[Chevydude2019]

I got a 1989 s10 4.3 with auto transmission. So where do we start? I was driving home came to a stoplight and it tried to die on me but i did the 2 foot method to keep it running. Well made it home and as soon as I pulled in it shut down and would not fire back up. I could pour fuel down its trought and still nothing. Next day fired up ran good then about 10 minutes later trying to die. So i parked it and replaced knock sensor.. idel control valve.. throttle sensor. rebuilt the throttle body with new fuel pressure regulator spring. And a new main computer box. After all that still has a low idle and stills try to die somtimes. And also wires plugs cap all that good stuff to and new fuel filter. So what could i be missing

 

[Chevydude2019]

Also it has a slight miss at idle. But when you're driving down the road it runs great just when at idle at a stop light

 

[Rhotpursuit]

Any codes?

 

[Chevydude2019]

No codes

 

[Chevydude2019]

And the only reason I replaced the main computer box was a friend of mine bought one for his truck and never installed it before he sold it. So i figured its worth a shot

 

[Rhotpursuit]

Not sure if the earlier years play nice with an ecm that's not vin matched. Probably too crude back hen to make a difference.

 

[Chevydude2019]

Yea i just popped it in to see if would make any difference my brother has a computer thing ( i don't want it is called) that reprogrammed when you put a box in. And it didn't change a thing. And he ran my truck for codes and all clean. The only thing his computer said was it was running a little rich.

 

[Frank Bukowski]

1. If it's running a bit rich , that's most likely a oxygen sensor .

 

[Frank Bukowski]

1. If it's running a bit rich , that's most likely a oxygen sensor .

You can also take a look at the temp sensor .

 

[Chevydude2019]

Changed both of them as well. That's actually the first thing i changed was the the o2 sensor and then the temp sensor

 

[Chevydude2019]

1. If it's running a bit rich , that's most likely a oxygen sensor .

Changed it already that was the first thing i did

 

[Chevydude2019]

You can also take a look at the temp sensor .

Have also replaced it too

 

[TerribleHobart]

Just went through the same thing on my 89. My problem was the fuel pump. You should check your pressure, it should be at 12 PSI. Mine was at 4.

 

[Chevydude2019]

Just went through the same thing on my 89. My problem was the fuel pump. You should check your pressure, it should be at 12 PSI. Mine was at 4.

I checked it last weekend when i replaced the fuel filter and it was at 12. I thought the same thing fuel pump going bad but it was holding at 12. Its a great truck had it for 8 years and first real problem ever had so can't complain to much.