240260280z

Just used Mothers Clay Bay kit to do my 2003 S2000. Turned out nice. Before using the kit, I washed with a strong dish detergent to remove wax then used the clay bar over the detailing spray (lubricant) that came with the kit. Paint feels smooth and shines. (Now I have to touch up paint chips then wax). BTW if you ever thought clay baring was some sort of special art, it ain't, it is easy as washing your hands with a bar of soap. After doing this I wondered if the expensive Mother's kit was worth the $20 so I Googled. Turns out you can buy clay from most hobby/craft shops (even Walmart craft section) and use a spray bottle with mild liquid soap and water or a detailer spray (as a lubricant) to to the same job for 1/10th the price. Reference (CARGUY123 POST IN THIS THREAD) : http://grassrootsmotorsports.com/forum/grm/ever-use-a-clay-bar/1646/page2/

On some thermostat housings, there is a shape to the well under the thermostat where the protrusion has to sit properly. You can measure the temperature of the thermostat opening in a pot of water on the stove with a thermometer in the pot (thermostat and thermometer suspended in water... not on bottom). Also the orifice of some after-market thermostats is often smaller than Nissan part.

My only thought on the spark problem theory causing uneven fuel burning in some cylinders is that the photo you showed of the plugs had 6 lean and 4&5 rich with 123 similar and almost normal. If you had a coil or ignition problem then it would affect all cylinders equally as it is upstream from the "distributor" (which evenly distributes the spark). This would affect all cylinders evenly. Since you have problems with 6 5&4 there is asymmetry and variance of the symptoms. This leads me to think if it is a spark problem it has to be distributor, or wires. However, it could even be an obstruction in the fuel rail on 6 and a common partial obstruction on 123 (but this is uncommon). EFI flow would be another area to confirm. Bad injectors are not uncommon. It could also be oil getting into 4&5 cylinders that blackens the plugs rather than fuel. Still a lot of possibilities.

1. Remove plugs and spray solvent into the cylinders.. fill em up. PB Blaster will work well. ATF and acetone 50/50 is even better. Run oil over the valves, remove and clean oiler bar with Throttle body cleaner (careful with gaskets). Drain gas (check for rust). Slosh some Acetone in tank if no rust (to clean out gum). Clean all electrical connections. 2. Let it set for a week. 3. Try turning at crank again with a long breaker bar or pipe on the crank nose socket ~2' to 3' 4. If it is still seized, tow the Z behind another truck/car (make sure brakes and clutch work) Go slow ~ 5/10mph and simply keep it in 5th/4th and let the clutch out when moving to grab the wheels. Then push clutch in. Do this a few times and it should work fine. 5. Try turning over at crank again. 6. If it turns drain oil and replace. Oil the cam again. 7. Turn over at starter with plugs out. Make sure all valves move smoothly under cam lobes. Make sure oil is pumped out of oil bar evenly on all lobes (if not, remove and clean oil bar). Note: It takes ~ 45sec of cranking to get oil up to the head. 8. Change distributor cap and rotor and plugs (NGK brand) and wires (NGK) 9. Check Rad fluid levels 10 . Check for spark and fuel flow 11. Start it up. 12. Replace all fluids, hoses, check brakes, clutch, EFI components, tires, etc. 13 Enjoy

The ignition unit and the coil "just make sparks". The distributor is a router and it directs the sparks from the coil to the appropriate cylinder. If you have problems with 5&6 then it makes sense that the components associated with these cylinders would be the culprit. The suspects would be distributor rotor and cap and plug wires. If you want to check your plug wires just idle the car in the dark and spray(mist) water on the wires...any problems will be seen as sparks to the valve cover and such (crappy Bosch wires did this within 5 months on my Rav4... DON'T BUY BOSCH WIRES

Argniest I love your attitude, perseverance, and very clear, concise and well formatted posts! Also your logic and careful approach to tackling problems is superb... keep it up! Stick with the NGK plugs and wires and you should have no problems. An easy way to check spark is simply to idle the car then pull one plug at a time. You can feel the spark with your hand on the boot and you can notice how far off the plug that you can hold the boot away before the spark won't jump. It should be the same for all plugs.

The ignition module is common to all plugs and injectors. Your problem is rich on 4&5 and lean on 6. This seems more like injectors. However it could even be something weird like obstructions in the fuel rail. Some more checks to do. Try getting 6 glasses (all same) then pull rail and have each injector sit in a glass. Crank and fill the glasses to see fuel flow across the 6. Watch out for spark. This is an old tip from Wayne Monteath of Ottawa.

