Need help with possessed Lexus

I recently bought a 2006 Lexus GX470 (basically a fancy 4Runner) with 77,000 miles on it. When I start the car, one of three things happens…

5/10 times - starts normally
4/10 times - engine turns for 3-5 seconds before firing up
1/10 - engine turns for the 3-5 seconds but doesn’t start

Also, in the few weeks I’ve owned it, the car has started 4 times on it’s own if I do random things like lock the doors. As soon as you stick the key in or try to do anything to try and drive it the engine stops.

I did take it to a very reputable local shop and of course it did not replicate the behavior in their care. They discovered an aftermarket electronic system of some sort that was tied to the ignition. They pulled the power source from it just in case it was the cause.

Before I trudge down to the shop again, looking for best guesses and/or exorcism.

Does this have a factory installed remote start? Or is that what the “aftermarket electronic system” is? If it does start on its own by things like locking the doors than that has to be from a remote start system. Unfortunately those aftermarket installs can create really annoying and difficult problems.

I’m not sure that’s related to the variable crank times though. For the next 10 times you start it up, turn the key to the run position without cranking (just to where all the dash lights come on). Wait a couple of seconds and go back to off. Then back to run…off…run…of etc. Do that about 1/2 dozen times then turn the key. This fully primes the fuel system up to pressure. If that gets it to fire right up 10/10 times then you’re headed for needing a new fuel pump.

Pulling the power to the remote start system may not be enough. If they hacked the wiring up to install it, it may need to be put back to its original state.

I agree with the two previous posters that the problems are likely the result of that remote start system AND the way that it was installed.

A friend of mine experienced the most bizarre assortment of electrical problems that you could possibly imagine, and it was the result of a remote start system (actually, the genuine Toyota remote start system) that had been improperly installed on his brand-new RAV-4. Fortunately, he had the NJ Lemon Law on his side because it was a new vehicle, and the equipment had been installed by the dealership.

I had some fun submitting demand letters to Toyota on his behalf, and they eventually sent a factory engineer and the regional service supervisor to the dealership in order to figure out the problem. If they hadn’t repaired it out on that 3rd try, he would have qualified for a full refund under the terms of the NJ statute, and they wanted to avoid that by sending in the big guns.

Unfortunately, the Lemon Law will not help in your situation, but this little tale that I related is an example of how difficult it can be to find–and resolve–problems like this.

The trouble could be due to an ignition issue or a fuel delivery issue. You may have a weak fuel pump just as a guess. Have the fuel pressure checked and replace the fuel filter also. To see if this is a fuel issue you could keep a can of starter fluid with you and spray some into the intake to see if that makes any difference the next time this happens.

Do you have an original OEM Toyota Key? Or do you use a key made by a lock-smith?

Thanks for all the feedback. I’m not really sure what was installed by the previous owner. There is a switch of some sort on the lower part of the dash below the steering wheel. But all I have is the OEM key.

If you have only one key, I strongly suggest that you get a second key programmed for the car and keep it in a safe location. The security system makes it easy to add a key if you have at least one already programmed, but becomes expensive if the only key becomes lost or broken. I’ve seen it too many times.

My vote is for the aftermarket wiring as the culprit.

Update…car went back to the shop. They diagnosed it as the aftermarket remote start system was causing issues. They completely removed the system. Picked it up today and it started like a champ. Of course it did the same the last time I picked it up. I’ll keep you posted if it relapses.

Thanks for the feedback. I’m now trying to remove an “aftermarket” remote starter from my uncle’s Solara. He was stranded one too many times with this POS system and now I get to remove it. The company no longer answers their phone or emails. They’re probably making socks or radios now.