2000 S10 2.2l Question

Sharps40

Old Mossy Horns
hard start, runs ruff, no power, can't be driven. Came on sudden.

140000 miles. new plugs, wires, coils, fuel pump fuel filter all in the last 2000 miles.

Went from running fine at 19.5 mpg. to shuddering under light load to start sputter clatter die. Chokes and coughs and backfires through the intake when reved in park.

MAP sensor checks out, good ground, 5.2v supply and signal of 4.7v and decreases to 1.2v with increased rpm.

Disconnecting Mass air flow sensor when running makes no change in idle quality or response.

Codes are front and rear o2 sensor bad and evaporative canister (these codes have been lit up for 5000+ miles of good running)

Good strong flow of exhaust out the tail pipe but rather rich smell of gas when reving the motor.

Have not yet pulled the plugs or looked into the valve body to see if its coked up.

Throttle position sensor?

Idle air control?

Is there and egr on this beast? I havn't found anything that looks like one on or near the intake or exhaust.
 

Sharps40

Old Mossy Horns
Good call .... forgot about that. Had to change them on both my blazers. I wish i could put on a carb and hei though......life was a bit simpler then. I didn't have to learn how to back probe sensors and make sure my dayum multimeter was on dc instead of ohms......
 

tarheelshooter

Twelve Pointer
Contributor
What exactly are the O2 codes ?
What is your fuel pressure?
Without looking at it I can’t be certain but pretty sure that truck had a MAP sensor but did not have a mass airflow sensor. Not quite sure what you unplugged,if it was in the intake tube it was probably the intake air temperature sensor.
 

Sharps40

Old Mossy Horns
Yep intake tube. Thought it was maf. Will have to open it up to see. Dont have fp gauge. Will ckeck o2 codes. I wrote them down.
 

Castle Oak 2

Six Pointer
Sharps, I had a bad catalytic converter that caused some of the issues you are having. My issues were progressive rather than immediate though. Also had an S-10 but was an earlier model than yours. It had a fuel/air mix heater between the carb and the intake manifold. It shorted out and caused some of the same issues you are having.
 

bigten

Old Mossy Horns
Contributor
There are several things that can cause your problems. First thing I would do is run a data scan to see what is doing what. Could be as simple as a temp sensor, but no real way to know without a scan.
 

45/70 hunter

Old Mossy Horns
Contributor
Smack the cat convertor and see if it rattles. GM had some bad cats in the early 2000's that would break loose and partially block the exhaust causing severe power loss.
 

DuckyDave

Eight Pointer
Contributor
I had 1995 S10, owned it 22 years, 170k miles when I sold it. Great truck, should have kept it, pretty sure I never replaced an EGR Valve on it although your year 2000 DOES have an EGR.
 

Sharps40

Old Mossy Horns
So far looks like 2000 has no egr. There is a factory block off plate on the back of the head. I cleaned the iac yesterday and put it back in, idled a bit better but stumbled on transition. So, I stuck my finger in the bottom of the iac hole on transitioning from idle to run by moving the butterfly.....ran a lot better/no stumble without the giant vacuum leak! There is an IAC inbound. Perhaps I'll be lucky enough that is the problem.
 
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