Idle drops

[slowspeed]

I'm having a werid idle probem. Just finish the wiring on rb26 swap into 240z . The motor starts up fine went for a test drive,drove fine but few prbolems on the way. but the main conern is the idle drops ,like it wants to die. At idle, it idles good but when you rev it high at idle it wants to die then the idle comes back up. I have aeromotive fuel pump,filter and fpr. I check the voltage at idle its good 12v and when i rev it it drops to 5 to 6 volts. Any ideas what can cause the drop idle when rev up high.????/:fmad:

[Rumnhammer]

Are you measuring the voltage at the fuel pump, and it is 5 volts? you may need to run a dedicated 10gauge wire for the fuel pump if that is the case.

I'll be posting this after I get it done.

Chris Rummel

[slowspeed]

Chris , yes i do have a 10 gauge wire running to the fuel pump. At idle it idles fine ,but when you rev it up, like snap the throttle, the idle drops really low like it wants to die.

[z_cars_rule]

i am guessing you mean when you rev it up then let off, as the revs come down, they dive below idle?

 

my car does this (RB20DET), reason mine does it is because it runs off the TPS and a MAP sensor, the vacum in the manifold is different when you i let off, and the ECU sets fuel and spark according to that, but once it gets down to a certain point it will come back up.

 

if yours is doing something different, then this means nothing. or if you are still using AFMs it should not do this for my reason.

[slowspeed]

Z cars rule ..Thats what i meant when you rev it up then let off the revs comes down below idle. I have rb26 swap,I'm using AFM I don't think the rb26 motor uses a map senor,But i could be worng. Any reason why it does that??? How did you hook up your vacumm line to your FPR??

[z_cars_rule]

FPR is exactly as the motor came from the factory. i have an aftermarket ecu, that is why i run my motor on a MAP sensor.

 

I would not be worried about it at all, unless it is dropping down that far that is almost stalls.