code 21 + fuel pump issues

[entrapm3nt]

I bought this car recently. The guy said he put a new fuel pump in it but i can not hear it. fuse is good relay clicks. fusible link appears not burnt. cannot hear the fuel pump. Can i just pull it out and see if it looks new? Would the fuel pump be the cause of the code 21 from the ecu? "ignition signal circuit " is code 21. Is this the cause of my problem or do i have more trouble ahead of me? also tested the injectors #3 is bad #6 is a little high on the ohms. It should still start with bad injectors tho.. Should i just order a new pump? btw the car is a 91 NA 5spd 2+2 and yes. I have the new version of the PTU so it shouldn't be the problem.

[t.mcginley.jr]

I bought this car recently. The guy said he put a new fuel pump in it but i can not hear it. fuse is good relay clicks. fusible link appears not burnt. cannot hear the fuel pump. Can i just pull it out and see if it looks new? Would the fuel pump be the cause of the code 21 from the ecu? "ignition signal circuit " is code 21. Is this the cause of my problem or do i have more trouble ahead of me? also tested the injectors #3 is bad #6 is a little high on the ohms. It should still start with bad injectors tho.. Should i just order a new pump? btw the car is a 91 NA 5spd 2+2 and yes. I have the new version of the PTU so it shouldn't be the problem.

A better way to tell if the pump is good is to apply 12v directly to see if it runs.

[entrapm3nt]

I bought this car recently. The guy said he put a new fuel pump in it but i can not hear it. fuse is good relay clicks. fusible link appears not burnt. cannot hear the fuel pump. Can i just pull it out and see if it looks new? Would the fuel pump be the cause of the code 21 from the ecu? "ignition signal circuit " is code 21. Is this the cause of my problem or do i have more trouble ahead of me? also tested the injectors #3 is bad #6 is a little high on the ohms. It should still start with bad injectors tho.. Should i just order a new pump? btw the car is a 91 NA 5spd 2+2 and yes. I have the new version of the PTU so it shouldn't be the problem.

A better way to tell if the pump is good is to apply 12v directly to see if it runs.

That would still require me to pull the pump correct? Is it possible that maybe my Fuel Pump Control Unit is bad? I tried to pull up the panel but it feels like its gonna break. i cant see if its burnt or not without removing the full panel. also, is the fuel pump relay under a big panel near the fuze box under the driver side steering wheel? I dont think i hear it click and also having the same problem i dont wanna break these fragile plastic interior pieces.

[NolimitZ32]

You can put 12v to the pump without pulling it, just pull the carpeted cover of and you have access to the contacts.

[nissanfreak12]

You will not always hear the fuel pump in a vehicle. Don't go by just that. Code 21 is ignition, has nothing to do with the fuel pump. What you need to make sure if all the grounds are connected at the back side of the plenum, if they are not connected, this has been known to fry the PTU, whether its old or new. I would also look at the connections make sure there is no green crud and they are connected nice and tight no crack in the wires, so on...You need to find out why you have code 21 any way you look at it.

Just an FYI, fuel pump will only prime when cranking it, for it to actually run, the car needs to be running.

[t.mcginley.jr]

You will not always hear the fuel pump in a vehicle. Don't go by just that. Code 21 is ignition, has nothing to do with the fuel pump. What you need to make sure if all the grounds are connected at the back side of the plenum, if they are not connected, this has been known to fry the PTU, whether its old or new. I would also look at the connections make sure there is no green crud and they are connected nice and tight no crack in the wires, so on...You need to find out why you have code 21 any way you look at it.

Just an FYI, fuel pump will only prime when cranking it, for it to actually run, the car needs to be running.

This is what I was thinking, but I couldn't remember the part about what caused the PTU to fry. Good catch!