So after installing new injectors (yellow Bosch 4 hole) I had a no start issue with my 89 4Runner 3vze. At 1st I thought it must be the injectors but a noid light plugged into the injector plug showed no signal getting to injectors. So then I thought I must have forgot a ground wire but after looking it over a thousand times I knew I hadn’t. I had also deleted the A/C & PAIR (EGR already done) so I thought it had something to do with that. While waiting for the injectors I had tested / adjusted the TPS and VAFM so I was sure it had nothing to do with them. Long story short I had Fuel, I had Air, & I had Spark but the damn thing would not start. After reading hours of posts on the subject I finally found something useful. Someone explained that under certain conditions the ECU will go into a safe mode & not send the signal to fire the injectors. So with this knowledge I unplugged the EFI fuse (which I had done before trying to start it the 1st time) & low & behold that B!*%# fired right up! So before you beat yourself up after a major repair then a no start you might want to try this.