2000 gmc yukon denali wont start i think because of the security

Have you confirmed that its not a security issue? Did it die suddenly or was it bogging out for a while? Have you scanned the engine?

Have you changed the distributor cap

Use the standard troubleshooting steps at the link below.
Do It Yourself Diagnosis and Repair

My guess would be something electrical that is not working due to the temp. Like a relay.
A relay could loose magnetic power for a few tries then start working.
Or the engine temp sensor could be out of calib and telling the computer the temp is 90 degrees when it is only 50.
You could use a scanner to read the sensors and look for something not right.
Without knowing what is missing in the equation its going to be tough to diagnose it. You really need to know if you are loosing voltage to the coil or the injectors or if the fuel mixture is too lean, etc.

Good question. There are certain things an engine needs to start and run.
> air-fuel mixture
> volumetric efficiency
> compression
> ignition

Which of these things is your engine missing?

Nobody can tell you over the internet without first checking the vehicle out to determine which of these things are missing. Even if we knew which one, there are MANY things that can be the possible cause of each of these things to not be correct.

Plain and simple, the vehicle is going to have to get checked out.

Anybody who tries to tell you any different does not know anything about automotive diagnosis and repair.

I suggest visit this lonk to download 2000 GMC Yukon Denali. Owner's Manual or in this other 2000 GMC Yukon Owners Manual

Hope helps.

According to my lists, 2000 Yukon has a Passlock 2 anti theft security system. This means that the key literally has a transponder in it that sends a radio signal to the ignition. The ignition/lock cylinder then sends a signal to the TDM (theft deterrent module) which then reads the signal and allows your truck to start. If there are any communication breaks, the truck thinks its being stolen and goes into anti theft.... Read up on this link. There might be an option for you. http://vatspasslockpasskeysecurityhelp.yolasite.com/

If it is flooding,fuel is not the problem.Sorry you did a pump already.You need to check spark and air,I would start with spark.Check your plugs for spark.If they all spark normal,that also means the ignition coil is good.That leaves air.Check the filter and intake hose for leaks,holes,etc.I would guess spark,but you never know what you'll find.If you are not 100% sure how to check spark,sounds like you probably do though,just comment on this post and I get an auto email linked to here and tell you the best method.Good luck! Greg

There is a detailed write-up here: http://newrockies.com/vatsbypass. That guy is great, this was the only way I was able to save my Park Avenue.

your getting too much air in chamber on igintion probly cause by a faulty intake and or a faulty tps (throttle positioning sensor) sounds like intake is sucking more air that fuel which is giving a bad air fuel mix in chamber also try checking your mass air could be faulty as well