2007 25 hp mercury 4 stroke efi f25elpt s/n or185161

by kevin

poor wot rpm,
I am working on this engine and it is giving me fits. Under load this engine will only reach about 2500 rpm at wot. With the fast idle I can reach full wot rpm. I have replaced the low pressure pump as the engine would surge at full throttle. I have test fuel pressure at the fuel rail and have 43 psi running, the injectors are reading 12.6 ohms, the iac tests at 29.4 ohms. I have check for spark and have good spark cranking and running from all 3 coils. The tps test is closed and open reading as follows-blue to black-closed:5100 ohms, open:5100 ohms, yellow to black-closed:790 ohms, open:3400 ohms, yellow to blue-closed:4700 ohms, open:2100 ohms. This is the only sensor that I have found that seems to be out of specs and was curious as to if anyone has any insight on if this is or could be the reason for my poor wot rpm? I do not have the diagnostic software for this particular engine as even though it is badged mercury in my research i believe this is actually a tohatsu powerhead and requires special software that I currently do not have. any and all help would greatly be appreciated

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