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GM Bob
GM Bob, ASE Master Technician
Category: GMC
Satisfied Customers: 988
Experience:  30 plus years experience as GM technician, ASE Master Technician and GM Certified
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I have. 2000 GMC Sierra z71 Having trouble getting it to run

Customer Question

I have. 2000 GMC Sierra z71
Having trouble getting it to run
Starts and stays on while idling but dies out when I Give it gas
I replaced the fuel pump and filter
Submitted: 1 year ago.
Category: GMC
Expert:  GM Bob replied 1 year ago.

Hello my name is***** for the wait.

What engine do you have? Could post your VIN#

Have you checked fuel pressure?

Do you have any codes set?

Please get back with me

Thank you

Customer: replied 1 year ago.
Pressure was good
Changed fuel pressure regulator as well
It will stay on but struggle to stay on and will eventually die
Expert:  GM Bob replied 1 year ago.

I know you said fuel pressure is good. Can you tell me what it is?

Also does it hold after shutting it off?

Customer: replied 1 year ago.
I replaced the ignition coils, plugs and wires
It idles smooth now it will stay on
Only problem now is when I put it in drive or reverse it starts to shake and sounds like it wants to shut off
Expert:  GM Bob replied 1 year ago.

When you are in neutral can you increase the engine rpm?

Does it run down the road ok?

If yes on both questions.

I recommend cleaning the throttle body and disconnecting both battery cable and touching the together.

This will reset the idle.

Let me know if this helps.

Customer: replied 1 year ago.
in neutral i can increase the Rpm
Customer: replied 1 year ago.
I haven't driven it on the road yet
Cause of the way it shakes when in drive
Expert:  GM Bob replied 1 year ago.

Do you have a flashing engine light when its shaking?

Customer: replied 1 year ago.
Expert:  GM Bob replied 1 year ago.

Ok that tells me that the engine computer is seeing a misfire.

Do you have a scan tool that can show live misfire graph?

Customer: replied 1 year ago.
No I don't have a tool to read that
What can cause that misfire
Expert:  GM Bob replied 1 year ago.

There are several things. Injector or connector at injector,Low compression,I have seen intake gaskets causing a vacuum leak.

Why did you replace the fuel pump? How did all the problem start?

Customer: replied 1 year ago.
The truck just didn't want to turn on
So I went under the truck to see if I could hear the pump turn on
When I turned the key
And it didn't so I replaced it
And it started up
But It was sitting for about months
Before I could get to it
So I dropped the tank of gas and cleaned it out and the lines
Cause the gas was bad already by that time
Expert:  GM Bob replied 1 year ago.

Need to know if all the injectors are clicking. May have a plugged one.

Does the engine sound like it's holding back?

Customer: replied 1 year ago.
Yea if I put it in drive
It feels like it wana to shut off at first but will start going if I give gas
Expert:  GM Bob replied 1 year ago.

Can you tap on each injector lightly with the engine running. May get them working.

Customer: replied 1 year ago.
I cleaned out the maf sensor, touched the battery terminals to reset the idle
And I put some Royal purple fuel injector cleaner
And now I can put it in drive an it doesn't sound like it wants shut off anymore it still shakes when I have it drive though
Now when I give it gas and accelerate
The throttle response is bad
And the check engine light is still flashing
Expert:  GM Bob replied 1 year ago.

If you can find a auto part store that can read code and live data of the misfire.

That would help

Customer: replied 12 months ago.
here is what I came up with so far
3 cylinders aren't firing
I put new plugs wires and coils
If I pull a wire from a plug there is no change in motor sound
But when I do it to the other 5 there is a Change in sound
So I'm thinking 3 injectors aren't working on those 3 cylinders
What do you think
Expert:  GM Bob replied 12 months ago.

Can you tell which 3 cylinders are missing?

Customer: replied 12 months ago.
Expert:  GM Bob replied 12 months ago.

They are all on the same side?

Expert:  GM Bob replied 12 months ago.

When you pull the wire off you do have spark?

Can you take a long rod or screwdriver and listen to each injector. Should here a clicking noise compare it with a good cylinder. With engine running

Customer: replied 12 months ago.
Yea same side
Customer: replied 12 months ago.
all of them have spark
Expert:  GM Bob replied 12 months ago.

It could be stuck injectors

You could have a intake gasket leaking vacuum. If you sprayed carb cleaner around the intake see if it starts to run smooth.

I also have seen the exhaust convert plug causing some misfire. If you pull the front O2 sensor on the side of the misfire. see how it runs

Customer: replied 12 months ago.
I checked if the injectors are all making the clicking sound and yes they all are
Expert:  GM Bob replied 12 months ago.

That's good.

That means the are getting power and ground.

Customer: replied 12 months ago.
if it isn't the injectors
Is there something else that can be keeping the cylinders from firing?
Expert:  GM Bob replied 12 months ago.

Just because there clicking does not mean they can't be plugged

Customer: replied 12 months ago.
Ok so I might have to pull em out and clean em
Expert:  GM Bob replied 12 months ago.

You could see if auto part store has a cleaning kit.

You have to clean them by running them and flushing a cleaner through them

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