My silver zzw30 is misfiring on cyl #4 and I cant seem to get it figured out. Its got a haas turbo setup that has been running reliably for years. The problem began with con rod bearings getting a little rattly, I swapped in a new toyota factory shortblock and it ran great. Then one day it developed a misfire, I did a wiggle test on the side of the road, determined it was cyl #4 injector harness (pigtail adapter harness loose terminal). Was far from home and had to drive/wiggle/drive wiggle and so on as it would loosen up as I drove. I deleted the pigtail and soldered on the proper connector, problem solved, ran good for 1/2 hr then misfire came back. Now nothing i do will fix it. Im at the end of my rope. Did the wiring damage the injector? The cylinder (and all others comp tests at 190 psi so I dont think it leaned out and hurt the motor). I swapped coils to see if it followed, nope, injector swap seems like next thing but its a hassle cause mid engined. (Not the end of the world, just a fussy job). Any ideas? I'm at a point where I'd pay to have someone look at it but it's such a modded car, I dont know where to bring it. Help would be a godsend.
ShawnG
UltimaDork
8/5/20 9:49 p.m.
It's coil-on-plug, did you check to see if it's burnt a hole through the tower on the coil and is arcing through the spark plug tube?
In reply to ShawnG :
I swapped em around to see if it followed. Did not follow.
It's driving me crazy, this was my dd till this happened, had to buy a new dd cause I've been messing with it so long. It's totally freshened up in the last 2 years, new factory engine, new turbo, tew trans with lsd and six speeds. Now its dead in my garage for 6 months. Aaarrrrggghhh!
Codes are for misfire cyl4 and rich bank 2
Six months to change out an injector on a mid-engine car?
We need an intervention. 
One WAG. While the cylinder wasn't firing, it carboned up the injector. when you got the wiring repaired, it was too late. I vote for bad injector. There are shops that clean and service injectors.
You swapped plugs, but how hard is it to swap injectors with another position?
Could also ohm them out and do other basic tests with it in position.
Passes a smoke test of intake.
Who do we like to send the injectors to get em tested and refurbished if needed? Im happy to just do it as something to try.
I've seen guys successfully clean injectors by soaking them in BG 44K. Maybe worth a try if the injector(s) looks dirty.
Mr_Asa said:
You swapped plugs, but how hard is it to swap injectors with another position?
Could also ohm them out and do other basic tests with it in position.
I can do it, at this point it's worth the pain in the ass. Anyone know where to get specs for resistance? I dont know the manufacturer (or even the cc) they came with the white car.
can you get a stethoscope of any sort (real or improvised) on the injector to verify that it's actually doing anything at all?
Vigo (Forum Supporter) said:
can you get a stethoscope of any sort (real or improvised) on the injector to verify that it's actually doing anything at all?
Good call. Ive got a kick ass electronic mechanics stethoscope, ill try that too.
Just swap injector with another cylinder and sere if it follows.
Can you add fuel to the intake (an unlit propane torch is great for this) and get the engine to smooth out? Simple way to tell if it's fuel or not. Propane would allow you to feed it in pre turbo since it will not settle out before getting to the engine.
If it IS fuel, I do not quite understand the mechanism, but I have seen Toyotas eat the injector driver in the computer after a bad connection at the injector. A noid light, or an extra injector you can plug in and feel rattle in your hand (or not) will let you know which direction to go in.
I'm all over fuel stuff tonight. Strange that it started with that bad connection. Hope its not the injector driver (ecu?) or something.
I'm pretty tired, was instructing in a 12c and 911r all day (humble brag). Im exhausted.
