# Ignition timing question and update on progress with ‘01 Altima



## commuter kw (May 22, 2020)

I inherited this ‘01 Altima about two years ago with 59k original miles. Neither of my siblings wanted anything to do with a 20 year old car. It is a 4 cylinder with automatic and it’s a GXE model. I’m now getting it ready for my teenager to daily drive to college in the fall. It had numerous oil leaks, I believe the car was barely used the last 7 or 8 years. Interior looks brand new and body is excellent apart from both bumpers with minor damage.
I discovered oil leaks from a power steering hose (the one going from reservoir to the pump), the valve cover gasket, the front crank seal and from inside the distributor . I have fixed all those and now no more leaks. 
I next updated the front end with some oem style fog lights. The car was pre-wired, with the wires under the bumper. After installing the lights and cutting out the holes in the bumper, I installed a new relay in the fuse box located in the engine compartment, as well as installed a new combination turn signal, headlight, fog light switch on the steering column. That switch also had the pre-wiring under the steering column cover. The new fog lights work great. Then I took out the original single din stereo and replaced with a double din Boss brand multi media receiver withe apple car play. I wired the apple car play connector to the upper part of the center console, in order to keep all wires and cable hidden. It has total voice controls for music, making calls and getting directions and works great.
Back to the engine:

When I installed the new distributor (I bought a TRQ brand about $120) the car started up and runs fine, however I still need to set the basic timing. I have done this procedure on my ‘91 Sentra, and I researched and found the procedure is the same. After warming up motor, you need to shut it off and disconnect the plug for the throttle position sensor. On my Sentra there is only one plug there, so it’s easy. However I noticed there are two plugs (sensor connectors??) at the TPS on my Altima. The upper plug is brown in color, the lower one is gray. Which one do I disconnect to put the engine in timing mode? My Haynes manual just says disconnect the plug without specifying which one, or do I need to disconnect both?
Thanks for listening to all the updates. BTW this is my first Altima and I will say it drives and handles really nice!


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## rogoman (Dec 16, 2004)

To answer your question; unplug both connectors. Here's the description of the TPS from the FSM:

COMPONENT DESCRIPTION
The throttle position sensor responds to the accelerator pedal
movement. This sensor is a kind of potentiometer which trans-
forms the throttle position into output voltage, and emits the
voltage signal to the ECM. In addition, the sensor detects the
opening and closing speed of the throttle valve and feeds the
voltage signal to the ECM.
Idle position of the throttle valve is determined by the ECM
receiving the signal from the throttle position sensor. This sen-
sor controls engine operation such as fuel cut. On the other
hand, the “Wide open and closed throttle position switch”, which
is built into the throttle position sensor unit, is not used for
engine control.


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## commuter kw (May 22, 2020)

rogoman said:


> To answer your question; unplug both connectors. Here's the description of the TPS from the FSM:
> 
> COMPONENT DESCRIPTION
> The throttle position sensor responds to the accelerator pedal
> ...


Thank you for the clarification. I will try to set the timing this weekend and report back on the results.


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## commuter kw (May 22, 2020)

rogoman said:


> To answer your question; unplug both connectors. Here's the description of the TPS from the FSM:
> 
> COMPONENT DESCRIPTION
> The throttle position sensor responds to the accelerator pedal
> ...


Update:
Your information was spot on. Even though I tried to install the new distributor in exactly the same position as the old one, it was still a good 12-15 degrees off (too advanced). Anyways, your information helped me get the timing dead on to 20 degrees btdc and the engine now starts easier and runs noticeably smoother. Thank you Rogoman!


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## rogoman (Dec 16, 2004)

Glad to help!


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