hour and rechecked O2 sensor data. Sensor 1 is varying from about 0 to 0.7, sensor 2 seems to stay around 0.7, not varying much at all, maybe 0.1 either way but basically steady. No change with sensor 2 at 2500 RPM either. Is this sensor bad? It might explain why LTFT is still around 10-15%.

The second sensor is NOT supposed to move like the first one. It is checking the outlet of the converter. If the converter is working properly the ouplet is almost steady. The input goes rich and lean around stoich to fire the converter, with the AVERAGE being stoich.

You are throwing too many brain cells at a simple job. It's not rocket science. You got your pass -don't keeplooking for trouble!!!

Is your IAT reading accurately? If it is showing too warm the O2 sensor will ask for more fuel than the map calls for - your LTFT will go up. Again, too much ethanol in the fuel will also cause LTFT to go up, becuse ethanol is only half as "rich" as gasoline. Also, you could have dirty/restricted injectors (not dribbling). If they have not been cleaned in some time, a good dose of a good injector cleaner may do the trick. If the trim doesn't change at 2500 RPM from idle, I doubt it is a leak situation. The second O2 sensor has virtually no input to fueling strategy, so very unlikely you have an O2 sensor problem - Bouncing 0-.7volts on sensor #1 means the sensoris working and the ECM is responding. Sensor #2 staying close to .7 volts means the cat is working. Aither way, winter driving, only a few miles since correcting the lean condition, LTFT a bit higher than optimum is not necessarily a problem. Make sure your ignition is right up to snuff too, because a misfire can cause the same problem - but SHOULD throw an OBD2 code.

I think I'd better agree with this (and leave it well enough alone) as I may be starting to get carried away.

One thing I think I definitely need to do though is change out the plugs and wires, way overdue. This is something else I haven't done on a car, so picked up plug sockets and gap adjuster yesterday. Any links you or someone else could provide as to how to go about it with this engine (Vulcan 3.0 OHV) would be welcome!

Oh, and a big, big thanks for being patient with me. I'm a fast leaner. I've learned more about cars in the last week than I ever have before. One thing I realized though is that this experience was only the tip of the iceberg!