ksousa

LS1 swap. 2001 5.7

I have 12V at each coil at the pink wire of the connectors with key on.
I have ground at the brown wire of each.

I don't think I"m getting instructions from the PCM to fire the coils. I do have 170 RPM through the OBD while cranking so seems the crankshaft sensor and wiring are ok.

What test might I perform to see if the PCM is actually trying to communicate with each coil?

thanks

LilJayV10

iTrader: (39)

So I'm guessing you are having a crank no start issue?

If you are getting a RPM signal that indicates the CKP is working and the PCM is seeing it.

Is there a reason you are thinking it isn't getting spark but getting fuel?

Checking to see if you are getting an injector pulse from the PCM is easy, I'd have to look at a wiring diagram to be able to say what you need to check for a coil pulse though.

ksousa

Yes sir. Crank but no start.
I have another, very detailed thread with my symptoms and tests results but it was getting lengthy so I thought I'd try a specific test question.

I'm looking at the coil pulse area because with timing light hooked up and cranking, I get no flash.
I also hooked a spark plugs inline tester and again, no spark during crank.

I do have 12v everywhere necessary during crank, which is a common mistake.

So I'm trying to back up from the coil to pcm to see if the coils are getting instructions to fire or not.

LilJayV10

iTrader: (39)

Are you getting an injector pulse?

ksousa

I think I'm getting injector pulses.
First time using NOID lights and I see a pulse of light when I first engage the starter and I see another pulse of light when I left off the starter, every time.
Typically while the starter is cranking, I'm not seeing the pulsing light.

G Atsma

Sounds like it's wired wrong. No power while cranking, only in Run position.

pdxmotorhead

Put in run position and crank via jumping the starter relay. See if the noids still quit flashing..
The starter bypass circuit may be hosed in the ignition switch or somewhere along the way.
Always check all the fuses..

LilJayV10

iTrader: (39)

You need to take a step back and go to the basics.

That's not how an injector pulse behaves when everything is working properly.

A lot more information is needed to correctly diagnose your problem.

I'm sure there will be people in here that will tell you what' wrong with it with no factual basis and lots of guesses, but that's the internet.

Starting off, verify all fuses, B+ power and ignition power while cranking.

Grounds are just as important as power. There are probably at least 30 questions I'd ask you if you came to my shop with this issue.

ksousa

I am fairly new at this but see my other post. I feel like I've done a fair amount of testing and learning. I was just trying to see if there was a specific test to see if PCM was sending a spark request to each coil so I could rule in or rule out that part of the process.

https://ls1tech.com/forums/pcm-diagn...rt-thread.html

Project GatTagO

iTrader: (7)

Pull a plug...have the coil wire on the plug...hold plug against the block or head...crank the engine...watch for spark...

Andrew