How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Amedee Your Own Question
Amedee
Amedee, Oldsmobile Technician
Category: Oldsmobile
Satisfied Customers: 23953
Experience:  ASE certified Technician advanced level specialist. Wisconsin certified emissions state inspector
279429
Type Your Oldsmobile Question Here...
Amedee is online now
A new question is answered every 9 seconds

My 2002 Oldsmobile Alero is having starting problems. Help

Customer Question

2002 Oldsmobile Alero - will not start

Have already changed fuel pump.

The car ran for appx. one day

Currently the fuel pump relay #  18 is turning on for 2 seconds when the key is turned to the ON position. This gives me 12 volts continuous back across the pump motor on the other side of the connector that goes up to the fuel pump. I have ohmed out the pump motor and it is the same resistance as the pump. The motor that I pulled which, if I feed 12 volts to, runs (old fuel pump motor). So, I do not believe that the old fuel pump motor was defective.

I hooked 12 volts directly across the fuel pump motor (new) and I cannot hear it running - black being the ground, gray being the 12 volt line

I have spark and no security light is on, no codes are displayed

Question - is there anything that might make the pump not to turn on when fed 12 volts --- (? Is there a pressure switch on the pump that it might pressure up when I turned on 12 volts, causing it to NOT turn on?).

I have also added a new fuel filter with the new pump (new, not rebuilt, pump)

I do not hear the new fuel pump coming on when I put 12 volts across it.

Submitted: 4 years ago.
Category: Oldsmobile
Expert:  Amedee replied 4 years ago.

Hello!
Is the fuel pump getting voltage when cranking the engine over?

Customer: replied 4 years ago.

Yes, pump indicates 12 volts (constant) when turning engine over.

Expert:  Amedee replied 4 years ago.

You are saying that the new fuel pump will not even run when it has power and ground directly supplied to it?

Customer: replied 4 years ago.

Yes, that is correct. Do you know if the fuel pump has a pressure switch that would shut it off if pressure was high -- such as might be caused by a clogged line or a sending unit not returning fuel back to the tank?

Expert:  Amedee replied 4 years ago.

There is no such switch for the fuel pump on this vehicle. The only switch like this is the inertia switch used by Ford vehicles. But this vehicle does not even have any sort of switch like this.
This fuel pump should run with power and ground supplies to it. It is as simple as that. You could remove the fuel pump and see if it runs when bench tested. This would be your best bet.
You could have an issue with the wiring inside the tank or even at the connection at the fuel pump itself.

Customer: replied 4 years ago.

The new fuel pump motor in the car has the same resistance as the motor I took out, measured from the plug so I know whatever caused the original problem that made the fuel pump look like the problem is not the problem. The old fuel pump works in a bucket of water so I have the original problem, but am still looking for the answer.

Expert:  Amedee replied 4 years ago.

A resistance check is not a good test. I have been doing this for 13 years and I have not ohmed out a fuel pump in over 10 years because it is not needed to see if the pump is bad.
If the pump does not come on when you power it up and supply a ground to it at the same time, the pump is bad. It is as simple as that.
If it is not coming on, then either the pump is bad or you have a bad connection between where you are powering it up and grounding it at to where the fuel pump is located.
Your overlooking something.. I guarantee it!

I am assuming you checked for a ground on the black wire correct? If so and it checks out good, then the problem will be the same that we have been talking about. If there is no ground on the black wire, this will be the root cause. If you need the locations, let me know!

Customer: replied 4 years ago.

If the pump is or was pumping, what would cause the car not to start if you have spark? Sprayed starter fluid into the air intake and the car starts for a couple of seconds.

Ground is good. Both pumps have same systems. What caused this to happen? Maybe too high pressure?

Expert:  Amedee replied 4 years ago.

Hello!

You need to check injector pluses when cranking the engine over. You would use a tool called a noid light. It connects to the injector connector after it is disconnected from the fuel injector and should blink when the engine is cranking over.

Customer: replied 4 years ago.

Is there any device that is in path with that gas line that could let the gas pressure in the line become so high that it could ruin the pump because I have lost 2 pumps that will intermittently work outside the car and I provided 12 volts across the gray and black lines (with gray having the 12 volts on it and black having the ground). Would a bad pressure sensor on the pump play into this problem or is there a return valve that releases pressure back to the tank (re-routes). The pressure if it builds too high back to the tank to relieve the pressure -- with spraying starter fluid into the air intake (which starts the car for a brief few seconds PLUS the car ran fine for appx. one day with the new pump). I have to believe that the computer and system is working and is trying to start the car.

Expert:  Amedee replied 4 years ago.

Based on the little information you have given me, it sounds like there is no injector pulse when cranking the engine over. This is usually due to the security system on your vehicle but if this where the case, you would have a security light on or flashing in the dash and a code in the computer related to this condition.

One quick note, if there is no injector pulse, this start stall condition is usually caused by a bad ignition switch. Sometimes this is fixed by doing an ignition switch relearn procedure.
This is the common failure with this vehicle you are most likely talking about.

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
< Previous | Next >
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
  • He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here. Diane Dallas, TX
 
 
 

Meet The Experts:

 
 
 
  • Dave Nova

    Dave Nova

    Oldsmobile Tech

    Satisfied Customers:

    597
    ASE Master Certification. GM World Class Certification
< Last | Next >
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    Oldsmobile Tech

    Satisfied Customers:

    597
    ASE Master Certification. GM World Class Certification
  • http://ww2.justanswer.com/uploads/BL/Bluegorilla/2012-6-21_16298_cam.64x64.JPG GM Tech Cam's Avatar

    GM Tech Cam

    Oldsmobile Certified Technician

    Satisfied Customers:

    402
    14 years Automotive experience all with Gm.
  • http://ww2.justanswer.com/uploads/ggrote1/2009-06-27_031011_me.jpg Gary's Avatar

    Gary

    ASE Certified Technician

    Satisfied Customers:

    159
    over 25 years as a GM master tech
  • http://ww2.justanswer.com/uploads/joecamel90/2008-11-13_03615_head_shot.jpg George H.'s Avatar

    George H.

    ASE Certified Technician

    Satisfied Customers:

    144
    ASE Certified and dealer trained 15+ years
  • http://ww2.justanswer.com/uploads/GU/GUY VAN IDERSTINE/2011-12-6_112234_florida2011005.64x64.JPG jazzmaster's Avatar

    jazzmaster

    ASE Certified Technician

    Satisfied Customers:

    142
    I have 32 years experience as a automotive tech,plus ase certified
  • http://ww2.justanswer.com/uploads/DR/drivefast1971/2012-1-12_172422_0009051tQKh.64x64.jpg Ron Z.'s Avatar

    Ron Z.

    - Olds Tech -

    Satisfied Customers:

    138
    18+yrs experience. State Inspector & Olds Diagnostics/Repair
  • http://ww2.justanswer.com/uploads/tsmodie/2009-6-10_144056_tim.jpg Tim Mohr's Avatar

    Tim Mohr

    ASE MASTER

    Satisfied Customers:

    124
    30 YEARS EXPERIENCE, FORIEGN AND DOMESTIC, GAS AND DIESEL