My 1991 240 Wagon is not running - Need Help Please

I bought a 1991 240 SE Wagon Automatic Trans w/ Overdrive. It was not
turning over or starting when I bought it but I did the following -
replaced, distributor cap, plugs, fuel relay and nuetral switch. It
started right up but was running real rough and very rich. Yesterday I
moved the car in the driveway and when I went back it would not start.
It is turning over but not firing up. I have no idea what it could be.
What would suddenly keep it from firing up.

I have access to several similar cars at a salvage yard but do not know
what to get. I also need to change the Oxygen Sensor but do not know
its location. Is it the spark plug looking thing that screws into the
exhaust pipe under the car. It has wires coming off it it. If thats not
the O2 Sensor then what is it. My mechanic told me to change it. Thanks
to any and all advice.

 

The oxygen sensor only matters when the car is warmed up; a shot sensor
will not affect cold start performance.

I'd suspect fuel injection issues, starting with air mass meter.

 

Locate the Air Mass Meter in the intake hose, and carefully
disconnect the electrical connector from it. If the car starts
right up, you need a new or rebuilt or good used AMM. You
shouldn't drive it with the unit unplugged, as it will still be
way too rich. Disconnecting it just gives you a primitive 'limp
home mode'.

Did you by any chance wash the engine? 240 engine compartments
feel the same way about being washed as cats do.

 

I dont think AMM is bad because when it was running I checked it by
starting the car the disconnecting the AMM and the car changed its
idiling immediately. I was told that means the AMM is working and in
good shape. Its turning over great and occasionally starts up but then
dies right away fter sputtering then it wont start again. I have
checked all my vaccum hose and all hose connections and everything
seems to be OK.
Should I change the fuel injection plug ins?
Also I didnt wash the car but I did leave the hood open overnight. I
will pull the Distributor cap off and see if it has any moisture.
I dont know what else to check and I need to get this at least running
enough to get it to a shop. I live out in the country and a tow would
cost me a fortune. Thanks

 

Did you do all the routine stuff like adding dry gas, remove the gas
cap, changing the fuel filter, air cleaner, plugs and wires and rotor
and distributor cap? Usually only one injector will go bad and the car
should at least act like it is running on two cylinders. Also drain out
some gas and see if it looks OK. I have gotten bad gas several times.

 

Start with the basics. Clean the grounds on the intake manifold, the
battery negative to block at the block, and the static strap between the
engine and the firewall. Make sure all the hoses and tubes have no cracks
or breaks and are held or holding themselves in place with no cracks at the
ends.

Remove and clean the following connectors. AMM, throttle switch, and temp
sender for the ECU under the third intake runner.

Then clear the ECU of codes. When symptoms reappear, retrive the codes and
start from there. Sometimes the code tells you right out what is wrong.
Sometimes it takes a bit of sluething to figure out what is causing the
problem.

Don't know how to clear or obtain the codes. Get a Bentley Manual and
follow the instructions. That manual will also guide you through testing
individual components based upon the code retrived.

Duane

 

I strongly suggest that you take the car to a dealer with the proper
equipment to diagnose the problem. You appear to be using the
replace-parts-until-something-get's-better methond opf car repair.
Chances are you will spend a lot of time and money swapping out
perfectly good parts and not find the real problem.