mr.c68

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 darn 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 she fired right up! So before you beat yourself up after a major repair then a no start you might want to try this.

MudHippy

Huh?

You mean you didn't have fuel, but you had air and spark.

Not that resetting the ECU is a bad idea. But why didn't that work the first time? And what kind of "safe mode" under what "certain conditions" would cause the ECU to turn off the injectors? None of that makes very much(if any) sense.

BTW, I'm well aware of deceleration, engine over-rev, and vehicle over-speed fuel cutoff. None of which would apply here though. So what the heck are you talking about then?

mr.c68

I had fuel pressure but no signal to fire injectors. I honestly don't know why it wouldn't start as I can find nothing wrong. Whether it makes any sense or not I guess since this solved my problem I am hoping it might help someone else down the road who is in the same predicament.

MudHippy

Whatever works...works.

There's no denying that.

But I'm still a bit trying to figure out how/why?

mr.c68

For the week I spent trying to get it started I wanted badly to know what the issue was. Now that she's running (better than ever I might add) I'm just happy. Ignorance is truly bliss! By the way Mud Hippy unbeknownst to you I have gotten plenty of good advice from you on this here site in regards to the 3.0 and for that I thank you.