04 impala 3.8L no power to fuel pump

[weldasahobby]

I have a 2004 chevy impala that has been sitting for a few months and it was running fine untill yesturday that I went to start it and I did not hear the pump prime sure enough it only cranked but never started. Checked for power to the fuel pump plug and there's no power to it. Also checked for fire to spark plug and it has good spark. Sprayed starting fluid in the intake and it did not even try to start. I'm kind of lost at this point any help will be greatly appreciated

[Levithan9]

Sounds like a security issue. First and foremost...MAKE SURE YOU HAVE A WELL CHARGED BATTERY !!! A low or almost dead battery will cause all all kinds of hell on the security module.

Next, put the key in the ignition...wait 3 seconds, turn to ON, wait 3 seconds, then try to start. As your starting, look for a security light or symbol to start flashing. If you do see one flashing, then the security system has "lost" it's memory of the key transponder codes.

If that's the case, let me know, and I'll walk you thru reprogramming the keys.

[maxwedge]

If it cranked most likely the security system is not the issue. If you have spark it should have at least tried to fire with starting fliud.

[weldasahobby]

Originally Posted by Levithan9

Sounds like a security issue. First and foremost...MAKE SURE YOU HAVE A WELL CHARGED BATTERY !!! A low or almost dead battery will cause all all kinds of hell on the security module.

Next, put the key in the ignition...wait 3 seconds, turn to ON, wait 3 seconds, then try to start. As your starting, look for a security light or symbol to start flashing. If you do see one flashing, then the security system has "lost" it's memory of the key transponder codes.

If that's the case, let me know, and I'll walk you thru reprogramming the keys.

I forgot to mention when I put the key in the ignition switch I got to move the stearing wheel just a little to turn the switch. Do tou think it could be the switch or maybe the key. I haven't been able to work on it since its been raining all day.

[weldasahobby]

Originally Posted by maxwedge

If it cranked most likely the security system is not the issue. If you have spark it should have at least tried to fire with starting fliud.

That's what I thought it should do. But it didn't ever try. We had that problem on my brothers tahoe. And putting new spar k plugs fixed that but his pump was priming.

[rhandwor]

Originally Posted by weldasahobby

I have a 2004 chevy impala that has been sitting for a few months and it was running fine untill yesturday that I went to start it and I did not hear the pump prime sure enough it only cranked but never started. Checked for power to the fuel pump plug and there's no power to it. Also checked for fire to spark plug and it has good spark. Sprayed starting fluid in the intake and it did not even try to start. I'm kind of lost at this point any help will be greatly appreciated

Lay a finger on the fuel pump relay. Have someone else try to crank it does the relay pulse. If it doesn't pulse try a relay swap maybe a fan relay if it fits. If it starts purchase a new relay.

[Tech II]

Yes, Impala's and Tahoe's are practically brothers....

How about doing some actual diagnosis?

It cranks but it doesn't start?

Are there any "B" codes in addition to "P" codes?

You have spark? Have you put a fuel pressure gauge on the vehicle?

Have you checked for injector pulse?

Will car start if MAF is disconnected? Any fuel in vac line to the fuel pressure regulator?

Have we observed the SECURITY light? Turn key to on, don't attempt to crank....does it go out after three seconds? If it doesn't, do you have PassLock or Passkey?

Would help to get some answers to these questions.....

[Black_Blade]

Check to see if all fuses are good and relays also.

[weldasahobby]

after a long time been busy at work working 12hrs 7 days a week I was able to get back and work on this car again. put in a brand new battery in new spark plugs and wires. try to crank it and is still doing the same thing.

I was reading in other threads and I found one that said it could be a crankshaft sensor.

will check for b and p codes tomorrow
and will purchase and fuel pressure gage tomorrow as well
as far as the security light it goes of after a few seconds
so I don't think it has something to do with the security.

once again thanks and sorry it took me so long to answer

[j cAT]

Originally Posted by weldasahobby

after a long time been busy at work working 12hrs 7 days a week I was able to get back and work on this car again. put in a brand new battery in new spark plugs and wires. try to crank it and is still doing the same thing.

I was reading in other threads and I found one that said it could be a crankshaft sensor.

will check for b and p codes tomorrow
and will purchase and fuel pressure gage tomorrow as well
as far as the security light it goes of after a few seconds
so I don't think it has something to do with the security.

once again thanks and sorry it took me so long to answer

you say it has good spark , cranks good, new plugs. no engine run even with the starting fluid this could be a broken timing chain.

a crank sensor would cause no spark. maf would effect fuel/injectors. even if you had no fuel/fuel pump action starting fluid should get it a spit / start for a sec or 2.

if the security light goes out normally then that seems good.

If the ect is open high resistance then you could have a flooded engine ...injectors open too long [-40 F] ...

does the engine crank over at normal speed ? if it cranks faster then MY guess is the timing chain.

[weldasahobby]

Originally Posted by j cAT

you say it has good spark , cranks good, new plugs. no engine run even with the starting fluid this could be a broken timing chain.

a crank sensor would cause no spark. maf would effect fuel/injectors. even if you had no fuel/fuel pump action starting fluid should get it a spit / start for a sec or 2.

if the security light goes out normally then that seems good.

If the ect is open high resistance then you could have a flooded engine ...injectors open too long [-40 F] ...

does the engine crank over at normal speed ? if it cranks faster then MY guess is the timing chain.

It actually cranks at normal speed. I hope its not the timing chain. I checked with the scanner tool and I got a a p0452 code

[Tech II]

Do you have spark, fuel pressure, and injector pulse?

[weldasahobby]

Originally Posted by Tech II

Do you have spark, fuel pressure, and injector pulse?

I do have spark, NO fuel pressure, and I do have injector pulse. also I tried
to crank it and it almost started and it just quit
this time I sprayed starting fuel and it started for a second and cut off?

an auto parts clerk told me it could be the switch! do you think the switch has anything to do with that?????

[rhandwor]

Their is a diagram on the fuel pump relay. Put a jumper across the two hot going to the pump if it runs check the fuel circuit.

[Tech II]

No fuel pressure.....

Ambient air should be above 40F....

Get a can of carb cleaner.......open throttle plate and spray into intake.....shut throttle......wait 10 seconds.....have someone crank vehicle while you spray towards the closed throttle plate....car should run as long as you spray.......adjust your spray, you don't want to flood it...

If it runs, and you have no fuel pressure, it's the pump or the circuit to it......

Disconnect the 4 wire harness at the tank......you will find a purple, grey, black, and possibly black with a white tracer......the fuel pump ground wire will be the thicker of the two black wires....the grey wire is fuel pump power......so attach a test light to the grey and thicker of the two black wires......have someone turn key on....will light for two seconds and go out.....then crank the car....test light will light as long as you crank car.....

If the light reacts this way, you need a pump.....if it doesn't light at all, then you check F/P relay and circuit...