Impala Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
82 Posts
Discussion Starter #1
I am on my 3rd fuel pump for 2004 Chevrolet Impala. Car has over 196K miles on it now. Had it since 63K when purchased used at the auto auction. I sprayed some brake cleaner into the throttle plate and it would start up fine and run but I didn't let it run long only less than 2 minutes because I was about to change my filter. Then I think ok maybe this ain't the fuel pump problem. I went on to replace the fuel filter and I've put a lot of miles on this car since I use it for Uber and Lyft. Keep in mind I do replace my fuel filter annually since I had this car. After doing that, i primed the car but it still won't start. It'll crank though, but won't start. When I put the key on I hear the fuel pump but doesn't sound very strong like it should, maybe its getting weak. I mean that's crazy since I just put this fuel pump less than 2 months ago from Advance Auto parts. This is the Carquest blue box fuel pump. But what is interesting is that when I relieved the fuel pressure to change my filter, fuel does come out of that fuel rail. Hmm something isn't adding up. But anyways my rant is all over the place lol but if anyone know what I should do, please let me know. Also I replaced the fuel pressure regulator in 2015 so that can't be it.

Oh and there is no MIL illuminating just only when key is on but not while engine is running.
 

·
Registered
Joined
·
2,292 Posts
First thing to do would be a fuel pressure test. That would tell a lot. I would start there and work from there.
 

·
Registered
Joined
·
1,075 Posts
May or may not be a fuel problem, but since you have had issues with fuel pumps, would probably also start with checking pressure. If you have sufficient pressure, would move on to ignition, check spark, could be an issue with ignition control module or coil packs.

With the problems with fuel system in the past, a question I would look at is whether you have used the same gas stations?
 

·
Registered
Joined
·
82 Posts
Discussion Starter #4
Unfortunately, I do not have tools to check fuel pressure or igntion system. An update, I just replaced the fuel pump with a Delphi brand. Still doing the same problem. However, I sprayed brake cleaner into the throttle body and it would start up. I had to floor the throttle to get it to start. And also I hear a pulsating sound from my IAC valve when I had the key on. Is that a problem?
 

·
Registered
Joined
·
1,075 Posts
Unfortunately, I do not have tools to check fuel pressure or igntion system. An update, I just replaced the fuel pump with a Delphi brand. Still doing the same problem. However, I sprayed brake cleaner into the throttle body and it would start up. I had to floor the throttle to get it to start. And also I hear a pulsating sound from my IAC valve when I had the key on. Is that a problem?
With what you say there, can rule out ignition system problem.

No code, would seem it would be unlikely to be a sensor, but possible.

Repeat fuel issues in my limited experience have typically been component failures or issues with bad gas that has or is causing the issue. Which is the case for you with your car I don't know, but sure would not hurt to clean what you can, throttle body, injectors, etc.

Unfortunately ethanol in fuels in my experience can cause damage to fuel systems not intended to run on it. While I have not first hand had major failures with fuel systems in cars or trucks due to gas with ethanol, I have had plenty of experience with damage done by gas with ethanol and rebuilding or replacing small engine carbs due to damage caused by gas with ethanol in it.

Could be something like rust or trash in your tank that stops up or partially obstructs flow to the pump, which limits the fuel getting where it needs to be. Hard to say for sure, but having the fuel pressure checked would help you know better whether the pumping system is working as it should be.
 

·
Registered
Joined
·
82 Posts
Discussion Starter #6
With what you say there, can rule out ignition system problem.

No code, would seem it would be unlikely to be a sensor, but possible.

Repeat fuel issues in my limited experience have typically been component failures or issues with bad gas that has or is causing the issue. Which is the case for you with your car I don't know, but sure would not hurt to clean what you can, throttle body, injectors, etc.

Unfortunately ethanol in fuels in my experience can cause damage to fuel systems not intended to run on it. While I have not first hand had major failures with fuel systems in cars or trucks due to gas with ethanol, I have had plenty of experience with damage done by gas with ethanol and rebuilding or replacing small engine carbs due to damage caused by gas with ethanol in it.

Could be something like rust or trash in your tank that stops up or partially obstructs flow to the pump, which limits the fuel getting where it needs to be. Hard to say for sure, but having the fuel pressure checked would help you know better whether the pumping system is working as it should be.
No code, would seem it would be unlikely to be a sensor, but possible.

