PeterZ

Make that $.06. I agree, smoke at start-up = valve stem seal problem. Smoke on decel only is probably an oil ring problem. Compression or cylinder leakage tests may not show any problems because you are testing mostly the compression ring. The increased manifold vacuum on decel will pull oil past the control rings and you see the smoke. Like HCT I recommend checking spark plugs. Stem seals are cheap and easy but sounds like you gotta go deeper. If the engine is really old the oil drain holes inside the piston can plug up with carbon and sludge. Also, an excessively rich fuel system can wash the oil film from your cylinder walls and speed up wear. As a side comment I recommend against these 5 minute engine flush chemicals for similar lubrication issues. By the way, are the engine crankcase vent hoses and baffles in good shape and not puddling an accumulation of breather oil?

I've been gone for a week so I'll jump in late too. We used to pin the cracks (in the '80s) if they are in cast iron. It's very old fashioned but was a good fix even at the seats. Almost every machine shop did them. I've been out of the business for a while but I've only welded aluminum heads and fixed cast heads with the tapered pins.

I use a test light in series with the battery cable. Mine will glow if there's more than .1 amp drain; enough to cause starting problems after a few days. A seat-belt buzzer in series will help if you're dash diving and can't keep looking at the meter (same as dmyntti). I agree to use care to not blow the internal meter fuse. (Start with the biggest setting first.) P.S. Don't forget to look for non-fused items like alternators, cig lighter, starter solenoid, etc.

"14. Long separated by cruel fate, the star-crossed lovers raced across the grassy field toward each other like two freight trains, one having left Cleveland at 6:36 p.m. traveling at 55 mph, the other from Topeka at 4:19 p.m. at a speed of 35 mph." I'm taking a morning physics class before work. This one still has me laughing. If I knew the mass of each train I could tell you the time it takes to convert apples to oranges.

Not much to go on but I'll bite. Since you adjusted valves and run good fuel you seem to think it is an internal noise not related to ignition. If you can duplicate the noise in neutral by lighlty "blipping" the throttle try looking for one of two things: Cancel ingition to one cylinder at a time by shorting the ignition wire through a test light (you need to give a place for the spark to go) and blipping the throttle to duplicate the noise. If the problem goes away you have the found the cylinder with possibly a bad rod bearing. If the noise doubles you found the cylinder with a worn wrist pin bushing. Done anything odd recently like road race one quart low on oil? Of course, I could have rocks in my head or you could have rocks in the exhaust like a catalytic converter that destroyed itself from leaded fuel. What is the car?

As the friction material wears the diaphram spring in the pressure plate changes it's position and so the release arm must work in improper working angles. As clutches wear the clutch pedal engagement gets higher and higher until it is up under the dash. The dis-engagement point also gets lower and lower until there's not enough floorboard for the travel required and the car keeps going when you want to idle in gear. Is this the case? That's probably normal wear and it's long overdue for a clutch. The difficulty in selecting gears is likely your syncros wearing because they are working against a clutch that isn't disengaging. They might soon tell you that they are worn as well by the grinding noises during shifting. Some cars won't slip the clutch when they are worn. A BMW 320I will slip to the point where the car won't move but the same year 535 will keep working until there's nothing left of the disc. It's all in the lever ratios as parts wear. Check your release lever pivot points as well. Collectindust240Z is correct that other wear items can cause release point problems and you don't want to go in there twice. Some release arms pivot on a nylon pivot ball that may be all gone from the amount of friction material dust and many years of service.

I agree with the above two comments. There are many things that can cause your woes. Still I have to throw my two cents in. Popping through the intake may be due to a too-lean air/fuel ratio but that shouldn't make it suddenly die. While you're checking things (basics first!) you might want to check the resistance of the temp sensor. It is an NTC sensor meaning that the resistance goes down when the temp goes up. Rough numbers: 3,000 ohms cold and 300 ohms hot. Adusting the AFM for better driveability is easy but you have to be sure everything else is good. Have fun.

I love relays. I'll check Pete P's writeup too. I put my brake lights and rear turn signals on them. No more smoke signals from the dashboard while waiting in turn lanes and the blinkers work every time. I think relays would help the slow wiper problem too but haven't tested for power losses in wiper system yet.

