Plugs fouling out on cylinders 3 & 4
 

Ok, I am going to try to make this as thorough as possible. My dilemma is that the plugs in cylinders 3 & 4 keep fouling out. I have switched around the injectors and it is still fouling out the same plugs. I have done a compression test and each cylinder is 145-160. I have tested the fuel pressure and it is coming out at 41 psi. I have also changed out the fuel pump, fuel filter and fuel pump relay. I am running MS3 on the car as well as being supercharged with a Rotrex kit from Kraftwerks. I am also running RX8 yellow injectors. This has been driving me nuts for the past couple of months. It seems no matter what I think it is, it's not solving the problem. I just figured I would come here to see if anyone else can give me suggestions as to what it might be. Perhaps there is something I am overlooking. So any help would be greatly appreciated. Forgot to mention that it is a 2002.

Thank you!

P.S. I am sure that there are bits and pieces that I am forgetting, so feel free to ask me more questions. I want to get this car back to running in tip top shape.

You could probe the voltage at each injector to see if they all read the same. If you've got a weaker voltage on 1 and 2, it'll cause the AFR to average higher, so you'll put in more fuel to compensate. This would on average put more fuel into injectors 3/4.

Kneejerk siag without knowing more about your setup is your B-channel injector driver is meh if you're running batch injection.

The set up I have is a Kraftwerks Rotrex supercharger, Skunk2 intake manifold and throttle body, RX8 yellow injectors, Megasquirt 3 and Fab9 COP kit. I am running sequential injection.

Self built? PNP? MS3 or MS3x? Tune?

It was an MS3 built by Ohio ECU Solutions and it has some tuning done on it. Tadd was down the other week and we did some tweaking on it, but it's still fouling out the plugs on 3/4.

Never heard of 'em. By tune I mean "Post your tune." - your msq file. MS 3.0/3.57 board only has 2 injector outputs - more can be added, or if it's a different board like a pro / diypnp - it somewhat of an unfortunate naming scheme but details are important here. MS3x has more built in.

Creeping on their FB - I see they've used a DIYPNP (which only has 2 injector outputs) and a 3.0 board (which only has 2 injector outputs).

Post your tune, lets see if it is actually sequential.