BTW When you mentioned rust it made me think your #6 injector may be clogged. Did this on my 77. Easy and great upgrade: http://atlanticz.ca/zclub/techtips/distributor/index.html

http://atlanticz.ca/zclub/techtips/carbs/su/index.htm

To set the needle depth there are two methods I have used. 1. Hold a flat edge across the bottom of the piston and push the needle's shoulder against it then tighten the locking screw. 2. Screw Jet all the way up. Pull needle shoulder out slightly so that it is lower than piston's bottom. Ensure the screw that locks the piston is loose so that the needle can be pushed in and pulled out with gentle pressure. Place piston on carb (with no bell on) and let piston rest in place. The jet will then push the needle's shoulder to the correct depth. Carefully lift piston and tighten locking screw.

The needle's thick end/shoulder (where the needle taper stops and the flat cylindrical part of the needle starts) should be on the same plane as the bottom of the piston. (it should not be flush with the counter sunk groove that runs through the piston).

When you get your car sorted out, you should upgrade to a 280zx distributor. Also with rust in your tank you should install a filter before your fuel pump. When you feel brave, acid wash and sealing your tank is a fun thing to do with POR15 gas tank sealer.

Also check where plug wires connect to distributor cap. You can also measure FI flow: get 6 small glasses of same type, pull FI rail and place glasses under each injector. Crank the car to fill them up. After a certain amount of time you will see if you have even flow by the amount in the glasses... keep sparks away.

I think it was recommended to check the distributor cap and rotor. Easy to do and very inexpensive to replace. A bad coil would affect all sparks. A bad disturber cap would affect specific ones. FYI adjusting valves is a heck of a lot easier than all of the stuff you have done troubleshooting... I hope that gives you confidence

I would use just car wax as a sealer. Can be reapplied easily. There are new waxes that do not leave residue such as ice by turtlewax...yeah TW

Just noticed the end links I took off my S2000 are KYB Not sure if they are stock or the originals but they needed changing and the mileage is 75k

Great presentation of data! ~ 6ohms is normal for dropping resistors I can't recall the air regulator and fuel pump circuit test details. If the schematic shows this going through relay then the 61.3 ohms is probably carbon on the relay contacts or a corroded connector in the circuit somewhere. The injector test of 12.5 Volts is not measuring battery voltage. It is measuring the voltage at the ECU which will be applied to the injector harness. The resistance between the battery and and connectors and circuitry within the ECU upstream from your measuring point is causing the drop. btw a fully charged battery (measured with no load) is ~12.8V and fully depleted is ~ 12.0V (Measure after the battery is "settled" and has not just come from being charged by the alternator (during a ride or idling) or after it was just under load.... first thing in the morning is a good time)... btw battery V sould not be an issue with your problem... seems like bad connectors or bad injectors.

I like the rock guard in the quarter panel

Great presentation of data! ~ 6ohms is normal for dropping resistors I can't recall the air regulator and fuel pump circuit test details. If the schematic shows this going through relay then the 61.3 ohms is probably carbon on the relay contacts or a corroded connector in the circuit somewhere. The injector test of 12.5 Volts is not measuring battery voltage. It is measuring the voltage at the ECU which will be applied to the injector harness. The resistance between the battery and and connectors and circuitry within the ECU upstream from your measuring point is causing the drop. btw a fully charged battery (measured with no load) is ~12.8V and fully depleted is ~ 12.0V (Measure after the battery is "settled" and has not just come from being charged by the alternator (during a ride or idling) or after it was just under load.... first thing in the morning is a good time)... btw battery V sould not be an issue with your problem... seems like bad connectors or bad injectors.

I only ever tried KYB's on my 99 Rav4. They were much stiffer than stock.

i put a schematic drawing in your other post. There are two resistor blocks. Please note that injectors 1,2,3,4 are on one of the resistor blocks and 5&6 are on the other block.

Found another with "datsun" and some S13 200SX's (Nice 5 speed transmissions and 4.1 differentials... r180 and r200) http://newjersey.craigslist.org/pts/2334059167.html

yeah from your description it sounds like it is just the reaction disc that dropped.

http://southjersey.craigslist.org/pts/2278866238.html

Remove hood. Use one of the tilt accessories on the engine lift. Watch the transmission tunnel area as you lift and tilt and slide the assembly forward.