When setting ignition timing it says set with rpm at 600 but when setting curb idle it says to set curb idle at 600 in drive so on the ignition timing do you use 600 in neutral or 600 in drive. the veh i a 76 vette 350 auto

Here are the 3 engines listed for this year. IGNITION TIMING

2002 Nissan/Datsun Truck Frontier Pickup 2WD 2.4L SFI 4cyl

The Ignition Timing

18-22 DegreesBefore top dead center - When throttle positionsensor disconnected and using suitably programmedscan tool.When adjusting idle speed, set parking brake & chock drive wheels, curb idle speed (750-850 RPM)transmission in neutral.

IGNITION TIMING

2002 Nissan/Datsun Truck Frontier Pickup 2WD 3.3L SFI 6cyl

The Ignition Timing

8-12 DegreesBefore top dead center - throttle position sensorharness disconnected.When adjusting idle speed, set parking brake & chock drive wheels, curb idle speed (700-800 RPM)transmission in neutral.

IGNITION TIMING

2002 Nissan/Datsun Truck Frontier Pickup 2WD 3.3L SFI SC 6cyl

The Ignition Timing

8-12 DegreesBefore top dead center - throttle position sensorharness disconnected.When adjusting idle speed, set parking brake & chockdrive wheels, curb idle speed (700-800 RPM)transmission in neutral.

Check this video for idle speed adjustment. Backfiring can be caused by incorrect mixing in the carburettor or bad timing settings.


Check this link for backfire issues:

. What would cause Ford 390 to backfire through carb Yahoo Answers

Setting Curb Idle Speed of Carburetor Video Holley Carb DVD

Although your temperature gauge may show that it works, some models have a second temperature sensor for the engine management system.
That second sensor provides info which sets curb idle and timing advance. The "Cold start" feature is a part of this. The hic-cup is something of a bucking symptom as the engine controls toggle between hot and cold run settings repeatedly as water temperature is not stable.
In the past, I found several 1984 engines having defective thermostats which are tied into "Step-up" solenoids for the curb idle. What happens is idle speed is suppose to drop when the engine is hot.
When someone adjusts the curb idle while the engine is on the "cold setting", the setting(rpm) will be too low once the engine has heated up and the part drops to a hot setting.
So to clearly define your problem, you have 2 stemming from the same defects. The "in motion" problem is caused by timing changes based on temperature and the "idle" problem is caused by improper adjustment of the curb idle solenoid because of unstable operating temperature.
What you want to do is change your thermostat. This will give you a stable temperature. Then let the engine heat up and you should notice a "click" and the engine should idle down. It may stall. Then turn the idle rpm up until the engine will not stall.
The hic-cups should disappear once the operating temp is reached. If you still have problems then look for the water temperature sensors before replacing expensive parts.

Start with the idle needle screw first, the idle mixture screw. Seat it all the way in, first-don't overtighten and damage it, just seat it lightly, and back out two full turns. Run the engine and set the adjustment by ear to get your best lean idle: start turning the screw in (clockwise) 1/8 or 1/4 turn at a time till engine stumbles, dies, or runs rough. Keep the engine running, and turn screw out (counterclockwise) a little at a time till you hear the idle dropping. Now between those two settings is your best lean idle. Turn the screw in, a little at a time and wait for engine to respond, tiill you get the highest idle speed. Now set the other idle screw, curb idle, to the idle setting for your truck, probably about 700 rpm. You can move back and forth between the screws to get the best steady idle. Just don't over do it on the idle mixture screw.
Good luck.

my 98 chevy 1500 with 5.7 and 373 gears idles at 600 rpm, and at 55mph its running 1500 rpm on the dot

There is NO manual timing adjustment for the ignition. It is controlled by the knock sensor and the computer. If you need the timing marks for the timing belt, please respond and I will send it to you. If not, what kind kinds of problems are you experiencing?

3-13 Degrees
Application:
With manual transmission

Note :
Before top dead center, at specified curb idle speed.
Locate data link connector & connect jumper wire
between ground & engine test terminals.
After completing adjustment, remove jumper wire.
Curb idle speed (750 RPM) transmission in drive.

3-13 Degrees
Application:
With automatic transmission

Note :
Before top dead center, at specified curb idle speed.
Locate data link connector & connector jumper
wire between ground & engine test terminals.
After completing adjustment, remove jumper wire.
When adjusting idle speed, set parking
brake & chock drive wheels.
Curb idle speed (750 RPM) transmission in neutral

It might be the float but if you don't have any trouble getting the truck up to speed then it's likely fine. The trouble is more likely to be in the idle circuit. The curb idle should be 500 to 750 RPM depending on if it's standard or automatic ( higher for auto). If that's okay then you may have to play with the idle screws. Turn them both the same amount, 1/4 turn at a time. Turn them once and then rev the engine 2 or 3 times and let it idle down suddenly. You will have to re-adjust the curb idle to keep it at the right spot as well.
If the truck is an automatic, once you have it set up so it runs right then put it in gear and try again although that will probably only need the curb idle adjusted if it stalls. hope this helps.

6 Degrees Application: With manual transmission
Note: Before top dead center - When inspecting idle speed,
set parking brake & block drive wheels.
Curb idle speed (850 RPM).
Transmission in drive (parking brake engaged)

If your car does not have a ditstributor. You cannot adjust timing.
You need a timing light and point it on the timing marks on the crank pulley.

hello first check your idle with the car running foot on brake see were your rpm reading is if your below 500rpm check your label underhood for your curb idle setting second see if theres a adjustment screw you can increase were your gas cable lever rest against your set screw underhood if you feel confident enough remove your iac motor idle air control valve if the bore were the end of the pintle extracts out to close has varnish builup our carbon it will stick creating vacuum leak type senario causing stalling rough idle sometimes even no start conditions good luck