Blazer cranks but won’t start. Tried several things already!
Thread Starter
CF Beginner
Joined: Jan 2019
Posts: 4
Likes: 0
From: Canada
Blazer cranks but won’t start. Tried several things already!
Hey guys and gals..
i picked up a 2005 blazer (4.3L vortec) this summer. It would sputter under load when driving. Then one night I was driving on the highway and it lost all power.. barely made it home (we’re talking 5-10km and no power!)
it sat parked for 4 months until yesterday. I tried to start it. It cranked and cranked but didn’t start.. **if I help the gas pedal to the floor it would try to start.. chugging at 300-600 rpm for a few seconds then died..** I tried pouring a bit of gas in the throttle body, which did absolutely nothing.
I’m a heavy duty mechanic, I figured I could beat this issue but I’m really stumped here and starting to feel stupid for just throwing parts at it.
So so here is what I’ve done today.
-Replaced fuel filter
-hooked up fuel pressure gauge. Showing 55psi when I turn the key and the fuel pump kicks in. It hold that pressure for 10+ minutes when I shut key off.
-replaced plugs, wires, distributor cap and rotor (they were due for change/carboned up)
-I checked timing by pulling #1 plug ang grounding it to the engine block, turned engine by hand until harmonic balancer mark lined up with the notch and saw spark on the plug., and confirmed that by pulling the distributor cap off and making sure the point was at the “6” mark which, from my research indicates cylinder 1 TDC on the distributor..
-changed crankshaft position sensor, and checked for power at the plug.
-checked ignition module plug for power
**apparenty the module was replaced before I bought it, but I can’t confirm that, it does “look new”**
- replaced MAF sensor, as there was codes for that when I first bought it and I thought maybe that’s what caused the first power loss issue when it was still running.
The reason the fella was selling it was because t would not start. He towed it to a shop and they “changed ignition module” and still no luck. So he towed it home. when I went to look at it to buy it.. I plugged in the ignition module and t fired right up! It ran decent for a few months but then the situation as I destabove happened and now it’s not starting.
(Those butt holes at the repair shop left the ignition module unplugged when they changed it!!!)
if anybody has any info I would really appreciate it!
i picked up a 2005 blazer (4.3L vortec) this summer. It would sputter under load when driving. Then one night I was driving on the highway and it lost all power.. barely made it home (we’re talking 5-10km and no power!)
it sat parked for 4 months until yesterday. I tried to start it. It cranked and cranked but didn’t start.. **if I help the gas pedal to the floor it would try to start.. chugging at 300-600 rpm for a few seconds then died..** I tried pouring a bit of gas in the throttle body, which did absolutely nothing.
I’m a heavy duty mechanic, I figured I could beat this issue but I’m really stumped here and starting to feel stupid for just throwing parts at it.
So so here is what I’ve done today.
-Replaced fuel filter
-hooked up fuel pressure gauge. Showing 55psi when I turn the key and the fuel pump kicks in. It hold that pressure for 10+ minutes when I shut key off.
-replaced plugs, wires, distributor cap and rotor (they were due for change/carboned up)
-I checked timing by pulling #1 plug ang grounding it to the engine block, turned engine by hand until harmonic balancer mark lined up with the notch and saw spark on the plug., and confirmed that by pulling the distributor cap off and making sure the point was at the “6” mark which, from my research indicates cylinder 1 TDC on the distributor..
-changed crankshaft position sensor, and checked for power at the plug.
-checked ignition module plug for power
**apparenty the module was replaced before I bought it, but I can’t confirm that, it does “look new”**
- replaced MAF sensor, as there was codes for that when I first bought it and I thought maybe that’s what caused the first power loss issue when it was still running.
The reason the fella was selling it was because t would not start. He towed it to a shop and they “changed ignition module” and still no luck. So he towed it home. when I went to look at it to buy it.. I plugged in the ignition module and t fired right up! It ran decent for a few months but then the situation as I destabove happened and now it’s not starting.
(Those butt holes at the repair shop left the ignition module unplugged when they changed it!!!)
if anybody has any info I would really appreciate it!
CF Active Member
Joined: Dec 2018
Posts: 163
Likes: 8
From: Virginia
Don't overlook the basics. When was the last tune up? How old are the spark plugs? Might want to check them and replace if their age is unknown. Read a thread on another forum where the vehicle died and the owner could not get it to start. It would crank all day and fuel pump, various sensors confirmed to be good. Pulled the plugs and found them severely worn. Put new plugs in and behold it started.
