Discussion Starter · #1 ·
So it all started last weekend when I noticed that driving on the thruway I was getting up to 9 psi. Well I thought it was odd but it didn't seem like a "bad" thing at that point. Then no noticeable problems til last night. I was driving to the track on a country road and the car starts bucking and I couldn't rev over 4K. Under hard acceleraton very bad. When accelerating slower, boost would stay around 5-6 psi and would barely do it. It feels like hitting a rev limiter or maybe fuel cut? Later at the track and on the way home when coming to a stop, the engine would stall. It restarted without a problem. Driving today, 1st gear is OK but when accelerating somewhat hard, then shifting, boost would go up to 9 psi (maybe 10) and the car would start bucking pretty bad and wouldn't accelerate any more until letting off the gas and then resuming at maybe half throttle. But some times it does it when just cruising along at 20-30 psi of vacuum. So it seems like it might be misfiring. I read the "bucking" post in the engine section, could some of this apply to the 7M? The fuel pump is the original with about 114K miles on it. Probably somewhat tired at this point especially with the increased demands the 7M is putting on it. The filter is the one that was on the old 5M. It's a Toyota filter with about 5K on it. I'm going to order a new one tomorrow, I was planning on replacing it anyway. The engine (and injectors) had about 85K on them before the rebuild. And I've driven the car maybe 500 miles since. The wires are new NGKs. The plugs are new Denso Iridiums. I've run only 93 or 94 octane gas since the swap. I couldn't find any loose or disconnected vacuum lines, intake pipes, etc. I'll try and find a different ignitor, TPS, ECU to try. Also my EGTs don't go up when the bucking occurs which made me think it might be a misfire problem and not a fuel delivery problem. I have no boost controller that could be malfunctioning, just the stock wastegate. I don't have any cats that could be clogged, just 2.5" pipe and a straight through muffler. I'd appreciate any suggestions.