1999 Lexus ES 300 was towed to the shop after an owner had removed the upper intake assembly in order to install new knock sensors. The engine now does not run at all. It took a good bit of checking and searching but in the end the problem was very simple. Here are the symptoms: the engine cranks but will not run, there is spark present but there is no fuel injector pulse, the engine will run if external fuel supply is added, the engine control computer communicates and data is present, the customer stated that the check engine light was on at one time even with the key off.
The fix was locating and reinstalling a very important missing ground located at the passenger side of the engine near the firewall. The ground had dropped down and went out of site under the a/c lines. The following are several pictures of the ground location.
A very important lesson, with today’s technologies take pictures of your work before you start taking it apart so that you can document where everything goes when you are reassembling.