A agree with Tim that the fluids are compatible. I got out of BMW repairs to go to a Datsun shop in '95 but did a lot of trans rebuilds on the ZF 4HP22/ET automatics until then. The newer ones are not supposed to have fluid changes! There's no dipstick or filler plugs.

I don't think a longer rod will fix the problem correctly. With the release arm not working through the 90 angle the lever ratio is not correct; it will take much more travel to get the pressure plate to release and engage. You probably don't have enough throw with the slave cylinder to cover the misalignment of the release arm. When you say breaking the slave I'm assuming the piston is popping out of the end, correct. If so that is probably because the slave needs to travel more to make up for the ratio change of the misaligned arm.

There are at least two different depths (or lengths) of release bearing collars. You might have the shorter collar installed. This could cause the release arm and bearing to move closer to the pressure plate drastically effecting the working angles of the release arm. The arm needs to be working through an angle 90 degrees to the input shaft. If the arm is already past the 90 degree angle there isn't enough movement to propely actuate the pressure plate. You might notice you need the full travel of the pedal to get the clutch to fully engage/disengage. Lengthening the pushrod will help by moving the slave cyl piston away from the end of the bore. If the angles are correct you may need to verify proper diameter master and slave cylinder bore sizes. Most often I've found customer cars to have the short release bearing collar when they would come in with trans swap clutch problems. PS you can usually see if the angle of the arm is already past midpoint of 90 degrees by sighting the line through the slave pivot, arm pivot and the release bearing contact.

In response to a 240 Z running one quart low I would have to say the danger is with respect to the cornering forces. A friend and I traded race cars for a Sears Point race and I smoked a bearing to his car during qualifying (second track session). There was nothing noticeable from the gauges. I was doing faster lap times than he was and he said he always ran a quart low. My goof for not checking before belting in. Dave Rebello was quite amused when we brought the engine back to him...Baffles are great if the rules allow, pressure tank (accusump) systems are an easy fix too. IMO one quart less oil is not going to gain you anything but the chance to lighten your wallet.

Again, have you checked camshaft timing? The cam cam be in backwards and still have correct ignition timing unless I've got the wrong engine then I'm sorry for the confusion. Like the Ol' Timer says: go to TDC and check the camshaft timing marks. Check at the piston 'cuz you can't believe the pulley at this point. I had a dampener pulley once that was slipping on the rubber dampener. Every fifteen seconds at idle the ignition timing marks would slip into alignment and then rotate away. Totally weird. Just from the pulley load from the alternator. Verify piston TDC, the camshaft timing marks and also for split overlap between the intake and exhaust valves if you want to go nuts. Then go check for things like the shop rag stuck in the downpipe. You can tell that by feeling for a pulse at the tailpipe. Plugges exhausts have a real smooth air flow. That's another story...

I would recommend verify your cam timing. Retarded cam timing will drop intake manifold vacuum and show lower than expected compression readings. Your run-on may be due to the throttle position. I'll bet you raised the idle to kep it running because it had a very low idle. Too much fuel/air with the key off can cause run-on (Just like a poorly set pair of S.U.s). Your ignition turns off with the key so ignition advance would not likely effect run-on unless it was causing high idle speeds or very hot combustion chamber temps.

There's a bulge in the tailhousing where fifth gear lives. The bulge is on the bottom of the trans nearest the intermediate plate. Four speeds have more of a 45 degree angle in that area without the bulge. I agree: try it with a shifter.

I have used them on racing applications mostly. Some customers had them on street cars too and they worked well. It helps if you know what your engine needs in the way of fuel and at what RPM. I profiled needles for customers' street engines by sanding the needles while they were turning in a drill press. One can measure the amount machined and choose where to perform the maching. I got pretty good at it when I worked at a shop that had a good exhaust engine analyzer. Most of the street tweeks were to improve off-idle performance and still be able to shut off the engine without run-on. Others were necessary for big engines with Dave's overbored throttle bodies.

Pumping a fuel injected car's accelerator shouldn't do anything unless there's some airflow/fuel metering problem. You might have some sort of gigantic air leak somewhere or a sticky A/F meter. Questions: Does it run smoothly above 1K RPM. Any smoke when it is blubbering. If so what color.

