1997 Chevy k1500

[Obs89]

Yup, that's what misfire smells like.

If it goes on long enough, it'll melt the catalytic converter.

"I" would connect the scan tool, and find out which cylinders are misfiring based on the misfire counts per cylinder.

All but 6 and 4 I believe I will dbl check though. Starting to think it’s the cap making a arc, even though it’s only 4 months old.I also do not have a catalytic converter nor do I have 02 sensors I am about to hook them up here shortly soon as I get gas so I can “weld” the “bongs “ in.

 

[Obs89]

On the dash gauge? Or on the scan tool?

190 on scan tool. And on dash it is the middle mark between 100 and 210.

 

[Obs89]

WHICH sensor? What is a "sending sensor"?

The temp sensor by eye valve and the sending sensor on block by manifold or headers in my case. Look up temperature sending sensor that’s how I found it. So that’s what I call it.

 

[Obs89]

Egr valve*

 

[Obs89]

Also I pinched the return line off going back to the fuel pump to see if the the pressure raised when the fuel pump is initiated. And I didn’t see the psi rise at all. So I’m thinking a new fuel pump is a must. But definitely not the main problem. I’m no genius but if the fuel pressure is that low it would be lean not rich. But again this computer has tricked me once before on these trucks. lol

 

[Schurkey]

Look up temperature sending sensor that’s how I found it. So that’s what I call it.

More accurately, temperature sending unit for an instrument cluster temp gauge. Vehicles with just a "HOT" light would have a temperature switch.

"Sensors" are generally regarded as being for the computer, not the instrument cluster.

Also I pinched the return line off going back to the fuel pump to see if the the pressure raised when the fuel pump is initiated. And I didn’t see the psi rise at all. So I’m thinking a new fuel pump is a must.

Verify that the pump is getting proper power and ground by testing for voltage as close to the pump as practical--generally at the harness connector just before the harness goes up 'n' over the tank, and also check for voltage on the ground wire.

I'm still suspicious of the accuracy of the gauge you're using for fuel pressure.

I’m no genius but if the fuel pressure is that low it would be lean not rich. But again this computer has tricked me once before on these trucks.

Misfire causes the O2 sensor to report false "lean" signal to the computer. This puts the computer into Rich Command, trying to raise the voltage of the O2 sensor.

But you don't have an O2 sensor yet, so the computer cannot get to closed-loop operation. It's bound to run a little rich.

Find the cranking compression pressure of all eight cylinders.
Is the spark powerful enough to RELIABLY fire across the gap of a spark tester calibrated for HEI?
Any chance the spark plugs have fouled?

 

[Obs89]

Verify that the pump is getting proper power and ground by testing for voltage as close to the pump as practical--generally at the harness connector just before the harness goes up 'n' over the tank, and also check for voltage on the ground wire.

I'm still suspicious of the accuracy of the gauge you're using for fuel pressure.

Everything checks out as it should . Fuel trims are as stated earlier. I will attach an picture.

But you don't have an O2 sensor yet, so the computer cannot get to closed-loop operation. It's bound to run a little rich.

Find the cranking compression pressure of all eight cylinders.
Is the spark powerful enough to RELIABLY fire across the gap of a spark tester calibrated for HEI?
Any chance the spark plugs have fouled?

dumb qustion if the truck has been programmed to read .498 volts at 02.( I do not have any) wouldn’t it be in a closed loop sense they programmed that. Also I just changed them 3 months ago and have checked the ones with misfires and just smell really gassy. Don’t look fouled to bad. It has blue/white spark so would that mean that the plug and wire is good? Or maybe it’s looks strong but not strong enough when gas makes it moist. Had same problem on. (My fourwheeler and it turned out the spark looked good but if u touched it it wasn’t strong and it was the computer.) I checked the injector test one more time starts at 50 but leaks down slowly before I can even pulse the injector. Could my problem be leaky injectors and a bad fuel pump. Cause it is smoking crazy. The tricky thing is it used to do this but stopped when I unplugged maf

 

[Obs89]

You must be registered for see images attach

 

[Erik the Awful]

if the truck has been programmed to read .498 volts at 02.( I do not have any) wouldn’t it be in a closed loop sense they programmed that.

The O2 sensor is "not programmed to read". The voltage is the voltage made by the chemical reaction in the O2 sensor, the ECM simply reads that to see if the air/fuel mixture is correct.

 

[Obs89]

The O2 sensor is "not programmed to read". The voltage is the voltage made by the chemical reaction in the O2 sensor, the ECM simply reads that to see if the air/fuel mixture is correct.

I understand but my truck is saying it has 02 sensors and reading them when they do not exist