TuJay
Proven Member
- 94
- 1
- Aug 16, 2016
-
Wadsworth,
Ohio
And I don’t think when they did the fuel system they even bothered with tuning it, that’s why it’s rich. I don’t know how to tune and ECMLink won’t connectWith a Walbro 255 you'll definitely be running rich without some sort of aftermarket fuel pressure regulator. Since you have an AFPR, you're likely okay as long as the previous owner set base fuel pressure correctly. With DSMLink, and an AFPR, the car shouldn't be running rich unless (off the top of my head) it is either tuned incorrectly, the wideband 02 sensor is calibrated incorrectly, or you have some sort of post-turbo intake leak.
A fouled plug won't spark, or will spark weakly, so it could be causing your problems yes. The 4G63T is picky about which plugs are used. NGK was OEM for our cars, so most people run either the NGK BPR6ES if they are running stock boost, or BPR7ES if they have a highly modified vehicle (30+lbs of boost iirc). Plug gaps are also very important on this engine: .28-.32; most run either .30 or .28. The plugs are 13/16 (21mm I think) wrench size, yes. For plug wires, it's also important to run wires with low resistance; many run NGK ME-77.
All that said, my gut feeling is that, if you're missing a couple of cylinders, your plugs are wires are fine and the issue is somewhere further upstream in the spark system (coils, ignition transistor, or the signal from the ECU/Cam Sensor to fire). Still, I'd check the plugs for fouling/check their gap, and ensure you have spark on all four before you throw money at the problem. If you have no spark, knowing whether it's missing on 1&4 or 2&3 will narrow down what you need to look at to track down the source of the problem.
Since it's hard to diagnose via video, if it turns out you have spark and fuel on all four and you're not missing cylinders, I'd guess a big intake leak.