steel1849

My 2001 suddenly developed a startup problem:
When I turn it on, the engine goes into a cycle of revving up a couple of hundred rpm, then drops to idle; up and down, up and down.
I haven't driven it since this started, so I don't have any further symptoms.

Where should I start looking?
steel1849 (newbie)

mishkaya

First, welcome to the forums.
I would suggest checking for codes first. To do this you cycle the ignition key from stop to run (not start) three times; on the third time leave the key in the run position and codes will appear in the odometer window. Report back with results.
mishkaya

steel1849

Thank you; glad to be here.

The code is P 1693.

Do I need to buy a code reader, or is this enough information?

Thanks for your help.
-Steve

mishkaya

Code 1693 by itself means nothing unfortunately, as it is just a companion code. How long have you had the truck, and where are you located? The reason I ask, is because if you are in a colder climate and the grid heaters are functioning already (scary thought), you will get these symptoms; along with the voltmeter dropping and the lights dimming.
mishkaya

steel1849

I bought it new, and the heaters don't come on very often in Houston. It has about 75K miles (I mostly drive it on trips).

I will crank it up and watch the voltmeter.

-Steve

rage_blue

Maybe Check the lift pump pressure. Try checking the obvious like air filter, feul filter and make sure it has feul in the tank and the guage isn't lying to you.

mishkaya

Once you have checked the obvious as rage_blue has stated, and you are sure you have good fuel pressure to the injection pump, you will need to start checking a few other things. First would be an APPS reset (you can find the how-to in the wiki section). Then I would think hard about the Cam Position Sensor as it sends signal to the ECM .
Sorry to have insulted your intelligence in the prior post, but without enough information I couldn't know. We get these questions from new owners every year as soon as the weather starts to turn cold.
mishkaya

steel1849

No insult given or taken.
I was trying to find some humor in the situation.

I will start testing. Thanks for the guidance.
-Steve