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Gm Tech (Cam)
Gm Tech (Cam), GMC Mechanic
Category: GMC
Satisfied Customers: 29427
Experience:  GM Grand Master Technician 2007. 14 year experience.
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Having a problem with my 2009 GMC Acadia. The other day it

Customer Question

Hi,
This is Keith and having a problem with my 2009 GMC Acadia. The other day it started running real rough and the CEL activated and at some point it would flash and go back steady. Smelled of raw fuel from the tailpipe, etc. Checked codes and it was throwing the following, P0300, P0304, P0305, P0306, P3500 & P3539. Had it towed home and did some research and decided to try replacing the spark plugs. Before replacing the plugs, I wanted to move the vehicle but it will not even start anymore. I did replace the plugs and checked one of the coil packs and it was sparking but never checked the rest. I have cleared the codes to start over but am unable to get it to throw a code. Any ideas before I start just replacing parts?
Thanks
Submitted: 11 months ago.
Category: GMC
Expert:  Randall replied 11 months ago.

Hello, I am Randall, Have you had the codes scanned yet? also, have you done anything to try and fix this problem?

Expert:  Randall replied 11 months ago.

I see you added to the description, let me review this

Expert:  Randall replied 11 months ago.

I do not have any information on the 3500 codes, I will opt out

Customer: replied 11 months ago.
Thanks, i too could not find any info on codes from 3500 onward either. Hopefully someone can help
Expert:  Gm Tech (Cam) replied 11 months ago.

Hi there, I am Cam. Sorry for the delay. Let me pull up those codes.

Expert:  Gm Tech (Cam) replied 11 months ago.

The P03500 and beyond codes are phantom codes generated by your scanner. There are no codes of that type in the GM manual.

for your issue, Were they misfiring all the time or just part of the time?

Customer: replied 11 months ago.
Canstantly and vehicle was running bad, shaking, smell of raw fuel and couldn't go more than 20 MPH. Car finally died and has been able to be restarted since. It will crank and run badly for 2 or 3 seconds and die again.
Expert:  Gm Tech (Cam) replied 11 months ago.

Ok, You verified spark on those cylinders?

I am suspecting injector issues. I have seen several of these injectors fail, and to make it worse, they are direct injectors. The test we do to verify those is to check for spark on the cylinder, Then swap plugs and coils to different cylinders and if the misfire does not move , then do a compression test, and if that is good, replace the injectors on those cylinders.

Customer: replied 11 months ago.
It appears that the coil packs are working. I have moved them around but it still will not start so I can't verify if the problem followed. I will try compression check then move to injectors in the next day or two.
Expert:  Gm Tech (Cam) replied 11 months ago.

Ok, that sounds like a plan.
Please bookmark this page so you can easily navigate back to it so we can continue the discussion. This is done by pressing (CTRL D on PC and CMD D on Mac). You can reply at any time for follow up information regarding this issue, even after you rate the site and I will reply.

Customer: replied 10 months ago.
Got another question. Of course the engine will not start, all coil packs good and new plugs. When I pit my DashCommand diagnostics on I am seeing 60 psi on the fuel pump. When i crank the engine, i get 60 psi on the high pressure fuel rail. Shouldn't this be much higher even while just cranking? If so, I guess I could have a bad high pressure fuel pump. Your thoughts? Or should it be 60 psi until it actually starts?
Expert:  Gm Tech (Cam) replied 10 months ago.

It should take more RPM to get the pressure up. If you spray a bit of fuel in the air filter, does it fire for a moment?