Hi all,
I have a 2011 ZZR1400 which is currently running badly down on power.
Initially I was losing power under hard acceleration in the higher rev range, and noticed a high pitched whine from the fuel tank after the bike had been running for some time. I pulled and checked the fuel pump and found the filter was clogged. I replaced the lower filter element, but found that I was still having issues with both the noise and the lower power, so replaced the pump and the pressure valve at the same time. After doing this I tested the fuel pump flow rate and pressure and found I was getting the minimum 67ml over 3sec, and 43PSI. However, I am still down on power, and the whine was still present. I replaced the fuel pump AGAIN and found that the whine has now gone, but I am still down on power.
If I do a slow roll on in first gear I'm able to get up to about 10k rpm, but then in second gear it starts to struggle a bit around 8k rpm. If I go WOT from the mid rpm range (6-7k) in either first or second, the bike just bogs down and has no power whatsoever.
Two days ago I was riding it and it was a far hotter day than previously, and I was finding that even part throttle from the mid rev range was causing the bike to bog down - this was happening in all gears.
The bike is mainly stock, it has got aftermarket slipons and a K&N air filter in it, and I was running a PCV map.
So far I have replaced the fuel pump, disconnected the PCV, checked the spark plugs, run through a bottle of injector cleaner checked the air filter and the ram air tubes.
Last night I tested the atmospheric pressure sensor and the air inlet pressure sensor with the bike at idle, both read in spec according to the service manual, and both read the exact same value. I tested the air intake temp sensor the same way and was getting bad readings, so removed the sensor and tested it independently. The sensor tested fine, so I have checked the wiring between the ECU and the sensor plug - which is also OK. I'm guessing I didn't get a good connection when back probing the ECU pin for the temp sensor. I tested the TPS which returned good readings.
I'm starting to run out of ideas here, so would appreciate any thoughts on what to test next. I am going to re-test the fuel pump flow rate and pressure, but I feel like at this stage my problems must be somewhere else, especially given the way the bike behaves when the air temperature is higher.
Cheers
Chris