Running On 5 Cylinders ....Help

[hbar]

I was told I was running on 5 cylinders .......
Changed plugs and cap/rotor and still missing at idle.....
If I don't see any fouled plugs what do I look for next ??
Any advise or suggestions ??

HB
93 Pathfinder XE 6 4WD

[Hawaii 5-0]

Is it missing only at idle, or even under throttle?

The reason I ask is my '98 is prone to cloged/dirty injectors. I have had problems 2X already with an injector being so dirty that the affected cylinder was missing consistently at idle and under throttle. The engine was running really rough, even got SES (service engine soon) indicator light on the dash.

First time, Nissan dealer flushed the injector under warranty. Told me they would charge me if it happened again. Well it happened again not too long afterward. I gotta admit though that I use the cheapest gas around, though I do use premium. Anyway, I went out and bought Chevron Techron fuel injector cleaner and ran about 1/2 a tank of treated gas through before it got cleaned up enough to take care of the problem. I was running the car with the overdrive off (automatic tranny) to keep the rpm's up to run more treated fuel through the injectors. If you have a manual tranny, just keep the gears low and the rpms higher than you normally would when you drive around.

Now I don't wait for the injectors to clog up, I run 3/4 tank (cleaner only treats up to 16 gallons of fuel) of treated fuel every other month to keep the injectors clean. So far, I haven't had any more problems.

Hope this helps, and good luck.

[hbar]

Thanks for your replly......
Hard to tell if it's missing under throttle....... idle is relativly smooth and no "check engine" warnings......
I do use Techron from time to time as well as the German LubroMollly LECTRON and VENTIL ZUBER ......
Will try Techron again and also plan to replace plug wires.......

Any other suggestions would be greatly appreciated.....


hBar

[88pathoffroad]

Originally Posted by Hawaii 5-0

I gotta admit though that I use the cheapest gas around, though I do use premium.

Using premium fuel when it's not called for is a complete waste of money. It's formulated to burn SLOWER than lower octane gasoline and therefore reduce detonation on higher compression or forced induction engines. Lower octane gas does the same job the way the vehicle manufacturer meant it to, costs less and contains the exact same amount of particulates and additives as more expensive fuel. There probably won't be any performance difference whether you use super unleaded or regular, but the more expensive gas is a complete waste.

[Hawaii 5-0]

Originally Posted by 88pathoffroad

Using premium fuel when it's not called for is a complete waste of money. It's formulated to burn SLOWER than lower octane gasoline and therefore reduce detonation on higher compression or forced induction engines...

Thanks, but yeah I know this... I switched to premium because my valves rattle when going up hills when I use regular unleaded 87 octane gas. It runs fine on premium 92 octane gas.

[hbar]

Replaced plug wires with new Nissan set .......... still missing at idle.....

hBar

Originally Posted by Hawaii 5-0

Thanks, but yeah I know this... I switched to premium because my valves rattle when going up hills when I use regular unleaded 87 octane gas. It runs fine on premium 92 octane gas.