The mechanic, told me there's a myriad of codes in the car. One about a knock sensor and evap system (makes sense since I accidentally kinked the evap hose from the charcoal canister to the evap line to engine) that's what he said before clearing to check out the car. He's a Vietnamese mechanic who owns the shop with a funny accent that I can barely understand, but I trust his shop since he has ASE certificates on his wall and licenses from the sate as well as one from California. He also told me it could be a passlock bs, but that is weird as I replaced my ignition lock cylinder with ACDelco part no. D1493F. Programmed it without the Tech 2 scan tool, because I'm not a GM dealership, just an average working American and it fired up. But his argument was that he needs to check the "ohms" going from the BCM, again his accent is so funny I can barely understand him. Now my car is in the shop getting diagnosed.

Repeat fuel issues in my limited experience have typically been component failures or issues with bad gas that has or is causing the issue. Which is the case for you with your car I don't know, but sure would not hurt to clean what you can, throttle body, injectors, etc.


I've cleaned the throttle body on this car often. Perhaps once or twice a year. Also cleaned the MAF with MAF cleaner. Replaced the TB gasket as I had removed my TB to replace my tstat. Clean the heck out that as well.

Unfortunately ethanol in fuels in my experience can cause damage to fuel systems not intended to run on it. While I have not first hand had major failures with fuel systems in cars or trucks due to gas with ethanol, I have had plenty of experience with damage done by gas with ethanol and rebuilding or replacing small engine carbs due to damage caused by gas with ethanol in it.

Yeah, the fuel station that I frequently go to states that there are 10% ethanol in the fuel. 10% ethanol is safe according to advice from experienced technicians.

Could be something like rust or trash in your tank that stops up or partially obstructs flow to the pump, which limits the fuel getting where it needs to be. Hard to say for sure, but having the fuel pressure checked would help you know better whether the pumping system is working as it should be.

No, I've emptied and washed down this fuel tank completely before in October 22, 2015, when I replaced my factory pump with an Airtex E3542M. Replaced it too prematurely in my opinion since I assumed it was going bad because it was making a whine sound after driving for a while. But then again that whine sound came back even with the new Airtex pump. Weird!
 

·
Registered
Joined
·
82 Posts
Discussion Starter #7
UPDATE: The technician told me that he tried almost EVERYTHING. hooked up the BCM, ICM, and swap the FPR, still didn't fix anything. However, he hooked up the fuel gage to the fuel rail and fuel psi went up to 49 psi and then quickly drop pressure to 0. I felt flabbergasted because I installed BRAND NEW fuel pump, a DELPHI brand part no. FG0342. I also spliced in the included wiring harness that was the OE style connector that aftermarket fuel fuel pump manufacturers shouldn't have phuccd with in the first place. He suggested that I should go buy an AcDelco brand which is $200 more and basically the very same part! I'm just at a lost for words. Y'all tell me what should I do. I still have warranty for that Delphi pump.
 

·
Registered
Joined
·
249 Posts
Did your mechanic check power and ground at the pump? You need 12v at 5~10 amps. Good connectors and wires pump to fuse box.
 

·
Registered
Joined
·
82 Posts
Discussion Starter #9
Did your mechanic check power and ground at the pump? You need 12v at 5~10 amps. Good connectors and wires pump to fuse box.
I doubt he did that. But what was strange is after I drove the car home, the fuel pump seems to work as it should. Even after I released the fuel pressure at the fuel rail, the car will start up again.
 

·
Registered
Joined
·
1,075 Posts
He suggested that I should go buy an AcDelco brand which is $200 more and basically the very same part! I'm just at a lost for words. Y'all tell me what should I do. I still have warranty for that Delphi pump.
If it were me and it were in warranty and was basically the same part the mechanic suggested, I would pull it and swap it under the warranty. You however need to decide for yourself what YOU want to do.
 

·
Registered
Joined
·
82 Posts
Discussion Starter #11
If it were me and it were in warranty and was basically the same part the mechanic suggested, I would pull it and swap it under the warranty. You however need to decide for yourself what YOU want to do.
I just did that and also replaced the throttle position sensor with an AcDelco brand for good measure. Still won't start up! GOSH im really at my wit's end with this car. I'm guessing its my PCM that is finally gone bad. THere's my video of me ranting what I did.

 
1 - 11 of 11 Posts
Top