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start problem


Ami
12-12-2012, 04:17 PM
i have a 1997 grandprix gtp drove to work coming back home did not start
so when i take out the fuel pump fuse and put it in again it started for a few
days then i have same problem again is it the fuse or fuel pump or something
else

Tech II
12-12-2012, 07:27 PM
I assume it cranks, but doesn't start?

Have a can of carb cleaner handy.....when it won't start, spray into the intake.....if it doesn't start, and it's above 40 degrees, then it's a fuel delivery problem...either no fuel pressure or the injectors aren't firing....

Pulling the f/p fuse could have just been a coincidence....

Ami
12-13-2012, 12:52 PM
I assume it cranks, but doesn't start?

Have a can of carb cleaner handy.....when it won't start, spray into the intake.....if it doesn't start, and it's above 40 degrees, then it's a fuel delivery problem...either no fuel pressure or the injectors aren't firing....

Pulling the f/p fuse could have just been a coincidence....


But when i try to start i dont her the humming noise of fuel pump
that when i take out the fuse and put it in again i hear it.
Then after that it starts

Tech II
12-13-2012, 01:28 PM
Is the fuse located in the engine compartment? If yes, and it doesn't start, instead of taking the fuse out use the palm of your hand to give the whole fuse block a tap with your hand....if it starts, you have a wiring problem underneath the UBEC....

Ami
12-13-2012, 02:04 PM
Is the fuse located in the engine compartment? If yes, and it doesn't start, instead of taking the fuse out use the palm of your hand to give the whole fuse block a tap with your hand....if it starts, you have a wiring problem underneath the UBEC....


The fuse is located in the engine compartment
whats a ubec ?
Thanks for your reply

Tech II
12-13-2012, 07:37 PM
Underhood Bussed Electrical Center.....GM's fancy name for the fuse/relay center in the engine compartment...

There are bolts that hold the rear harnesses in place on top...make sure they are all tight....have seen them come loose and cause electrical problems...

Ami
12-13-2012, 10:38 PM
Underhood Bussed Electrical Center.....GM's fancy name for the fuse/relay center in the engine compartment...

There are bolts that hold the rear harnesses in place on top...make sure they are all tight....have seen them come loose and cause electrical problems...

one mechanic said it could be mine wires and plugs

Tech II
12-14-2012, 10:45 AM
Have you checked for codes?

OK, I assume the car is cranking over but not firing.......

If sometime you don't hear the f/p run when you turn the key, and then it doesn't start, how can it be wires and plugs?

Have to have compression, which I doubt is your problem.....

So let's say the fuse part is just a coincidence.....

You need spark and fuel delivery......

So if there is no spark, it could be wires/plugs.....could also be coil(s), ICM, crank sensor, wiring harnesses, etc.

If you have spark, and it doesn't start, then you have either low/no fuel pressure(either bad pump or circuit to it is bad, no power) or the injectors are not firing......also try cranking it a little longer, in case the relay is bad and it takes time for the oil pressure switch to close....

Does ignition key have a black resistor pellet?

Is the engine, just a naturally aspirated 3.8, or is it a SC'er? If SC'er, there have been problems with relays and a ceramic resistor.....

Ami
12-14-2012, 10:16 PM
Have you checked for codes?

OK, I assume the car is cranking over but not firing.......

If sometime you don't hear the f/p run when you turn the key, and then it doesn't start, how can it be wires and plugs?

Have to have compression, which I doubt is your problem.....

So let's say the fuse part is just a coincidence.....

You need spark and fuel delivery......

So if there is no spark, it could be wires/plugs.....could also be coil(s), ICM, crank sensor, wiring harnesses, etc.

If you have spark, and it doesn't start, then you have either low/no fuel pressure(either bad pump or circuit to it is bad, no power) or the injectors are not firing......also try cranking it a little longer, in case the relay is bad and it takes time for the oil pressure switch to close....

Does ignition key have a black resistor pellet?

Is the engine, just a naturally aspirated 3.8, or is it a SC'er? If SC'er, there have been problems with relays and a ceramic resistor.....

There are no codes

The key does not have black resistor

it is a 3.8 gtp supercharged

when i hear the fuel pump humming noise i know it going to start
first time

Tech II
12-15-2012, 08:30 PM
There are no codes

The key does not have black resistor

Ok, then there is no PassKey system, but could have a PassLock system....

it is a 3.8 gtp supercharged

when i hear the fuel pump humming noise i know it going to start
first time

Well, then it is pretty cut and dried that when there is no humming noise, the vehicle won't start.....even if it has a PassLock system, it would have nothing to do with the fuel pump......

So, either there is an intermittant problem with the fuel pump, or the pump is not getting power......this can be caused by a wiring problem or connnection, a bad relay, or bad resistor(the SC'er engine, unlike the regular 3.8 engine, has a resistor in the feed circuit to the fuel pump, to control fuel pump speed.....when higher fuel pump speed is needed, the resistor is eliminated by bypassing it with another relay).......

What I would do, if this is an intermittant problem that may not happen for days, is set up a #194a bulb/socket setup tied to the output of the speed control relay.......if it lights, and the pump doesn't hum, and the harness connector at the tank is ok, and the ground circuit at the harness is ok, then it's a possible pump.....

Ami
12-19-2012, 03:36 PM
There are no codes

The key does not have black resistor

Ok, then there is no PassKey system, but could have a PassLock system....

it is a 3.8 gtp supercharged

when i hear the fuel pump humming noise i know it going to start
first time

Well, then it is pretty cut and dried that when there is no humming noise, the vehicle won't start.....even if it has a PassLock system, it would have nothing to do with the fuel pump......

So, either there is an intermittant problem with the fuel pump, or the pump is not getting power......this can be caused by a wiring problem or connnection, a bad relay, or bad resistor(the SC'er engine, unlike the regular 3.8 engine, has a resistor in the feed circuit to the fuel pump, to control fuel pump speed.....when higher fuel pump speed is needed, the resistor is eliminated by bypassing it with another relay).......

What I would do, if this is an intermittant problem that may not happen for days, is set up a #194a bulb/socket setup tied to the output of the speed control relay.......if it lights, and the pump doesn't hum, and the harness connector at the tank is ok, and the ground circuit at the harness is ok, then it's a possible pump.....

still running has not gave me a starting problem again

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