Go Back   Blazer Forum - Chevy Blazer Forums > Mechanical & Maintenance > Engine & Transmission
Sign in using an external account
Register Forgot Password?
Search


Welcome to Blazer Forum!
Welcome to Blazer Forum,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to start new topics, reply to conversations, privately message other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join Blazer Forum today!


Closed Thread
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 01-19-2009, 09:59 PM
 
Join Date: Jan 2009
Location:
Posts: 8
allenax78 is an unknown quantity at this point
Send a message via Yahoo to allenax78
Default 99 blazer won't start/ fuel pump not running

I have a 1999 4.3L 2 door 2wd s10 blazer.......i drove it to my kid's school, shut it off for about 5 min. and wouldn't start afterwards. The gas gage hasn't worked in years..(reads at full, less than that erratic and won't go below half). Based on my normal miliage i should have been about 60 miles before i ran out of gas, but that was what it felt like. It started for half a sec. and died. It rolls over but doesn't attempt to start. I put gas in it but I don't hear the fuel pump running with the key on or when trying to crank the engine. I've checked the fuses, and swapped relays with a diff. one..I can also feel the fuel pump relay pick up like it should and drop out about 2 sec after key to off. I checked for spark...good. and changed the spark plugs because they were overdue. I just changed the fuel pump assy/fuel sending unit. Gas gage works now. still does not start. How do I check the oil pressure sensor, the camshaft pos. sensor and which would cause the fuel pump to not start at all. I have also read about an oil pressure bypass connector in the corner of the engine compartment. I can't find it to jump from the battery to that connector. Any further help would be appreciated. One more thing I did change the connector plug at the fuel pump. For reference. the old fuel pump resistance was < 1 ohm....the new one was 28 ohms. Any suggestions?
__________________
john
99 blazer
previous cars:
84 camaro berlinetta
84 camaro z28 t-tops
  #2  
Old 01-19-2009, 10:03 PM
swartlkk's Avatar
Administrator
2009 GMC Yukon Denali
My Garage
 
Join Date: May 2005
Location: Waterloo, NY
Posts: 36,947
swartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond repute
Send a message via ICQ to swartlkk Send a message via AIM to swartlkk
Default RE: 99 blazer wont start/ fuel pump not running

Start with verifying the fuel pressure with a gauge. No need to look at any other further than that. On the newer trucks, there is no interaction between the oil pressure sending unit and the fuel pump.

Does the new pump run when the key is turned on?
  #3  
Old 01-19-2009, 10:46 PM
 
Join Date: Jan 2009
Location:
Posts: 8
allenax78 is an unknown quantity at this point
Send a message via Yahoo to allenax78
Default RE: 99 blazer won't start/ fuel pump not running

A couple of more things.....I did change out the fuel filter as well. As a note when i went to bleed off pressure first, there was no pressure at the fuel rack gage connection or at either side of the fuel filter. The fuel filter was significantly harder to blow through than the new one...so it was due. I tried this before replacing the fuel pump...The lack of pressure along with no audible sound from fuel pump and no indication of relay problelms led to my decision to replace the fuel pump.
__________________
john
99 blazer
previous cars:
84 camaro berlinetta
84 camaro z28 t-tops
  #4  
Old 01-19-2009, 10:48 PM
swartlkk's Avatar
Administrator
2009 GMC Yukon Denali
My Garage
 
Join Date: May 2005
Location: Waterloo, NY
Posts: 36,947
swartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond repute
Send a message via ICQ to swartlkk Send a message via AIM to swartlkk
Default RE: 99 blazer won't start/ fuel pump not running

Did you miss my post above?
  #5  
Old 01-19-2009, 10:49 PM
 
Join Date: Jan 2009
Location:
Posts: 8
allenax78 is an unknown quantity at this point
Send a message via Yahoo to allenax78
Default RE: 99 blazer won't start/ fuel pump not running

The fuel pump doesn't turn on and there is no pressure to bleed off at the gage connection after trying to start the blazer.
__________________
john
99 blazer
previous cars:
84 camaro berlinetta
84 camaro z28 t-tops
  #6  
Old 01-19-2009, 10:55 PM
swartlkk's Avatar
Administrator
2009 GMC Yukon Denali
My Garage
 
Join Date: May 2005
Location: Waterloo, NY
Posts: 36,947
swartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond repute
Send a message via ICQ to swartlkk Send a message via AIM to swartlkk
Default RE: 99 blazer wont start/ fuel pump not running

Then have you verified power to the pump?

