Problem starting

[latorawilson]

My 2003 Impala will not start unless I give it gas and will die if I take my foot off the gas. Have anyone else had or has this problem? What could the problem be? I just spend $1000 getting the computer replaced which was supposed to be the problem. Now this happens.

[j cAT]

Originally Posted by latorawilson

My 2003 Impala will not start unless I give it gas and will die if I take my foot off the gas. Have anyone else had or has this problem? What could the problem be? I just spend $1000 getting the computer replaced which was supposed to be the problem. Now this happens.

what was the original problem ? how did you drive away from the repair shop that stole your money...?

[J-Ri]

Remove and clean the IAC valve, sounds like it's stuck shut and not allowing enough air in without you opening the throttle valve partially.

[ChevyCelebrity]

I have the same car with the same problem. I tried cleaning the IAC but it didn't work. No trouble codes, any suggestions?

[j cAT]

Originally Posted by ChevyCelebrity

I have the same car with the same problem. I tried cleaning the IAC but it didn't work. No trouble codes, any suggestions?

Iac has nothing to do with starting.

what is the fuel pressure ?

[ChevyCelebrity]

I finally got a hold of a fuel pressure gauge so I was able to continue to my troubleshooting. I am not sure if I did it right and the gauge seemed a little leaky, but the readings seemed to be right.

I hooked the gauge to the test port on the fuel pressure regulator and when the key was on but the engine wasn't running, the fuel pressure jumped up to about 54 psi, but after the pump kicked off it dropped down to around 46 psi. According to the Haynes manual, the normal pressure for this time should be from 53-59 psi for my motor. After I started the car, to be honest I can't remember what the reading was (I was dumb and didn't take notes). I am pretty sure the reading was a little lower though, but I'm not sure.

The next thing I did was pull the vacuum line off of the regulator. When I did this the pressure jumped up to about 54 psi while it was running, and it dropped back down to 46 psi when I put the vacuum hose back on.

I looked in the book and it said when the pressure is lower check the fuel filter, or install a stop valve on the return line. The fuel filter was recently replaced, so I attempted to install a stop valve. I am pretty sure I installed it on the right line, as it was the one that was coming out of the regulator (not the fuel line on the opposite rail). When I started back up the car the fuel pressure was much higher, around 57 psi. When I stopped the line, the pressure spiked well over 60 so I stopped the test because I didn't want to screw up the fuel system. After I opened the valve back up it dropped back down to 57 psi.

Another item of note is when I first started messing with my car (after it had sat overnight), I pulled the vacuum line off of the regulator. Fuel immediately came out of the vacuum line, which means the regulator could be bad?

I am leaning toward the fuel pressure regulator being bad, but I really have no idea. What do you think? I may need to grab someone who knows what they are doing and re-test the pressure lines.

By the way the car starts fine, it just stalls while the engine is still starting up (but only in some situations). This typically happens if the motor is warm (like while running errands), but not when hot or cold. The car also recently started stalling sometimes when 'idling' while driving, which makes me think this is indeed a fuel problem.

[j cAT]

Originally Posted by ChevyCelebrity

I finally got a hold of a fuel pressure gauge so I was able to continue to my troubleshooting. I am not sure if I did it right and the gauge seemed a little leaky, but the readings seemed to be right.

I hooked the gauge to the test port on the fuel pressure regulator and when the key was on but the engine wasn't running, the fuel pressure jumped up to about 54 psi, but after the pump kicked off it dropped down to around 46 psi. According to the Haynes manual, the normal pressure for this time should be from 53-59 psi for my motor. After I started the car, to be honest I can't remember what the reading was (I was dumb and didn't take notes). I am pretty sure the reading was a little lower though, but I'm not sure.

The next thing I did was pull the vacuum line off of the regulator. When I did this the pressure jumped up to about 54 psi while it was running, and it dropped back down to 46 psi when I put the vacuum hose back on.

I looked in the book and it said when the pressure is lower check the fuel filter, or install a stop valve on the return line. The fuel filter was recently replaced, so I attempted to install a stop valve. I am pretty sure I installed it on the right line, as it was the one that was coming out of the regulator (not the fuel line on the opposite rail). When I started back up the car the fuel pressure was much higher, around 57 psi. When I stopped the line, the pressure spiked well over 60 so I stopped the test because I didn't want to screw up the fuel system. After I opened the valve back up it dropped back down to 57 psi.

Another item of note is when I first started messing with my car (after it had sat overnight), I pulled the vacuum line off of the regulator. Fuel immediately came out of the vacuum line, which means the regulator could be bad?

I am leaning toward the fuel pressure regulator being bad, but I really have no idea. What do you think? I may need to grab someone who knows what they are doing and re-test the pressure lines.

By the way the car starts fine, it just stalls while the engine is still starting up (but only in some situations). This typically happens if the motor is warm (like while running errands), but not when hot or cold. The car also recently started stalling sometimes when 'idling' while driving, which makes me think this is indeed a fuel problem.

replace the regulator. the vacuum diaphram has a hole in it . this will cause a poor start as the fuel can flood the engine and foul plugs[wet].

after this regulator is replaced and it is running better I would replace plugs or at the least pull plugs to view the condition.

fuel pressure test seems good. pump looks good.

[ChevyCelebrity]

I finally had time to replace the fuel pressure regulator, and so far so good. Thanks!

[j cAT]

Originally Posted by ChevyCelebrity

I finally had time to replace the fuel pressure regulator, and so far so good. Thanks!

good luck with it !