Timing

http://www.fuelinjector.citymaker.com/Vortec_spider_fuel_injection_conversion.html

i need to know when it is recommended to change timing belts on a 2000 nissan frontier 4 cylinder. at what mileage?

about 100,000 miles

The 4-cyl engine uses a timing chain, not a belt. There is generally not a change interval for timing chains, but they should be inspected for signs of excessive stretching from time to time. There are signs of excessively stretched chains requiring replacement, like timing drifts and rattling sounds.

can a battery cause a p0300 misfire code?

At 14 years old it’s also possible that timing chain stretch combined with sprocket and chain guide wear have combined to throw the valve timing off.

It’s also possible that you have a fried valve or two.

Have you put a vacuum gauge on this puppy?

Oh, and the “when I turn one way” problem could simply be that the ol’ power steering pump is adding load to the crank and exacerbating the problem. I wouldn’t read too much into that until you fix the misfiring.

I had a '99 S-10 4.3 V6 and I am sure it did not have multiport injedtion.

It does, you just can’t see it unless you take the upper plenum off. Click tester’s link. That’s what you will find under the upper (plastic) plenum.

how can i test the the injectors and what do i look for when i take the upper plenum off how can i tell if it is bad? what tools do i need to do this job?

ellyellis you do have muti port injection the injectors are hidden under the upper plenum.

how can i test the the injectors and what do i look for when i take the upper plenum off how can i tell if it is bad? what tools do i need to do this job?

Usually, the “legs” of the spider setup will deteriorate and begin leaking. The poppets are held into their ports by a simple snap clip. Just squeeze the tabs and they come out. Inspect the tubes leading from the unit to the poppets for wear, cracks, and leaks. I’m sure there are other ways this unit can go bad, but leaks in the tubes is definitely the most common mode of failure.

I thought you said in another post that you had already verified that this was not the problem???

DTC for which Freeze Frame was Stored P0300
Fuel System 1 Status Open Loop
Fuel System 2 Status Open Loop
Calculated LOAD Value 3.53 %
Engine Coolant Temp 91.40 °F
Short Term Fuel Trim - Bank 1 0.00 %
Long Term Fuel Trim - Bank 1 0.00 %
Short Term Fuel Trim - Bank 2 0.00 %
Long Term Fuel Trim - Bank 2 0.00 %
Intake Manifold Absolute Pressure 10.66 inHg
Engine RPM 768.00 rpm
Vehicle Speed Sensor 0.00 mph
Air Flow Rate Mass Air Flow Sensor 0.94 lb/min
Absolute Throttle Position 0.00 %