Ls swap no start

:mad::mad::mad: 5.3 swap in a 78 nova, 400 turbo
I have spark and I have 60 psi fuel pressure
No fuel from injectors !!!!!!!!!!! Changed rails, injectors and fpr!
when I pull plugs they are dry!
WTF am I missing ?????

What is the PCM from and what's the wiring harness from? Modified stock harness or some aftermarket thing? What year/make/model is it pinned for? Do you have accurate diagrams for whatever it's from?

Do you have +12v at one pin of the injector plugs with key on? This power comes direct from a fuse, switched ignition feed and not the PCM.

Do you get a pulsed ground at the other pin of the injector plugs while cranking? If no, are the wires intact from each injector back to the corresponding pins at the PCM?

Thanks blindsquirrel for your reply. 411 pcm 2002 silverado as is engine. Aftermarket harness. Yes I have 12 v at one pin and pulsed grd from other.
I have a wiring schematic and checked everything and could find nothing wrong.
Glen

Post the tune and log it trying to start.

No Start Log And Tune

This is a simple one, so follow me here.

This tune file has had the 3 BAR OS upgrade applied to it. This would be done if you where going to run a 3 bar map sensor for a supercharger or a turbo charger. If that is something you are not trying to do, you should not have applied this upgrade. When you click the OS tab it is now completely blank and it shows the 3 BAR OS upgrade under the calibration details page.

When doing this upgrade it also changes the MAP sensor settings to a generic 3 bar setting and maxes out the VE table. The VE table has to be re-created for it to even want to run.

Also you can't just remove the MAF sensor without failing the MAF in the tune and wiring in a separate IAT sensor that you must have working.


If you do not plan to run boost I highly suggest you flash this file back to stock with a write entire. Then fail the MAF sensor and wire in a IAT sensor. It will run without the IAT but it won't run that well if you just want to see if it starts.

Thank You 5FDP .
I will make changes tonight and post results.

It Runs !!!!!
I have failed the MAF sensor and wire in a IAT sensor.
I have that tune in it now it starts and runs pretty good up top in rpm.
A real dog from idle/ Wont even spin tires.
Stage 2 cam and headers only updates. 78 Nova 400 turbo 3500 stall 3:55 gears.
Attached is tune and log file.
any help is much appreciated.

To put this nicely, why do people go out and just floor it on a completely untuned engine??

Of course it's going to run bad, nothing has been done yet.

Just look at your timing in your log. At full throttle it's running like 3 to 7 degrees of timing, that is where all your power loss is.


The tune needs to have all your EVAP codes, rear o2 codes, all transmission related DTC"s set to no error reported.

Couple more things, this may get long here.

Cylinder volume is wrong, it's current setup for a 4.8 engine, needs to be changed to a 5.3 engine size.

Those stock fuel injectors are likely to be too small in the upper rpm's under full throttle, get an eye on your duty cycle. The data log is missing your injector pulse width avg as well.

The current log also shows a knock sensor code. The log isn't logging knock retard because it's not in the channels list. Any pending or current knock sensor code will tell the computer to yank out 8 degrees of timing the way it's setup in this tune file.

Abuse mode is still on in the engine torque mngt tab. Change that to 7,000rpm and 0 mph. Transmission abuse mode is also still active in the transmission tab. In the systems tab there is a systems options table. In that table there is a section for brake torque mngt, it as a 1 in that cell, change it to zero to turn that off.


The o2 sensors were dead for half that log and I don't see a wideband air fuel ratio sensor being logged. You will require a wideband for tuning this, no if's ands or buts about that. There is no other way to tune without one.

Fix a few of the above things, get a wideband and start reading up on VE tuning. Getting fueling under control is the biggest thing.