loosing power!!!

[mys13240]

hey. i have a recently purchaced a '90 240 with aprox. 103K on it. Some times when i get on it in secound and get towards the redline, say around 5k, it cuts out until i get to 3k rpm. it does it also when i get to 4100 rpms in 5th. and if i dowshift to 4th and go almost to redline, like around 5.5-6k revs. if you have any info on this subject, i would appreciate it. also , the first time o got it on the highway, i was cruising at about 70-75 and it lost power breifly a few times in 5th. if this helps in any way, my speedo goes in and out.

[Nismo_Freak]

Speed sending unit... it's causing your ECU to fuel cut like it's hitting speed cut.

[mys13240]

IS that the same thing as the speed sensor?

[s13sr20chris]

yup

[Nismo_Freak]

Yes.

[mys13240]

thanx . i guess ill try to get one then.

[s13sr20chris]

also check the speedo head. they mess up and cause this problem all the time.

[Nismo_Freak]

Speedo can't cause the engine to run poorly... it has no bearing on the ECU's operation.

The problem is before the ECU's intervention, which is only the speed sensor.

[s13sr20chris]

ill check on that exact model, but on most nissan models the speedo signal goes to the speedo head first then to the ecm. thats why you can set a speedometer code without ever loosing your speedometer reading. i will double check and make sure that its like this on a '90 240.