Thanks Scotty for making me one of your Moderators. I'll chime in whenever I have the time. As for my question, I have a 98 Acura RL with a 3.5L V6, the same motor that's also in the Honda Odyssey Vans. Anyways, the motor is not the original motor, it was a junkyard one that came from Japan the same week as the Fukushima disaster in 2011 (of all places). The previous owner claims it was put in 2011, but it burned oil. 3 months ago he gave the car to me. Recently, I was driving it down to his house on the highway, going 75 mph, and when I got off, and stopped at a light, the idle dropped down to around 500 rpm's. When the light turned green, I stepped on the gas, and it hardly moved. The fastest I could go was maybe 10 mph. Thinking the tranny died on me, I shifted it into neutral to test if the motor was broken or the tranny was broken. I floored it, and the motor rpm's barely went up to 900 rpm's. So now I'm thinking the ECM went into "Limp Mode", and the car was barely drivable. Long story short, I got it towed home and changed the fuel filter (old one rattled), spark plugs (all old ones fouled), and valve cover gaskets (they leaked oil into the spark plug wells). After I checked the repair manuals, and replaced the Igniter (Ignition Control Module), the car Cranks, but No Start. I towed it to a mechanic, who checked the fuel system, starting system, ignition system, battery and charging system, crankshaft/camshaft position sensor, Igniter (Ignition Control Module or ICM), Ignition Coils for spark, fuel pressure test, cylinder pressure test, all fuses, everything you or I or any mechanic would check, and his conclusion was I have everything - fuel, spark, air intake - everything needed to start the car, but for some odd reason, the car won't start. It Cranks, but No Start. It threw trouble codes: P0300, P0401, P0420, P1201-P1206. Now he's thinking the ECM is faulty, and is suggesting I tow it to the dealer for repair. Seriously, it can't be THIS difficult to get this beast a going. Any thoughts?
Oh, and by the way, the motor is a JDM motor (Japanese Domestic Market) installed in 2011. JDM motors don't use or have the same emission controls we have here in the states. Nor do they have Immobilizers in their cars. My car has a few "absent" emission sensors, BUT it does have an Immobilizer. Based on that, we think the previous owner used the JDM wiring harness, but used the American ecm.
OK, here an update: took the beast to the dealer. They checked EVERYTHING. They even claimed over a dozen mechanics have look at the car and every one of them still can't figure out what's wrong with it. The chief mechanic says it has fuel, spark, all sensors checked OK, compression is good, it should start. BUT, it don't start. His conclusion: bad ecm. So that's where I at. Looking for a reputable company that repairs broken ecm's. I think I found one, but they haven't responded to me yet. I'll let ya know.
try a new main relay and pray it's just that. if not, often it is the ecm that's gone bad. But also find a pro with a dealer level scan tool to see if the anti theft system has activated, I've seen that too. Good luck.