2.3L ('83-'97) Smoke testing 2.3L Lima

[R3tr0grade]

Forgive me, new member. I posted this in the wrong forum earlier.

I've been battling a lean code on my truck since I bought it. Replacing the MAF and O2 sensors seemed to help last year (the code stayed off for about 8 months) but now its back with a vengeance. When I smoke test, I don't get much of anything except some smoke from the IAC vent which I assume is normal, and some smoke from the EGR (is this normal?)

I've already replaced the pcv and some vacuum hoses connected to the EVAP system. Also I had the heater control valve fail on me and the vacuum on that was shot but I just capped it. I also don't think that would cause an engine vacuum leak?

Thoughts? Thanks!

 

[rumblecloud]

Some clarification please:
What is the code#
What is the Ranger doing running-wise
What do you mean "back with a vengeance?"

All of us have had to deal with something like this, so you will get lots of help.

 

[R3tr0grade]

Sure thing. The code is p0171. The truck runs and drives well, idle is stable. Gas mileage is normal. Everything seems normal to me.

Back with a vengeance meaning that it just returned out of nowhere even though not much changed on the truck.

My code reader shows that fuel trims are like 9% for short and about 20% long. Short goes to 0% or negative if I rev it up to 2500rpm. I think fuel delivery is okay so I assumed vacuum leak but the smoke test doesn't show anything other than EGR.

I have already replaced MAF, O2s and a couple other sensors.

 

[rumblecloud]

Almost forgot...
Welcome to TRS.

MAF and O2s are the first suspects. Vacuum leak as well...
I'm not familiar with the 2.3 but I am sure someone will be along to offer assistance. Patience. It's Saturday.

Thank you for adding that info, It will help.

I've been chasing a similar issue on my 94 4.0 for months. I finally just gave up and parked it. I have other fish to fry.

 

[rumblecloud]

Have you by any chance checked for any exhaust leaks? Wouldn't take much. Cat(s) is/are ok?

 

[R3tr0grade]

To be honest I haven't, though my exhaust isn't very loud at all. Cat appears to be okay, the voltage on my after cat 02 remains around 0V at idle.

 

[rumblecloud]

Been doing some looking around - as I am sure you have as well - and the only thing I can find is the EGR, which may be the culprit. I think that's the only thing you haven't replaced

There are a few posts that that go into it at length.

I wish I could offer more specific information, but I'll keep looking.