SSZ

OK so i just dropped in a 5.3 into my 80 Z28. I was told that the computer has been programmed to run without the emissions. Attempted to start the engine and just cranks. IT has spark. No injector pulse. Checked for codes with my shitty code reader and it has a code 1336. Will this shut down injector pulse? According to what i have read you have to have the engine running in order to do the crank relearn procedure. Any other ideas as to why i dont have an injector pulse? Also i dont have any O2s on yet but again i dont think this would stop the injectors from operating.

MUSTANGBRKR02

iTrader: (91)

Do you have power at the injectors? Make sure that all of the engine grounds are connected and the grounds off of the harness are all connected also.

SSZ

You know what, never checked for power at the injectors. Will the injectors have power going to them all the time? Like how does that work? Does the pcm provide a ground when time to open the injector to inject the fuel?

SSZ

Yes, i do have power to my injectors. I just checked and yes there is also fuel too. Out of the harness i see three grounds that i attached to the bell housing. Do not see any other grounds out of the harness.

MUSTANGBRKR02

iTrader: (91)

Three should be all I believe.

BaddBird

iTrader: (6)

Yes the pcm triggers ground. You need to use a noid light to check for injector pulse as you crank the engine.

edcmat-l1

iTrader: (10)

You check for spark? You have the ground on the back of the drivers side head hooked up?

EDIT: Never mind. Just saw you said it has spark..........

Fuel pressure? Can you hear the pump prime?

SSZ

Yeah. May have to go get a noid light tomorrow. At this point i figure there is no pulse as the engine doesnt even hiccup. We put some raw fuel in the intake and it ran briefly. Someone has played with this harness and its a neat job they have done. I do have one wire left that has not been connected to anything and it is labelled TACH. WHich i think is the wire that would normally go to the cluster for tachometer operation. It is a long white wire. Think i could be wrong in this assumption?

SSZ

Sorry. Just saw that you wrote this. Yeah. Lots of pressure.

MUSTANGBRKR02

iTrader: (91)

You can also pull the rails up and spray the injectors into a few water bottles to be positive.

SSZ

We have fuel pressure for sure. Large spray pattern from the rail test port. The injectors arent injecting fuel. Plugs are all dry. I think the pcm uses the cam sensor for reference as to when to fire the injector??? I have the cam sensor plugged in as i just checked that. I am going to have to find a scanner and see if i can find what is going on here. Is there a diagram somewhere where it shows what pins in the pcm power up or provide power/ground to the various sensors? If i had this i could check for continuity between the various sensors and make sure they all have the necessary wiring with good continuity. Also, i could make sure whoever worked on the pcm and wiring hopefully hasnt removed something they shouldnt have.

BaddBird

iTrader: (6)

If you add fuel (carb cleaner) through the Tb will the car start?

edcmat-l1

iTrader: (10)

You can get vehicle specific info from Auto Zone. They own ALLDATA now.

The cam sensor synchronizes the injectors, but it can run without it. You can unplug the sensor and it will start up.

Need a scanner for sure. That will tell you alot.

SSZ

I put some fuel into the intake and the engine will run. I just grabbed a scanner so i am going to have a look and see what is going on here. Thanks for your help so far. Really appreciated.

MUSTANGBRKR02

iTrader: (91)

http://ls1tuningguide.com/tuninghelpfiles.php

Wiring schematics are here.

SSZ

Had a look with the scanner and found in the data it read
Fuel sys 1 open
Fuel sys 2 open
I am thinking this has something to do with it. NOt sure where to start from here though?
WHen i crank my timing adjusts and i do read an rpm. TPS is smooth. I checked for continuity between my injector...ummm.....ground feed wire i believe cause it does not have power when key on and the pcm connector and all have continuity. Also checked for power at the cam sensor and with key on one terminal has about 12v. Same with the injectors, their power feed is 12V also. Not sure if there is supposed to be a 5v reference in the 3 wires going to the cam sensor or not but the other 2 wires didnt read anything. Any further thoughts?

BaddBird

iTrader: (6)

Continuity means nothing you can have a broken sensor wire with 1 or 2 strands still making contact and have continuity. The only way to truly check a wire is shoot 12 volts through it with a grounded headlight at the other end ( make sure everything is disconnected from the circuit first). If the headlight is bright then the wire is good. You have 12 volts @ the cam sensor are you sure? The 3 wires should be 5 volt reference, signal return & ground. Cam sensor will not usually keep one from starting. Did you ever find out if you had pulse from the pcm to the injectors? Get on the ground side of the injector harness and use a test light hooked to B+ and see if the pcm is pulsing.

SSZ

Yeah. PCM is pulsing. First couple pulses look strong then it weakens. Yes also for the cam sensor. 11.8 volts. I have 3 loops with ground wires attached that come out of the harness and i have those bolted to the block.

BaddBird

iTrader: (6)

Strong pulse then it gets weaker sounds like a connection issue. 12volts on the cmp reference wire sounds like a bad pcm or a short on the positive side. Back probe the cmp sensor reference wire at the pcm and check the voltage. Also check some of the other ref wires on other sensors to see what kind of voltage they have.

SSZ

Will do. I also checked the CKP and it also had 11.8. Will get back in a second.