1998 Chevy Blazer

124,000 MILES • 6 CYL • 4WD • AUTOMATIC
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DIANE0147
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  • 1 POST
I have a 1998 Blazer that runs good a few days then it will miss out real bad and lacks power it always runs good at idle and in park. I have replaced fuel pump and central port injectors. Fuel pressure looks good. No vacuum leaks that I can see. After we installed the central port it was good for 3 days had more power then on the 4th day its missing real bad when you give it gas at any speed. Its not getting a check engine light like it did the last two repairs. It has a 4.3 vortec engine with a 124000 miles on it.
Mar 7, 2009 at 4:26 AM
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IMPALASS
  • ✓Experienced Mechanic
  • 3,112 POSTS
Hello –

To better assist you what is the 8th digit of your VIN.

If I understand you correctly…….you have checked for codes but there hasn’t been a light?

If you haven’t seen a light and have not checked for codes, it may have thrown one. Please go to Auto Zone (AZ) or O’Reilly’s (OR) and for FREE they can pull the codes to the car. Most important: Once they check your codes, if they find something and you don’t get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad. Then make sure you give us all of that. While there for FREE also they can bring their tester out and check your battery and alternator.

It will be interesting to see what they say about the battery and alternator.

Did you change the fuel filter when you did the pump?

Next time it starts acting up, we need to figure out if it is electrical or fuel related (even though you just changed the pump etc). Pull a plug wire off of the spark plug and insert something into the end of it and have someone try to start the car and have the metal object really close to a piece of metal on the engine and see if you are getting a good strong popping blue spark. Don’t have your hands on any part of the metal!!! If there is no spark, then it is electrical.

Next, when the engine is at operating temperature – get a spray bottle of water and mist all over the plug wires…….let me know what you fine.

Check those things and let me know the above…….it may be a MAP sensor or Throttle position sensor also………let’s start with the above.
Mar 7, 2009 at 10:16 AM
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