Nissan Repair: Nissan Frontier Missing, nissan frontier, advance auto parts

Question
QUESTION: I have a 1999 Nissan Frontier 4x4 with a v-6 engine automatic transmission.  I recently purchased a full tank of gas and drove about 1 mile and the truck started missing.  I probably drove another 50 miles and the miss got more severe until finally the truck would hardly run.  When I would spot at a light i would have to kick it into neutral and hold the accelerator down a little to keep it running.  When the light would change I would place the transmission in gear and the truck would miss fire so bad I could hardly get through the light and it would take a long time to get up enough speed to stay out of everyone's way.  I finally made it to Advance Auto Parts and they checked with a code reader and it said Knock Sensor.  I made it to a garage and they replaced the fuel filter and it ran much better, they said the fuel filter was blocked up badly.  I used some chemical to take water out of fuel just in case it was fuel with water problem.  Doesn't seem to make much difference.  While it is running much better after the filter change it is still missing.  However, it does not miss as bad when the engine is cold as it does after it warms up. I have had a lot of suggestions from friends from fuel pump to spark plugs.  I should tell you that the spark plugs and plug wires are only about 3 months old.  I feel like I must have gotten bad fuel but I don't know what to do and I don't want to start changing parts.  The garage said if the fuel filter didn't help they wanted to tune it up and if that didn't help they would try something else.  It is said but it appears the mechanic is just a change a part and if that doesn't work change another.  I could win up with a lot of money in repairs I don't need.  Please any advise would be appreciated.

ANSWER: Billy,

If you are sure it is fuel related.  Have the tank drained and put in new gas and a fuel additive.  Also, replace the fuel filter again and go from there.  If that does not do the trick you are going to have to check into the tune up you had done and make sure the plugs are good and that the rest of the parts are not causing problems.

---------- FOLLOW-UP ----------

QUESTION: I removed the tank and drained it, replace the fuel with premium fuel and added a can of heat to the tank.  I also replaced the fuel filter again.  I also installed new sparkplugs and the truck ran better for about 2 miles and started missing again.  I should have told you that when I removed the tank and drained it I filled a clear glass gallon container from the tank and after letting it sit for a little while there was about a 1/2 to 3/4 inch of water in the bottom of the container.  I still think it is a water problem, but could you tell me how many time I should expect to change the filter before it is all gone from the system and lines and the truck gets back to running ok.  It misses at idle and will while it may run smooth for a little way it will start missign and jerking bad only to smooth out again for a short distance..

Answer
Billy,

I would inform the gas station of the issue and see if they are willing to pony up the bucks for your repairs.  I am sure there are more people than you that had this problem.

Back to the truck...  I bet your injectors are plugged up and you are probably going to have to remove them and blow them out with carburetor cleaner and reinstall them.  The way later model Nissan fuel injection works is that it is not a feedback system.  That is, the excess fuel is dumped at the pump back into the tank instead of the old way of circulating fuel from the tank to the injectors and them back to the tank.  So, any water that made it up to the fuel rail is still lingering.  I would remove the rail, with the injectors.  Spray carburetor cleaner in each injector and drain it out.  Do the same with the fuel rail.  Install yet another fuel filter and fill up with gas and fuel treatment and you should be done with the problem.