Thread Starter
CF Beginner
Joined: Jan 2019
Posts: 4
Likes: 0
From: Canada
Don't overlook the basics. When was the last tune up? How old are the spark plugs? Might want to check them and replace if their age is unknown. Read a thread on another forum where the vehicle died and the owner could not get it to start. It would crank all day and fuel pump, various sensors confirmed to be good. Pulled the plugs and found them severely worn. Put new plugs in and behold it started.
i changed the plugs and wires about 5 months ago, right after it let me down the first time. It started and ran after I changed them, but still had no power (would only drive 5km per hour) and sputter. But after sitting for a while it won’t even start now..
im considering emptying fuel tank and putting fresh fuel in it, after that I’m going to do more fuel system testing, I guess. I’m really hoping I don’t have to start messing around with the fuel injectors.
CF Active Member
Joined: Feb 2018
Posts: 185
Likes: 1
From: Currently the Candian Gander is wintering over in New York.
Maybe a vacuum leak.
Maybe a timing chain that has jumped time.
Maybe a cam sensor not getting a switching signal because the magnet (if any) has fallen off the cam gear. You can pull the sensor, and look into the hole with a flashlight , rotate the engine, and verify the magnet is still in place.
I found this https://www.autozone.com/repairguide...96b43f81b3c3d9 which gives some good generic testing information.
How many miles are on the odometer?
Maybe someone sugared the gas tank. I think there are chemical tests available to check for this.
Maybe a timing chain that has jumped time.
Maybe a cam sensor not getting a switching signal because the magnet (if any) has fallen off the cam gear. You can pull the sensor, and look into the hole with a flashlight , rotate the engine, and verify the magnet is still in place.
I found this https://www.autozone.com/repairguide...96b43f81b3c3d9 which gives some good generic testing information.
How many miles are on the odometer?
Maybe someone sugared the gas tank. I think there are chemical tests available to check for this.
Last edited by Kazoocruiser; Jan 24, 2019 at 12:21 AM.
Thread Starter
CF Beginner
Joined: Jan 2019
Posts: 4
Likes: 0
From: Canada
Maybe a vacuum leak.
Maybe a timing chain that has jumped time.
Maybe a cam sensor not getting a switching signal because the magnet (if any) has fallen off the cam gear. You can pull the sensor, and look into the hole with a flashlight , rotate the engine, and verify the magnet is still in place.
I found this https://www.autozone.com/repairguide...96b43f81b3c3d9 which gives some good generic testing information.
How many miles are on the odometer?
Maybe someone sugared the gas tank. I think there are chemical tests available to check for this.
Maybe a timing chain that has jumped time.
Maybe a cam sensor not getting a switching signal because the magnet (if any) has fallen off the cam gear. You can pull the sensor, and look into the hole with a flashlight , rotate the engine, and verify the magnet is still in place.
I found this https://www.autozone.com/repairguide...96b43f81b3c3d9 which gives some good generic testing information.
How many miles are on the odometer?
Maybe someone sugared the gas tank. I think there are chemical tests available to check for this.
I checked the timing, as described in my original description. So I’m ruling that out as a problem.
and I don’t believe the gas has been tampered with I do think I’m going to drain the tank and put fresh fuel in it.
It has 180 km. As written in my original description
CF Active Member
Joined: Feb 2018
Posts: 185
Likes: 1
From: Currently the Candian Gander is wintering over in New York.
Hey guys and gals..
i picked up a 2005 blazer (4.3L vortec) this summer. It would sputter under load when driving. Then one night I was driving on the highway and it lost all power.. barely made it home (we’re talking 5-10km and no power!)
it sat parked for 4 months until yesterday. I tried to start it. It cranked and cranked but didn’t start.. **if I help the gas pedal to the floor it would try to start.. chugging at 300-600 rpm for a few seconds then died..** I tried pouring a bit of gas in the throttle body, which did absolutely nothing.
I’m a heavy duty mechanic, I figured I could beat this issue but I’m really stumped here and starting to feel stupid for just throwing parts at it.
So so here is what I’ve done today.
