I have a 03 trailblazer and it recently started with this problem my car runs fine has power but once a week the temp gauge will drop down and as soon as I shut the car off it won't start until at least 20 mins then it will run and start fine I've been told its the fuel pump but wanted another opinion before I put time money and labor into it
Thermostat drop and no start
- Thread starter Leobastille
- Start date
Mooseman
Moderator
Could be an electrical issue if your temp gauge drops like that all of a sudden. Maybe try swapping the ignition switch as a cheap and easy shotgun.
When it won't start, can you hear the fuel pump? Foes.the other stuff power on normally?
When it won't start, can you hear the fuel pump? Foes.the other stuff power on normally?
I changed the ignition switch a little while back and I can hear the fuel pump each time I try to turn it over
Mooseman
Moderator
Well the temp gauge is controlled by the PCM via the cluster logic board. Wonder if the PCM or connection is flaky given that it happens when it's warm.
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If you want to either Change your Fuel Filter and/or Test the Fuel Pressure... This link has good images to show its location and the Acces Fuel Pressure Testing Schrader Valve Port on the same Filter Unit:
@MAY03LT 's Famous "How to Test Fuel Pressure on the 02'-04' Trailblazers" provides some Good Visuals and Verbals for how to perform this Test:
Also... if you are having "Temperature Issues" that also involve problems with your Electro-Viscous Fan-Clutch acting up... be advised that it may be sharing a (5) Volt Reference Signal from the PCM with the Fuel Pump. GM uses a Class 2 Network that employs ONE SINGLE (0-7) VDC Network Wire for PWM (Pulse Width Modulation) signalling... and as such, problems with Individual Modules on the Vehicle Network can negatively impact OTHER unrelated Modules elsewhere within the Vehicle.
Using your Scan Tool and reading the History of any Trouble Codes (PXXX) can often reveal what is actually causing these problems. Your Sketchy Instrument Cluster Readings would prompt me to check for the G201/SP201Grounding Screw that Fastens all of these in commonality to the outer hard metal shell of the Transmission hump on the Passenger side of the Vehicle below the Dash Panel . In this next video... Once again... MAY03LT explains WHY this One Ground can give us all so many headaches if it is NOT properly connected to the Truck Body as a GOOD GROUND BONDING CONNECTION:
So... Welcome Back... to GMT Nation... Leo :>)
Chevy TrailBlazer fuel filter location and replacement
How to replace Chevy TrailBlazer fuel filter from the year 2003, 2004, 2005, 2006, 2007 and 2008. Locate and replace Chevrolet TrailBlazer fuel filter.
filterlocation.com
@MAY03LT 's Famous "How to Test Fuel Pressure on the 02'-04' Trailblazers" provides some Good Visuals and Verbals for how to perform this Test:
Also... if you are having "Temperature Issues" that also involve problems with your Electro-Viscous Fan-Clutch acting up... be advised that it may be sharing a (5) Volt Reference Signal from the PCM with the Fuel Pump. GM uses a Class 2 Network that employs ONE SINGLE (0-7) VDC Network Wire for PWM (Pulse Width Modulation) signalling... and as such, problems with Individual Modules on the Vehicle Network can negatively impact OTHER unrelated Modules elsewhere within the Vehicle.
Using your Scan Tool and reading the History of any Trouble Codes (PXXX) can often reveal what is actually causing these problems. Your Sketchy Instrument Cluster Readings would prompt me to check for the G201/SP201Grounding Screw that Fastens all of these in commonality to the outer hard metal shell of the Transmission hump on the Passenger side of the Vehicle below the Dash Panel . In this next video... Once again... MAY03LT explains WHY this One Ground can give us all so many headaches if it is NOT properly connected to the Truck Body as a GOOD GROUND BONDING CONNECTION:
So... Welcome Back... to GMT Nation... Leo :>)
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christo829
Member
If the low fuel light is on, then that could point to the sender. If the gauge reads empty but the fuel light stays off, that might be the gauge stepper motor itself failing. Since it doesn't sound like it displays the same intermittent behavior of the temperature gauge or the starting, it's probably not related.
A friend of mine rebuilt a jeep that ended up having a "hot, no start" problem that turned out to be a bad connector at the firewall that would move back in to contact as things cooled off. So you could still be fighting a bad connection. If the fuel pump was having a problem, you'd most likely have other driveability symptoms once things got warmed up, not just the "hot, no start". It sounds almost as if the temp gauge dropping is indicative of the circuit failure that is also causing the
"hot, no start" problem. So, you always see this pattern? There's never been a time when the temp gauge has stayed on but the truck has failed to start , or the temp gauge has failed but the truck *has* started?
Good Luck-
Chris
This is the first I'm dealing with the temp gauge itself it usually stays in the middle even after a 200 mile trip it's the first I'm seeing of this
Mooseman
Moderator
Well, maybe the gauge is working correctly and your thermostat is bad. It might be staying stuck open after it's warmed up. If it drops down to about halfway between 1/4 and 1/2 way, that could be it. Maybe after it fully cools, it closes until the next time it's hot.
However, I don't think it's related to the warm/no start you are experiencing. I did find this old thread that could help:
gmtnation.com
Edit: I also just moved this thread to the proper section as it was in the Full sized trucks.
However, I don't think it's related to the warm/no start you are experiencing. I did find this old thread that could help:
2002 trailblazer wont start once warmed up
02 TB LT 4.2 4wd 200,000+ miles starts just fine when cold but once it warms up i just get at most a pop. I get nothing if i just crank on the ignition, but if i put the gas pedal to the floor it gives the pop like it might start to start. I have to wait at least 30min and it will just start...
gmtnation.com
Edit: I also just moved this thread to the proper section as it was in the Full sized trucks.