Also, what brand of pump did you install?
  #7  
Old 01-19-2009, 11:23 PM
 
Join Date: Jan 2009
Location:
Posts: 8
allenax78 is an unknown quantity at this point
Send a message via Yahoo to allenax78
Default RE: 99 blazer wont start/ fuel pump not running

its an airtex bought from advance......I was only getting 6 volts with the old connector when trying to start the car....while voltage to sending unit was 11. something. i didn't have small enough leads yet to check the new connector ....should have different leads tomorrow. I barely have the tank brackets in place with the bolts just started by hand so i can still check tomorrow. I wasn't getting any volts when the key was just in on. Not sure if I should have gotten voltage as the pump picks up to build up pressure in preperation to start. thanks for the quick replies by the way...i still had the screen up....without refreshing the page i didn't see your response...sorry
__________________
john
99 blazer
previous cars:
84 camaro berlinetta
84 camaro z28 t-tops
  #8  
Old 01-20-2009, 11:58 PM
 
Join Date: Jan 2009
Location:
Posts: 8
allenax78 is an unknown quantity at this point
Send a message via Yahoo to allenax78
Default RE: 99 blazer wont start/ fuel pump not running

I checked the voltage at the fuel pump. With the key on, i have 0 volts. While trying to crank it it goes to 0.3 volts. when you stop cranking it stays at 0.3 volts for a couple of seconds until the relay times out. You can hear the relay click and the voltage goes back to zero. I'm seeing 5 volts across the terminals for the sending unit. I have already swapped the relay earlier.....any suggestions? I'm gonna check to see if the lines are grounded going to the pump. Would any of the sensors (crank shaft or cam) going bad cause the drop in voltage?
__________________
john
99 blazer
previous cars:
84 camaro berlinetta
84 camaro z28 t-tops
  #9  
Old 01-21-2009, 12:52 AM
 
Join Date: Jan 2009
Location:
Posts: 8
allenax78 is an unknown quantity at this point
Send a message via Yahoo to allenax78
Default RE: 99 blazer wont start/ fuel pump not running

another question....where do you hook up a code reader on this year? and is it the standard connection type for recent code readers....or is it predated the standardized hook up.?...thanks btw...this has been my first thread here........and just browsing i've had almost every common issue that most blazer owners have endured...thanks for all the help guys.
__________________
john
99 blazer
previous cars:
84 camaro berlinetta
84 camaro z28 t-tops
  #10  
Old 01-21-2009, 07:06 AM
swartlkk's Avatar
Administrator
2009 GMC Yukon Denali
My Garage
 
Join Date: May 2005
Location: Waterloo, NY
Posts: 36,947
swartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond reputeswartlkk has a reputation beyond repute
Send a message via ICQ to swartlkk Send a message via AIM to swartlkk
Default RE: 99 blazer wont start/ fuel pump not running

You have a wiring problem as you are getting some voltage, but not the proper amount. Check the voltage at the relay.

Here is the wiring schematic:

Fuel pump connector view (original connector):


You want to test for the proper voltage at the terminal that corresponds with Pin 30 on the relay. This terminal should be hot at all times and is supplied with battery voltage through the ECM B fuse (20A). If you have +12V at this terminal, I would run a continuity test and measure the resistance between the terminal corresponding with pin 87 and pin B in the fuel pump connector. Also do a continuity test to ground with the relay removed. It should test open to ground (no continuity).
Old 01-21-2009, 07:06 AM
 
 
 
Closed Thread

Tags
96, blazer, click, fuel, oil, pump, relay, removed, run, s10, sending, start, turn, unit, volts


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Advertising

Featured Sponsors
Vendor Directory
Our Sponsors

All times are GMT -5. The time now is 11:51 AM.

Internet Brands, Inc.