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kalamykid
kalamykid, Shop Owner/ Tech
Category: Chevy
Satisfied Customers: 4024
Experience:  I HAVE OWNED MY OWN SHOP FOR OVER THREE YEARS. I HAVE THE TOOLS AND SOFTWARE TO ANSWERE ALMOST ANY Q
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Have A 1997 gmc 1500 5.7 won't start, it has spark, fuel

Customer Question

Have A 1997 gmc 1500 5.7 won't start , it has spark, fuel pressure. Well run on ether but no injector pulse need help
Submitted: 10 months ago.
Category: Chevy
Expert:  kalamykid replied 10 months ago.

If you try to start the engine and then leave the ignition switch in the run position, does the security light flash?

Customer: replied 10 months ago.
No security light also have replaced ignition control module and crank sensor
Customer: replied 10 months ago.
Checked ground on thermostat housing that is also good
Expert:  kalamykid replied 10 months ago.

Do you have scan tool that will show live data from the computer?

Customer: replied 10 months ago.
I'm getting a lost signal while cranking also no codes
Expert:  kalamykid replied 10 months ago.

What signal are you loosing?

Customer: replied 10 months ago.
Scanner says was key on retry, every time I crank over to get data as in rpm, timing, ect.
Expert:  kalamykid replied 10 months ago.

Have you checked the fuel pressure?

Customer: replied 10 months ago.
fuel pressure within spec
Expert:  kalamykid replied 10 months ago.

What was the pressure reading?

Customer: replied 10 months ago.
52 psi
Customer: replied 10 months ago.
On top of intake the injector connector I'd getting power but no ground for injector pulse
Expert:  kalamykid replied 10 months ago.

Have you had the battery disconnected recently?

Customer: replied 10 months ago.
Expert:  kalamykid replied 10 months ago.

Will the security light come on if you turn the ignition switch from off to run?

Customer: replied 10 months ago.
No
Expert:  kalamykid replied 10 months ago.

I need you to check the bcm fuse please with a test light and see if you have power on both sides of the fuse.

Customer: replied 10 months ago.
it is getting power on both sides
Expert:  kalamykid replied 10 months ago.

Have you ever seen the security light come on?

Customer: replied 10 months ago.
No is there a way to reset I can try that maybe the bulb Is burnt
Expert:  kalamykid replied 10 months ago.

If the bulb is burnt out you will have to replace it to reset the security system. It may reset with a bad bulb, but you will not know for sure if the system is ready or not if the light does not work. You can try the reset if you would like with out checking the bulb, here are the steps you have to do to reset it.

Customer: replied 10 months ago.
Ok i will try and get back to you tomorrow thank you
Expert:  kalamykid replied 10 months ago.

You are very welcome.

Customer: replied 10 months ago.
Getting code p1351a
Expert:  kalamykid replied 10 months ago.

Did you get it to start?

Customer: replied 10 months ago.
No changed pickup coil still nothing, suspecting ecm
Expert:  kalamykid replied 10 months ago.

Do you have a piece of wire around a 16 gauge and at least 4 foot long?

Customer: replied 10 months ago.
I do
Expert:  kalamykid replied 10 months ago.

Lets see if we can jump power to get it to start. Look on your computer and see if you have a clear or gray colored plug. In this plug there will be a white wire in pin 9. use a paper clip and run it along side the wire so the paper clip is making contact with the metal pin in the plug, attach one end of your jumper wire to the paper clip, then look at the main plug of the ignition control module and find the white wire in that plug and use another paper clip to jump the new wire in and see if the truck will start.

Customer: replied 10 months ago.
Working on that get right back to you
Expert:  kalamykid replied 10 months ago.

ok

Customer: replied 10 months ago.
Nothing at all
Expert:  kalamykid replied 10 months ago.

And you are sure you hit the correct white wire in the clear plug?

Customer: replied 10 months ago.
9 jump to white wire on ignition module
Expert:  kalamykid replied 10 months ago.

Do you have a digital volt meter?

Customer: replied 10 months ago.
I do not
Expert:  kalamykid replied 10 months ago.

Do you have a test light?

Customer: replied 10 months ago.
Expert:  kalamykid replied 10 months ago.

What I want you to do next will be to unplug the clear plug from the pcm, as well as the ignition module, connect your test light to a good + battery source and the test light on each end of the whit wire and see if the test light lights up.

