So I have a 1998 blazer..No check engine light.. I cannot find anything remotely close to the issues I am having. Loss of power on occasion. Not all the time. But too frequently. Parts I have replaced include. (Fuel pump, fuel filter, coil, 02 sensors) so when I am driving it will randomly lose power. And not come back until I turn it off and restart it. Which even then the problem will happen again in a short amount of time. Things I have noticed about this problem is lack of power, cuts completely out to the point of dying when you fully press the accelerator, back firing in the intake. Have done a fuel test. Came out good. Started unplugging sensors to see if I could find one that was maybe faulty but not throwing a code. (MAF no change in idle. TPS no change in idle). Also done a cat test. Nothing. Just kinda at a loss.

 

When you say loss of power do you mean won’t accelerate but still runs or the engine stops? What is happening to system voltage and dash lights/gauges?

Did you verify fuel pressure with the test in the sticky? What brand of fuel pump did you use?

Backfiring can be a timing issue. First verify the ignition wire order. Then you should check CMP retard and adjust it to spec with a capable scanner. We can help with cost effective scanning capability. This scanner will also be able to test your sensors.

How did you test the cat? Do you mean for back pressure or efficiency? A back pressure test would be best in this case.

There is more but let’s start here.


George