What I have learned from my time as a mechanic: Steering wheel shakes are from the front suspension (wheel balance) and seat/floorboard vibrations are from drivetrain and rear wheels. Steering shakes that are difficult to find can come from things like: perfectly spin-balanced wheels that don't center properly when bolted to the hub. (You can spin the wheel in the air and see the runout.); The Z cars I have seen like the heavy steel wheels. Many aftermarket aluminum seem to shake more (some sort of centripidal/centrifugal effect) especially if there's any looseness in the steering rack, linkages or the wheels don't center to the hub. I recommend checking steering and suspension with the car on the ground or on the alignment rack. (When the suspension is drooping the bushings and joints can hide wear because the joints are in a different position than when on the ground.) A bad motor maount can effect the driveshaft working angles and certainly cause a driveshaft vibration if it is severe enough. I agree with the others-replace it anyway because it is bad...You can trace driveline vibrations on the lift by carefully removing items one at a time until the vibration goes away. Please tightem the drums to the hubs if testing with the rear wheels off the car. I saw a drum come off in the paddock at Sears Point Raceway; almost took somebody's leg off. Good luck.

Your driveshaft angle will suffer (vibrate) if it doesn't match or "mirror" the differential angle. I don't have links to more info but I'll bet there's more coming from others here. My recommendation is try to measure your angles now so you will know where. You'd really need severe angles for oiling problems to occur. (Nobody drives on totally flat land.)

I suggest you also need to adjust the pushrod lenght at the booster by removing the master cylinder. The pushrod end should have threads and a hex area for adjusting. If the pushrod length is too long because you're missing the spacer, no amount of underdash adjustment will help. Maybe you can make a master-to-booster shim that uses as much of the master cylinder mounting threads as possible to creats more space between the pushrod and the master. Again, when this is right you can test the effects by being able to push the caliper piston into the bore (and pushing the brake fluid into the reservoir). You probably can't do that now with your current adjustment.

Make that 4 votes. You will know when you have enough clearance for the pushord when you can push the caliper pistons back into the bore and the displaced fluid backfills the reservior. Your piston is blocking off the transfer port and there's only one place for the pressure of heated brake fluid to go.

Why did you replce the U joints and did they squeak before replacement? Driveshaft u-joints will squeak about 3-4 times wheel rotation speed due to the differentail ratio. They will increase frequency quickly as you accelerate from a stop. Like 80LT1 before you may have bent something if you used a big hammer. Did you move the u-joint cup back away from the u-joint cross after installation? If there's preload inside the cup against the cross you could hear noises after a few miles when the metal to metal dries up the grease and the parts turn blue. You'd have to take the cups back out to see that. Not recommended is your install is correct. A squeak on accel/decel maybe halfshaft splines. They make noise once when loaded in a new direction. Depends on when you hear the noise and what you are doing to make the noise. I've seen dry door jambs make noises on accel especially with big motors.

I recommend check basics-(Fuel, compression and spark at the right time) You didn't change anything for compression so: Verify fuel pressure. An ECU means fuel injected car 35-45 PSI fuel pressure. + side of coil should be batt voltage during cranking, neg side of coil should pulse (with a test light). If no batt voltage at coil pos. there is probably an interesting elecdtrical problem. If there's no pulse at coil neg (but coil + is OK) there's most likely a dist problem. You worked on the fuel pump electrical, Check associated electrics in that area too. Where are you checking for spark and how are you checking?

So true about white smoke. Did this car overheat about six months prior? There are many very good ways to remove broken head bolts from the engine block without doing damage to anything. I got a job offer for doing a head bolt repair for a friend's shop. Hopefully you don't have a head gasket problem and it is an external coolant loss.

Another tip: Take off the oil filler cap and look at the inside of the cap. If it looks like a used baby diaper or some sort of bad salad dressing you have the signs of coolant getting into the combustion chamber and past the rings into the oil. The water vapor gets trapped at the highest spot, the underside of the valve cover and may not show in the oil pan. Small coolant leaks probably won't show up in compression or cylinder leakage but it is a good indicator of the wear on the engine. Good luck. P.S. Coolant smells sweet in the exhaust and burns white, oil burns blue and, of course, gas shows black in the exhaust.