N W Fuel Injection Service 1983 Limited

I took my truck to them for a shake at idle. They diagnosed it as injectors out of balance, and suggested replacing. I asked what could prevent future damage, a second fuel filter was recommended After my truck stalled repeatedly as it wouldn’t hold prime. I limped it back to them to fix temporarily. Was a result of loose hose clamps allowing air sucked in on the installed second filter At the end the original idling problem that it was brought to them for was not fixed by the new injectors!