Won't rev past 2k RPM
02-08-18, 02:50 PM
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Won't rev past 2k RPM
Hey guys, I'm trying to help a friend with their '01 IS300 (automatic, CA-spec).
So the engine won't rev past 2000 RPM. He was driving on the freeway and it bucked and died, then jjwouldn't rev past 2000 RPM. Before the incident, he had been driving around for months with a P0440, which he thinks is probably a broken overfill check valve. After the incident, it had a P0715. A dealer diagnosed it as needing a new transmission, but the transmission seems fine. They also said they would need to replace the entire EVAP system for the P0440, so the whole thing reeks of dealer BS.
When it gets to 2000 RPM and starts bogging, my scanner shows that the EFI goes from closed loop to open loop. If you give it just enough throttle to stay below 2k (say, at 1200-1500), it starts hunting. This is making me think that it has a clogged cat.
I tested the fuel pressure, and it's at a steady 49 PSI, holds that for five minutes after shutoff. The TPS reads from 14.9 (at idle) to 79.2 (foot through the firewall), which seems normal compared to what I've seen on other Toyotas. The MAF is a used unit out of a 2004 Sienna, and reads within range (also tests out as per the FSM). The part number matches the compatibility list.
What do you guys think?
So the engine won't rev past 2000 RPM. He was driving on the freeway and it bucked and died, then jjwouldn't rev past 2000 RPM. Before the incident, he had been driving around for months with a P0440, which he thinks is probably a broken overfill check valve. After the incident, it had a P0715. A dealer diagnosed it as needing a new transmission, but the transmission seems fine. They also said they would need to replace the entire EVAP system for the P0440, so the whole thing reeks of dealer BS.
When it gets to 2000 RPM and starts bogging, my scanner shows that the EFI goes from closed loop to open loop. If you give it just enough throttle to stay below 2k (say, at 1200-1500), it starts hunting. This is making me think that it has a clogged cat.
I tested the fuel pressure, and it's at a steady 49 PSI, holds that for five minutes after shutoff. The TPS reads from 14.9 (at idle) to 79.2 (foot through the firewall), which seems normal compared to what I've seen on other Toyotas. The MAF is a used unit out of a 2004 Sienna, and reads within range (also tests out as per the FSM). The part number matches the compatibility list.
What do you guys think?
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