[babie68021]

I have a 2000 Chevy Blazer we have replaced the fuel pump and the fuel relay and my the car still won't start. We hooked up the scan tool and my truck won't read it. It cranks but WILL NOT start. Any ideas?

[TxGreaseMonkey]

. Check all under hood and under dash fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-t...tml#post252145

. Clean the main ECM ground and ensure the ECM is working--does the CEL come on and go off normally?

. Perform tests, in the link below:

https://www.askmehelpdesk.com/cars-t...ml#post2123675

. Check the ignition switch for wear, pitting, or melting, if the problem persists.

[CaptainRich]

I have a 2000 Chevy Blazer we have replaced the fuel pump and the fuel relay and my the car still wont start. We hooked up the scan tool and my truck wont read it. It cranks but WILL NOT start. Any ideas?

So, you're not getting fuel prime or fuel pressure?
Are you getting spark? Or any codes at all?
Check for power on the Gray wire, at the fuel pump during cranking or when the key is turned to the RUN position (it will only have power for a few seconds).

[c3unit]

Could be your factory anti theft system - it cuts power to the pump if it doesn't like the key. To test to see if this is the case, attempt to start it once, then leave the key in the on position for a minimum of 10 minutes. If it starts, then your anti theft system is malfunctioning.

[volvokenny]

Ahhhhh... nice looking small SUV gas guzzler. We just sold our 98 black blazer a few months ago. It had a lot of power in that 4.6 engine but yikes gets about 15L/100km had to let it go due to gas prices. A very stylish SUV but sure didn't miss going to the gas pump all the time. I wish Chev would make the same style Blazer with a smaller engine I would get one!

Here are some of the troubles I came across when I had my Blazer:

At around hundred thousand km I had trouble starting it cracks but won't start the alternator was good but it seems to suck a lot of juice from the battery I ended up buying the red top Optima battery it solved the issue.
At around 150K had trouble starting again this time it was the fuel pump as these blazers are prone to fuel pump replacements it solved the problem.
The next day after replacing the fuel pump it had trouble starting again so I took it back to the mechanic the problem was a loose spark plug wire (what a joke mechanic didn't push one of the wire into the plug hard enough). I would suggest you to check your wires and as you know they are hard to get at in these Blazers!
At around 180K it had trouble starting again. This time and strangely I had to pull the shifter back and forth then it would start. It was detected the ignition switch was starting to fail and that was changed resolved the problem.

Overall we didn't feel the reliability on our Blazer anymore so we sold it before it got higher km on the Blazer. Perhaps your blazer had the minor starting problems as I did that will have yours started again. Cheers!

[TOMZ1]

HI Thanks for the help.
I have a 2000 Chevy Blazer we have replaced the fuel pump and the fuel relay. Been checking the wiring but did't think that was it, bubby of mine thought could be security system. I do not have a chip in my key! We hooked up the scan tool and my truck won't read it. Truck starts but dies after 2 min. then fuel pump won't fire. Wait awile and pump fires truck starts . But same result. This is the 2nd replacement pump at this time. Have checked original pump & first replacment straight of battery and both fire so got think the one in now is good.

I tried your key test and it seemed to work. 2 times in a row, can I dissable security system myself. FUSE or relay. Don't see anything in fuse scamatic.

Thank.
Tom

[TxGreaseMonkey]

Tomzi, the PCM may be bad.

[TOMZ1]

could be your factory anti theft system - it cuts power to the pump if it doesn't like the key. To test to see if this is the case, attempt to start it once, then leave the key in the on position for a minimum of 10 minutes. If it starts, then your anti theft system is malfunctioning.

How can I dissable security system ?

[TOMZ1]

how can i dissable security system ?

Your test is proving to be right. 4 times now. This truck key has no chip in the key. And I have no remote @ have not added a remote starter or anything else. The car alarm horn has gone off a few times only in the past 2 years. When I open the door then if I start the truck it stops . I have had the truck for over 5 years. Can I dissable the security system myself ?

Thanks
TOMZ1

[TOMZ1]

tomzi, the PCM may be bad.

Hey how can I check this?

Thanks.
TOMZ1

[Handyman2007]

Ahhhhh...nice looking small SUV gas guzzler. We just sold our 98 black blazer a few months ago. It had a lot of power in that 4.6 engine but yikes gets about 15L/100km had to let it go due to gas prices. A very stylish SUV but sure didn't miss going to the gas pump all the time. I wish Chev would make the same style Blazer with a smaller engine I would get one!

Here are some of the troubles I came across when I had my Blazer:

At around hundred thousand km I had trouble starting it cracks but won't start the alternator was good but it seems to suck a lot of juice from the battery I ended up buying the red top Optima battery it solved the issue.
At around 150K had trouble starting again this time it was the fuel pump as these blazers are prone to fuel pump replacements it solved the problem.
The next day after replacing the fuel pump it had trouble starting again so I took it back to the mechanic the problem was a loose spark plug wire (what a joke mechanic didn't push one of the wire into the plug hard enough). I would suggest you to check your wires and as you know they are hard to get at in these Blazers!
At around 180K it had trouble starting again. This time and strangely I had to pull the shifter back and forth then it would start. It was detected the ignition switch was starting to fail and that was changed resolved the problem.

Overall we didn't feel the reliability on our Blazer anymore so we sold it before it got higher km on the Blazer. Perhaps your blazer had the minor starting problems as I did that will have yours started again. Cheers!

I know this is an older question but I have to tell you... These little 4.6 ltr engines WILL start with one spark plug wire loose. They will start with 2 wires completely off. Your mechanic was pulling your chain. He made a mistake somewhere and was just covering his a@@.
The bad battery was a no brainer. Every one of your starting problems was due to the bad park,ignition switch going bad. I bet you have a lot of keys on your key ring. Certain death for ignition switch assemblies---too much weight. 15 mpg?? Get your foot out of it. I have a 1999 and I get anywhere from 16 mpg to 24 over the road.

[rogersjames212]

My Blazer was running very well since I brought it, I just parked it at Burger King, to get something to eat, and when I tryied to start it, It wouldn't start. And I just had a new fuel pump out on a year or song ago... James

[TxGreaseMonkey]

rogersjames212, if the starter motor doesn't crank, perform an Ignition By-pass Test, by placing the transmission in Park, engaging the parking brake, removing the push-on connector from the solenoid “S” terminal, and connecting a jumper lead (12 AWG), or preferably a remote starter switch, between the B+ terminal on the solenoid (or positive battery terminal) and the exposed “S” terminal on the solenoid. If the starter motor now operates, the solenoid is fine and the problem is with the starter relay, ignition switch, neutral safety switch or clutch interlock switch, fuse, fusible link, security system, or wiring. If the starter motor still does not operate, replace the solenoid.

If it cranks but won't start, consider replacing the Ignition Control Module (ICM), especially if you have 125,000 miles or 10 years on the vehicle. First, however, check for codes, use a multimeter or test light to test all under hood and under dash fuses, and verify that you can hear the fuel pump run when the ignition switch is turned to ON.