Hello looking for some help I have an 00 blazer the check engine light is flashing code was random misfire I changed the plugs and wires and it is still flashing my exhaust is sputtering and doesn’t seem to have any power can anyone give me any advice on what type of fix this is

 

I also notice it only flashes when I go over like 25-30 mph once I go under that it just stays on

 

A flashing CEL means that you have a misfire that is bad enough to damage the catalytic converter and needs to be dealt with. Random misfires can have many different causes so some patience is required to get to the bottom of it but we can solve this if your ready for an adventure. If so:

1. Please list all of the code numbers that you are getting
2. Do you have a scanner that can read live data and plot O2 sensor graphs?
3. Do you have a fuel pressure gauge?
4. Is there a recent compression test?
5. Any recent work on the truck right before this started?

One cheap and easy test that can help eliminate a clogged converter causing excessing exhaust back pressure is to remove an O2 senor and see if it runs any better under acceleration.

I'll stick with you as long as your up for it.

George

 

thanks for the response I don’t have a scanner mine won’t work on my blazer for some reason but I did go to autozone and they scanned it and all that came up was random misfire I changed the plugs and wires and still same code is coming up I’ll disconnect the o2 sensors and see if that works no recent work on the truck and no compression test the exhaust does sound like it’s clogged and is sputtering

 

If your going to get to the bottom of this issue you are going to need scanning capability with live data and graphing. We have some cost effective options here.

Remove an O2 sensor, not disconnect. Its going to be loud. The idea is to see of that relieves any restrictive back pressure. The best way to test this is a pressure gauge in the O2 port after the sensor is removed but since most people don't have a back pressure gauge, this is a simple first order test.


George

 

So i went back to autozone after changing the wires and plugs and it’s saying fuel pressure injector regulator so i took that apart and put a new one on everything is back to where it was but now the vehicle won’t turn over
changed the battery to a new one and still won’t crank over

 

What test did Autozone perform to tell you you had a bad fuel pressure regulator?

That part is inside the upper intake manifold and requires a fair amount of disassembly. Is that what you did?

So now you have a no crank condition or it cranks (starter rotates the engine) but won’t run?


George

 

It sounds like it’s trying to start but it can’t turn it once and yes I took everything off to out that regulator on the spider injector and put it all back properly. When it turn the key it doesn’t even crank like it would it you had no gas in it or anything . Thank you so much so the quick responses I’m very grateful that you are trying to help me


autozone just scanned my truck again and it said to replace the regulator and intake gasket but I just replaced the regulator

 

Well George I guess I’m going to try and change the starter can’t see why it went back just changing that regulator but i put a screwdriver on the solenoids and it won’t crank and then I took the relay out and jumped the wires and still nothing not sure if this is the problem but I got it out which was a pain but I’m heading to get one now. Boy they put things tight five plugs were easy the last one had to unbolt the steering column and was reading for the starter would have to unbolt my transmission and jack it up but I somehow managed to slide it out god must be with me

 

"Doesn't crank" means the engine won't turn at all. In other words the most you MGHT hear from the engine compartment is a click or series of clicks.

"...like it would it you had no gas in it or anything" means the engine turns over and over (aka as "cranks") but won't start.

Depending on which of the above it is will narrow things down and help George help you.

I also wonder what scan AutoZone used that stated the regulator as the problem? What was/were the codes? There is no DTC code that states that on these trucks. Or was it the AZ employee offering his/her diagnosis?

Be careful with their advice because it is their job to sell parts, especially if a store manager did it. They get measured very closely on sales. Parts solve everything in the auto parts store world. Scan the vehicle, get the code, sell the part.