-Replaced fuel filter
-hooked up fuel pressure gauge. Showing 55psi when I turn the key and the fuel pump kicks in. It hold that pressure for 10+ minutes when I shut key off.
-replaced plugs, wires, distributor cap and rotor (they were due for change/carboned up)
-I checked timing by pulling #1 plug ang grounding it to the engine block, turned engine by hand until harmonic balancer mark lined up with the notch and saw spark on the plug., and confirmed that by pulling the distributor cap off and making sure the point was at the “6” mark which, from my research indicates cylinder 1 TDC on the distributor..
-changed crankshaft position sensor, and checked for power at the plug.
-checked ignition module plug for power
**apparenty the module was replaced before I bought it, but I can’t confirm that, it does “look new”**
- replaced MAF sensor, as there was codes for that when I first bought it and I thought maybe that’s what caused the first power loss issue when it was still running.
The reason the fella was selling it was because t would not start. He towed it to a shop and they “changed ignition module” and still no luck. So he towed it home. when I went to look at it to buy it.. I plugged in the ignition module and t fired right up! It ran decent for a few months but then the situation as I destabove happened and now it’s not starting.
(Those butt holes at the repair shop left the ignition module unplugged when they changed it!!!)
if anybody has any info I would really appreciate it!
i picked up a 2005 blazer (4.3L vortec) this summer. It would sputter under load when driving. Then one night I was driving on the highway and it lost all power.. barely made it home (we’re talking 5-10km and no power!)
it sat parked for 4 months until yesterday. I tried to start it. It cranked and cranked but didn’t start.. **if I help the gas pedal to the floor it would try to start.. chugging at 300-600 rpm for a few seconds then died..** I tried pouring a bit of gas in the throttle body, which did absolutely nothing.
I’m a heavy duty mechanic, I figured I could beat this issue but I’m really stumped here and starting to feel stupid for just throwing parts at it.
So so here is what I’ve done today.
-Replaced fuel filter
-hooked up fuel pressure gauge. Showing 55psi when I turn the key and the fuel pump kicks in. It hold that pressure for 10+ minutes when I shut key off.
-replaced plugs, wires, distributor cap and rotor (they were due for change/carboned up)
-I checked timing by pulling #1 plug ang grounding it to the engine block, turned engine by hand until harmonic balancer mark lined up with the notch and saw spark on the plug., and confirmed that by pulling the distributor cap off and making sure the point was at the “6” mark which, from my research indicates cylinder 1 TDC on the distributor..
-changed crankshaft position sensor, and checked for power at the plug.
-checked ignition module plug for power
**apparenty the module was replaced before I bought it, but I can’t confirm that, it does “look new”**
- replaced MAF sensor, as there was codes for that when I first bought it and I thought maybe that’s what caused the first power loss issue when it was still running.
The reason the fella was selling it was because t would not start. He towed it to a shop and they “changed ignition module” and still no luck. So he towed it home. when I went to look at it to buy it.. I plugged in the ignition module and t fired right up! It ran decent for a few months but then the situation as I destabove happened and now it’s not starting.
(Those butt holes at the repair shop left the ignition module unplugged when they changed it!!!)
if anybody has any info I would really appreciate it!
CF Active Member
Joined: Feb 2018
Posts: 185
Likes: 1
From: Currently the Candian Gander is wintering over in New York.
https://www.autoblog.com/2016/01/05/...sition-sensor/
https://www.doityourself.com/stry/3-...amshaft-sensor
https://www.openbay.com/articles/camshaft-position-sensor
https://axleaddict.com/auto-repair/Bad-Camshaft-Position-Sensor-Symptoms
Last edited by Kazoocruiser; Jan 26, 2019 at 11:01 AM. Reason: added hyperlink
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CF Beginner
Joined: Jun 2018
Posts: 7
Likes: 0
i will try pulling cam sensor when I am back in town. Though i don’t think a cam sensor would not cause a no start condition.
I checked the timing, as described in my original description. So I’m ruling that out as a problem.
and I don’t believe the gas has been tampered with I do think I’m going to drain the tank and put fresh fuel in it.
It has 180 km. As written in my original description
Usual crankshaft sensor problems
Did you try reading the codes?
Crank shaft related problems usually cause no-spark and no-fuel-injector-pulse.
Have you ever used an engine start spray? If you are familiar with this, you can try it to see if it will give any signs of life.
Hope it helps.