No start after engine rebuild

You can play with your techy gadgets all you want...

But HE SAID IT STARTED with starter fluid.

So why not start with WHAT HE SAID? (facepalm)

 

I don't disagree with you that it is a fuel issue, injectors are part of the fuel system.
Yes we know it tries to run on starting fluid but the PCM is not firing the injectors, you can have all fuel you want to them but if they aren't being commanded on it doesn't matter how much fuel pressure there is.
We have ruled out security and we know we have power at the injectors, PCM controls the ground so we are left with a missing or invalid signal to the PCM, all 6 injector control wires are broken (unlikely), or a failed PCM (also unlikely). Since we see that the RPM signal is erratic at best it looks like a missing or bad crankshaft position signal.
The PCM at a minimum has to have a valid crankshaft position signal to know when to fire the injectors and coils, it will run without the cam sensors.

How do you propose figuring out why the PCM isn't firing the injectors if we can't verify it's getting the correct signals in?

 

Strange case for sure.
I’m kind of amazed it has spark.
You’d think it would kill spark too?

But we’re getting somewhere, that crank signal doesn’t look good.
Progress is being made

 

Sounds like the wire harness is causing electrical gremlins. Next time you pull the engine, know that the wiring harness doesn’t have to come off as the service manual suggests. As a fellow shade tree mechanic, I wish you good luck.

 

OP said a shop did the swap.
OP is stuck fixing the shops mess.

 

I read the post. I get a feeling next time he swaps an engine, he won’t be taking it to the shop. He might find that info useful.

 

Remember, you're looking at an RPM readout...not a scope capture of the CKP or CMP...I'm seeing that graph showing greater than 50rpm for a few seconds, which is what I'd expect to see while cranking. The time base and amplitude of the graph are all out of wack...need to zoom in on time and zoom out on RPM and it will look much more like we'd expect to see

Injector firing strategy is as follows:

As the engine is cranked, the ECM looks for the STA signal, which indicates that the engine is cranking. Basic injection is calculated using the engine coolant temperature sensor (ECT) as primary input.

Next the ECM looks for a crankshaft position signal to determine injector sequence and the crankshaft speed signal to determine pulse frequency.

Finally, the ECM compares the ignition confirmation (IGf) signal with the ignition trigger (IGt) signal to confirm that ignition events are taking place.

If these signals are all present, the ECM will pulse the fuel injectors (#10,#20….#etc.) based on a starting enrichment program.



You're not gonna have much luck confirming IGf and IGt without a scope, or at least a graphing multi-meter (like an OG Snappy Vantage), but you can look through your PIDs to see if the ECM is receiving a STA (start) command. It should be, but stranger things have happened.

Before you do ANYTHING else though....I'd grab a voltmeter and voltage drop test from the negative battery to the ECM grounds,

 

True, although I'd expect to see more than 50 RPM cranking unless the battery was super weak, typically 150-200 RPM cranking would be about right.
I agree it would be much better to be looking at the crank and cam signals on a scope though to see if they are correct.

 

There is more than 50rpm, we just can't see it because he ran outta screen lol

 

I don’t think so.
Most scanners take the peak measurement and set it as the “top” of the graph.
Divide 57 by 4 and you’ll get just what the graph shows on the scale.

 

Could be, maybe the OP will come back and clarify.
Not sure of any other reason the PCM wouldn't fire the injectors other than not seeing the correct signals.

 

Autel doesn't auto range their graphs, they go to a default scale although one can manually set the range as well as zoom in and out.

 

A default of 57?
That is an odd number?
And 14.25 rpm per division?
Talk about “weird”……..

 

Its a chinese copy of a chinese bootleg of a tool that makes sense....there will be some oddities. lol. One of my scanners resets the radio clock to 4:00 every time I try to autodetect the VIN.

 

I can’t either.
Well, I could. But the likelihood of it being any of those is slim.

 

Well it's zoomed in x8 on the X axis, I missed that earlier.

 

Now that is an oddity. And an annoyance.

By the theme OP figures out how to use that scan tool, and what’s wrong with his truck.
He could probably walk into most shops and get a job. And know more than half the people in the shop.

 

Yea they have their quirks but overall they tend to be quite good.
I've had good luck with my Autel, it definitely beats the hell outa my Snapon as far as functionality goes but I do dislike the graphing.

 

I picked up a CanDo C-Pro a while back and I've been very happy with it....certainly not ideal and requires some creative translation here and there, but the graphing is pretty damn good. The Chevy has been parked most of the time since I got the tacoma so its rare that I pull out the scanner anymore lol

 

Well I know it will start/stall and set P0351-P0356 codes if all the IGF signals are missing, tested this on my own when I was writing up troubleshooting for P035x codes.