BobbyB13

Hi,

I'm presently trouble-shooting very random misfire from my Evo 9 SE: randomly throwing P301, P302, P0304. When the car is misfiring it is barely driveable, (yes - that was me on the side of the NJTPK NB truck lane last night), but when it isn't, it drives perfect.

Among the many other tests I'm running, (thanks to the great info from this community), I tested the injector resistor box.

Per the FSM I should be reading 5.8-6.2 k-Ohm at room temperature for all the resistor box pin-outs, but I measured twice last night after the car sat for 3+ hours and got two different readings, but the only consistent readings were 7.8-8.0 k-Ohm.

When I first measured 1-3 I briefly got 6.5-6.8, but I could not replicate that reading. My thought is that after taking all the readings that the resistor box reached a steady-state condition around 7.8 k-Ohms.

Does anyone know what the "real world" threshold is for this box? i.e. Exceeding the OE-spec of 5.8-6.2 k-Ohm to could start to yield sporadic problems?

Thanks in advance for the help, everyone.

CAR: 182k highway miles daily-driven 365 in Rockland, NY, and N-NJ (yes - winters included, 23 psi street tune w/ wide-band, cone intake on stock MAF, turbo-back exhaust incl. high-flow cat, always garaged, only driven hard at toll booths a few times a week.

RECENT WORK: Literally happened 30 miles after full blown timing belt change-out and stock top end rebuild. No leaks, no smoke, oil looks clean on dip stick, etc. and the mechanic who did that work is checking it all out now.

P.S. Please let's not turn this into the millionth misfire thread, (but if you have to)... I'm cleaning and re-sealing injectors tonight (never done before), coil packs and wires are arriving Mon/Tues (also never done), the gap on the stock plugs was way too tight around .012-.015 so I opened to .024-.026 (brand new but way out of spec), will check TPS voltage tonight, ... Test drive last night went perfect, but this is my daily driver so I want to check everything.

BobbyB13

Update: Changed out coil packs and wires, installed new injector seals, re-gapped spark plugs, and so far so good.

Any input on these stock resistor boxes though? When have people running stock injectors had to replace these due to wear and tear? Thanks