Two issues: Temp gauge and stumbling, hesitation

[rumblecloud]

IT takes about a mile and a half for the gauge to start registering and moving up to the first indicator mark and moves past it a little - and it stays there. I get heat. It runs fine, accelerates strong, passing gear is good. Soon after, the CEL comes on. After the CEL, I get hesitation and stumbling when accelerating. That lasts for about three or four minutes and then it runs fine again. I pulled two codes: 157 and 176 The price for the MAF is reasonable, so I'm not at all against throwing that part at it considering what I've already gone through

Guess I'm just more curious about the relationship between the temp gauge and the hesitation. It doesn't seem normal for the gauge to not get up closer to Normal.
Thanks.
R

 

[rusty ol ranger]

If you got a Tstat stuck open you might not be getting up to temp, which would mean the ECM is feeding it fuel cause it thinks the motor is still cold.

 

[rumblecloud]

I've been wondering about the thermostat. Shoulda put one in when I had the engine all torn apart. Regardless if that's the issue or not, it needs to be replaced. Thanks for the info.

 

[rusty ol ranger]

I've been wondering about the thermostat. Shoulda put one in when I had the engine all torn apart. Regardless if that's the issue or not, it needs to be replaced. Thanks for the info.

If its not the thermostat then its a gauge/sender issue.

 

[Aviator Guy]

Did you check continuity on the wire from the sensor may be is broken at some point just my 2 cents

 

[rusty ol ranger]

Did you check continuity on the wire from the sensor may be is broken at some point just my 2 cents

If the wire was broken itd not read at all. Im not sure what year the truck is, so i dont know if its got a coolant sensor for the ecm and a septrate sender for the gauge, or if its both togther.

 

[rumblecloud]

It's a 94 Splash 4.0L 4x4 -- guess I need to make it more prominent in my sig (just bein' a dick ). I'm replacing the Thermostat today and will go from there. It's cold and raining - can't think of a better way to spend my Sunday.

I think I'll update my eyeball too...
Thanks.
r

 

[rumblecloud]

Okay Replaced the thermostat, topped up the fluid and cleared the codes. Went for a nice long ride. Temp gauge acted more normal this time, getting up in the NORMAL range. Still have some hesitation and stumbling, but different this time. Before when it was having it's hissy fit if I accelerated, it wouldn't respond - just choked up. This time when I accelerated it responded well - didn't choke up.

I pulled the codes and got opposing viewpoints - 176 and 177.

I did add a large can of Seafoam to a 3/4 full tank - yes I know. I'm an idiot. I soiled the test. But would that make a difference? And what's up with the two opposing codes?

Thanks in advance.
r

 

[rusty ol ranger]

Thats interesting on the O2 codes. Im going to *guess* running rich has soot covered them. Probably fouled your plugs too, maybe even the EGR

 

[rumblecloud]

Got it. O2s are easy to get to. Plugs are easy enough. No EGR though.
Thank you.
r

 

[rumblecloud]

Update:
Rusty: Pulled and cleaned up the plugs - they weren't too bad. And am going to replace both sensors based on input from RonD

Thanks also to RonD for helping me understand what else is happening:

"176/177 are for the same driver's side O2 sensor, so yes I would guess that sensor is bad

O2 sensors use a chemical reaction to detect oxygen, and they run out of chemicals after 150k miles or 10 years whichever comes first

So yes replace BOTH O2 sensors, your MPG will also go up after you do
So they pay for themselves over the next 150k miles or 10 years."

Will update again when O2 are replaced. Thanks again all.

 

[rumblecloud]

Alrighty then...it's been a couple of weeks. Both sensors have been replaced with

BOSCH 15718

And after extensive test drives over the last few days....no codes
So I quit for awhile.
The rest of the stuff is all mechanical - yeah I know --it is until it isn't.

Now I have to figure out why my ATV won't shift.

Thank you everyone for your help. I'm not leaving, I'm just putting away my OBD1 tester and cleaning my wrenches and sharing what little knowledge I have accumulated.

r