Check engine light on, runs rich, no power.

[pdooley]

Unmodified 86 Turbo T. New plugs, wires and good coilpack.
All the sudden engine light came on and exhaust got really stinky rich, accompanied by loss of power.
I'm new to these cars and not sure how to pull the codes. Do I need a code scanner?
A Buick friend loaned me a scanmaster but I don't know how to use it, don't even know if I can use it to pull the codes.
Is there a resource or FAQ somewhere to help with these issues?

 

[ES1]

Vortex Turbo Buick Performance
Yes, the SM will show codes.
A parts store might also be able to pull the codes.

 

[ES1]

Sounds like the computer went into limp mode.

The following is a post I found when researching limp mode.

Sounds like a bad o2 sensor. When they go, the computer goes into limp mode so you're not stranded but it's rich and bogs with black smoke out the tailpipe. After you change it out put in fresh plugs and change the oil.
Also reset the computer by disconnecting the orange connector by the battery.

It may not be a bad O2 so get the code.

 

[TurboBob]

is the light on or flashing?

Look for hoses popped off, cracked, or leaking. The main air piping can pop off under boost and make the car run really badly. Also, the small hoses that connect to the turbo and wastegate can go bad from the heat and cause the turbo to overboost, which can cause engine damage (so check this).

The trouble code may tell you whats up. The scanmaster should show you the code. but you can blink the code out also. With the key on, engine off connect a piece of wire or a bent paperclip between the top righthand 2 terminals of the diagnostic plug (under the radio pod)

The check engine light will blink a series of flashes that will tell you any stored codes. It blinks 12 12 12 then whatever codes are stored. It blinks the digits out separately so a 12 is one flash.....pause....two flashed.....longer pause.....

you can also try some basic troubleshooting. The ECM has some internal backup modes that can help you.

Near the battery (underhood) is an orange wire that you can unplug, this clears the ECM memory (and trouble codes). You can do this and unplug one sensor at a time and see if the car runs better, this can help diagnose MAF (Mass airflow sensor), O2 sensor, and others.

Bob

 

[hflwyo]

Possible maf sensor?

 

[pdooley]

thx for all the replies and suggestions.
i pulled the scanmaster out and hooked it up.
the screen that said "NAL" i assume means MALfunction...
the codes were 23 and 51.
23 is air temp sensor, which makes sense b/c PO didn't have one and ran a resistor.
other error is bad prom or socket.
i reseated the chip but no difference in running.
I'm gonna make sure the IAT resistor didn't come unplugged.
it's just pushed in the wiring plug. half assed, i know, something else to fix...

 

[markboss]

Disconnect the MAF, and see if the cars runs better..if it does...MAF is bad...

 

[pdooley]

even though it didn't show on the scanmaster?

i guess i'll try anyway. can't hurt.

 

[ES1]

Sounds like a problem with the chip or ECM.

 

[pdooley]

ES1- you're right.
Unplugging the MAF didn't help.
I found another chip and swapped.
Runs much better now and the 51 code is gone.

thx.

 

[turbojd]

I also just had a code 51 with my car after taking out my emissions chip when I was done with inspection, I popped in my street TT chip and I noticed the MAL on the scanmaster ( code 51) I reset the chip and still had the code 51. I took the chip back out and took a pencil eraser to very gently and cleaned it up, popped it back the socket, and Voila, no more code 51.

 

[pdooley]

my old chip looked a little cruddy. i may try cleaning it, but the replacement works for now.