Hello everybody! This morning I pop the hood to install my new NGK sparkplug wires and I noticed that I had some little hoses disconnected and I never noticed that and I'm worried about it could you help me identity what are these and what are they for? but well after connecting those little hoses and take it out for a spin the "check engine" light comes on for a couple of minutes then it goes away, then again for a few minutes until i turn it off then right now I start the car and the check engine light is off. are those any sensors? also one connector was unplugged that I think it has something to do with the power steering, everything that was disconnected is circled in red, Thanks in advance for the help.

Oh! almost forgot, also found that the old wire from the distributor that goes to the lower part (sorry don't know the name) very loose and burned

 

the second/fourth pic is a vacuum to the heater water flow valve. yes it is connected correctly. the third...(shrug)
as for the engine light, check your engine codes. there is a link in the general info sticky.
the light may go off, but a code is usually stored in the ecu to be pulled later. it blinks or turns on and eventually off (and eventually on and eventually off, etc...) to let you know there is an issue.

 

As benstoked stated, the hoses are for the heater valve, the valve is electronically controlled, but uses the vacuum to actually open and close the valve. The small round bit on the hose is a one way valve; it stops the heater valve loosing the vacuum when the engine is at full throttle. Reconnecting these should not have caused a CEL, Double check the distributor and wires; you may have disturbed something in that area that is causing the CEL. Check the ECU codes.

The connector on the power steering hose is a fluid pressure sensor, it tells the ECU when the power steering pump is under heavy load so it can maintain engine idle speed. The engine will still run with this disconnected, but you may notice the idle rpm dip if you try to turn the wheel when the car isn't moving of if you turn it rapidly at low speed.

 

just in case you missed it,
http://forums.maxima.org/showthread.php?t=399534
has the info to pull ecu codes yourself.

may wanna pull the battery for about 20 minutes to reset the ecu, and drive for a couple of days normally. if the light comes on, check the codes.

 

The 1st pic is of your ignition coil, which is turned on and off by the power transitor via signals from the ECM. The ignition coil provides the proper high voltage to the distributor.

If the coil wire was burnt, replace it. Also remove the coil and clean out where the coil wire plugs in. You need a good, solid connection. I've seen corrosion in the plug, and after clean-up, had better performance. New ignition coils (from Nissan), tend to be expensive.

Also double check the ignition coil harness corrector (into the ignition coil) for cracks, potentially busted wires and adequate connection.

It is possible this threw your code as the other vac hoses should not have. Pulling the codes will help immensely with troubleshooting.

 

Thank you all for the help! I been trying to locate the ECU but, can't find it! is it possible for a Maxima to run without ECU? did the 90SE had it on different location than the pictures and video posted? Man I feel stupid being unable to find it, I will take a picture of that area and upload here, maybe is covered with something and I ignore is behind some parts or something, Thanks again, I'll post later with a pict.

BTW the CEL is on again and this time it won't go away.

 

You can't find the ECU? You saw these pictures right?

 

Yes I saw them, Sorry I know my mistake now i just read the thread next to this one and figured it out, I'll update later with the code.

 

1. no
2. no

 

ECU throw Code#51 which the table says Fuel injection circuit open, so what's next?

 

checking the resistance on your injectors.

 

is that difficult to do? I have very basic knowledge about mechanics but reading ohms could be easy for me, I have a digital multimeter but I ignore if I have to take out all the injectors to check the resistance or how is the process do get accurate readings, could you please point me into the right direction, Thanks!

 

Could be injectors, could be connector and harness, could be "BR" fusible link.
You don't need to remove the injectors to test resistance, just carefully disconnect the electrical connectors so you don't break the brittle plastic. You will be able to get to all but cylinder #1 w/o removing anything else. Check for connection, corrosion and then resistance. Resistance should be 10 to 14 ohms. If not in this range, you probably have a bad injector, but I wouldn't discount a bad connection or corrosion on a connector.

Of course, check resistance with the engine off and electrical harness disconnected.

Good luck.