Customer: replied 10 months ago.
It does light up
Expert:  kalamykid replied 10 months ago.

Then you have a short in the white wire to a ground, you have two options, find the short, or cut both ends of the white wire and hard wire in the jumper wire you where using.

Expert:  kalamykid replied 10 months ago.

The white wire is a dedicated wire from the ignition module to the pcm.

Customer: replied 10 months ago.
Ok i think I misunderstood if I disconnect both wire harnesses and check for ground there is no ground what I did was jump a hot wire on one side to see if the other side was receiving power and not cut
Expert:  kalamykid replied 10 months ago.

ok lets do the correct test, leave both ends unplugged, and with your test light connected to a good battery + and the tip of the test light on each end of the wire one end at a time see if the test light lights up.

Customer: replied 10 months ago.
No does not light up
Expert:  kalamykid replied 10 months ago.

PLug the ignition module back up, turn the ignition switch on and with your test light connected to a good ground, see if the test light lights up when you test the pcms white wire, with the pcm still unplugged.

Customer: replied 10 months ago.
No power
Expert:  kalamykid replied 10 months ago.

Do you still have the old ignition module?

Customer: replied 10 months ago.
I do
Expert:  kalamykid replied 10 months ago.

reconect it and retest please.

Customer: replied 10 months ago.
Same no power to white wire at pcm side
Expert:  kalamykid replied 10 months ago.

now unplug the icm and plug the pcm back up and retest with both modules please.

Expert:  kalamykid replied 10 months ago.

Forget about the module, you will have it unplugged. Sorry.

Customer: replied 10 months ago.
Same results
Expert:  kalamykid replied 10 months ago.

One last test. With the ignition switch in the run position, use your test light connected to a good ground and see if you have power to all the fuses. Do this by touching the tip of the test light to the metal pieces sticking up through the plastic of the fuses. If the light lights up on one side but not the other replace the fuse.

Customer: replied 10 months ago.
All fuses have power
Expert:  kalamykid replied 10 months ago.

Did you test all the fuses in both fuse boxes?

Customer: replied 10 months ago.
14 and 8 have no power in cab every other fuse had power including under hood
Customer: replied 10 months ago.
14 lights up with lights tuned on and 8 lights up while cranking
Expert:  kalamykid replied 10 months ago.

Will the truck still start on starting fluid if you plug everything back up?

Customer: replied 10 months ago.
Will start with starting fluid
Expert:  kalamykid replied 10 months ago.

Can you make sure it still will please?

Customer: replied 10 months ago.
It still well start on starting fluid yes
Expert:  kalamykid replied 10 months ago.

We have a big problem. the test results you have given me say it should not start.

Customer: replied 10 months ago.
With both end of wires unplugged.. ignition control module unplugged and pcm unplugged test light to + no light test light to - no light wire is not cut as I added power to one end and other side had power plugged everything back in same results starts on starting fluid
Expert:  kalamykid replied 10 months ago.

Are you sure you gave me the correct code?

Customer: replied 10 months ago.
that is the only code.. cleared code crank a few times and it's back over and over
Customer: replied 10 months ago.
My main concern is why my scanner is losing data connection while cranking?
Expert:  kalamykid replied 10 months ago.

Unplug the icm and with the ignition switch in the run position, see if the test light will light up when you test all the wires in the icm plug please. Tell me what color wires have power please.

Expert:  kalamykid replied 10 months ago.

That is normal, the ignition switch cuts power to the obd2 port during cranking.

Customer: replied 10 months ago.
2 outer have power 2 inner have no power
Expert:  kalamykid replied 10 months ago.

What color are the wires please.

Customer: replied 10 months ago.
I'll have to recheck I had to leave but If I remember all had power except white wire
Expert:  kalamykid replied 10 months ago.

Then the code has to be caused by a fault in the pcm and it will need to be replaced.

Customer: replied 10 months ago.
That is my guess will order pcm install and I will let you know. Thank you
Expert:  kalamykid replied 10 months ago.

You are very welcome.

Customer: replied 10 months ago.
Replaced pcm now no start at all
Customer: replied 10 months ago.
Ok got it to start on starting fluid so back to control module Red has power white has no power black has no power white with black stripe has power
Expert:  kalamykid replied 10 months ago.

Did you do the relearn on the security system?