Engine trouble

[JohnSullivan]

My 2000 sunseter lxi seems to be over fueling when first started and warmed up. It seems like I may have a sensor issue as the problem is inconsistent. Has anyone seen this? 
it is EFI

[JohnSullivan]

it looks like there are 3 temp sensors? and the one looks to be damaged (rh side front of the block) would a faulty sensor cause over fueling?

[Steve B.]

Normally no I dont think it should affect over fueling. And as I recall you should have two sensors. One feeds the ECM, and one feeds the dash gauge. Do you have an alarm going off all the time? Is your temp gauge on the dash working? Yes you should change the broken sensor either way.

When you say over fueling, give us some more details on that. Have you done complete tune ups recently?

Steve B.

 

[justgary]

8 minutes ago, JohnSullivan said:

it looks like there are 3 temp sensors? and the one looks to be damaged (rh side front of the block) would a faulty sensor cause over fueling?

Absolutely.  The engine runs open loop, and temperature is one of the input variables to the fuel table.  Change the sensor and it should be ok.

[JohnSullivan]

7 hours ago, Steve B. said:

Normally no I dont think it should affect over fueling. And as I recall you should have two sensors. One feeds the ECM, and one feeds the dash gauge. Do you have an alarm going off all the time? Is your temp gauge on the dash working? Yes you should change the broken sensor either way.

When you say over fueling, give us some more details on that. Have you done complete tune ups recently?

Steve B.

 

Thanks for the info. Yes plugs wires cap and rotor fuel filters. Changed the one temp sensor on top left yesterday and no difference  then noticed loose wire on other sensor front right. Can’t tighten. pin is loose inside sensor. Will change after weekend when things open up.  This thing runs perfect most of the time but acts up sometimes when first started. Seems rich with a bit of blue smoke when troublesome 

[Steve B.]

Keep us posted if the other new sensor helps.

Steve B.

[JohnSullivan]

On 7/3/2021 at 9:00 PM, JohnSullivan said:

Thanks for the info. Yes plugs wires cap and rotor fuel filters. Changed the one temp sensor on top left yesterday and no difference  then noticed loose wire on other sensor front right. Can’t tighten. pin is loose inside sensor. Will change after weekend when things open up.  This thing runs perfect most of the time but acts up sometimes when first started. Seems rich with a bit of blue smoke when troublesome 

Issue is still with me as soon as the hot weather came back  Seems to be a temp problem but doesn’t show up on the gauge. I suspect it puts the engine into limp mode and runs real ruff at an idle   I’m not real tecky  and started a new post on this issue 

[justgary]

You probably should check the fuel pressure.  Looking for a very consistent ~42 PSI at key on, idle, and WOT.