NOTE: I posted this in the "4th gen T4Rs" forum initially. Re-posting here. Sorry about that!

Injector question: Is it possible to test the resistance of the fuel injectors on the driver side (2, 4, 6) WITHOUT removing the supercharger (or plenum for non-SC vehicles)?

BACKGROUND:
On Friday last week I picked up my 2000 SR5 manual from the tire shop. Got home, realized I forgot something, and jumped back in the truck, but as soon as I started up and began to roll I could tell there was something wrong. Engine felt rough and with a manual you can really tell when there's a power loss.

A few minutes later, check engine light came on. P0300 and P0302. Interestingly enough, once I got on the gas to merge into traffic I felt the roughness disappear and had full power. Truck ran fine after that for about 10 miles and 2 trips.

Then yesterday, ran to the store and truck ran fine. Parked for about 20 minutes. When I restarted the truck, engine was back to rough idle and low power, but this time, no codes. Drove about 6 miles home, rough all the way, no codes, no check engine.

Last night I pulled the spark plug from the #2 cylinder and everything looked good. These Denso Iridium IK22 plugs have about 20,000 miles on them, and I do have a supercharger so it can be hard on plugs.

Ordered new plugs anyway, and am going to run Lucas lube and injector cleaner tonight.

Drove a couple nights ago, and same experience: Runs great when cold started. Any re-start with a warm/hot engine is triggering the rough engine/low-power but no more codes.

When I posted in the wrong forum earlier, Buckaroo gave some good guidance and a link to a thread that eventually led the poster to a bad injector with similar symptoms.

I have 3 new coil packs in hand and am going to swap in a new one for the "1-2" coil pack today... assuming that the P0302 error was pointing to the right cylinder. But I'm pretty confident I'm looking at a bad injector.

I also have new plugs, but I'm pretty sure the plug was fine. The wires aren't very old, but if I end up doing the injector(s) I'll probably just swap wires and plugs as well.

Before swapping in a new coilpack, swap the suspect coil to a different location and see if the issue follows. 20k is a bit early for spark plugs (30k interval for the SC, right?), but not a bad idea and not too expensive.

Moving the suspect coil allows you to PROVE that was the issue or not, instead of guessing with new parts. Make sure you get genuine Denso or OEM coils if you are replacing.

You can test injector resistance partially from the ECU plug, but that also introduces possible wiring/connector issues between the injector itself and the ECU connector. You still have to remove the glove compartment, but that is easier than the manifold/SC.

-Charlie