1990 240 white & black exhaust poor MPG

rainbowwillow63 · Post by **rainbowwillow63** » 01 Oct 2009, 20:26

Here we go again-

Fixed the last problem and now when I start it it blows lots of white exhaust. After awhile it starts blowing black exhaust with LOTS of carbon buildup. It is also getting really bad gas mileage like 12-14 miles per gallon. HELP!!!!

Post by **billofdurham** » 02 Oct 2009, 12:48

Do you have a check engine light this time?

Regardless of the CEL have you checked for fault codes using the On-Board Diagnostic (OBD) unit in the engine compartment?

Without seeing the car the symptoms you describe indicate the fuel/air ratio is too rich and you may be having problems with the heated oxygen sensor. However, check for fault codes before dashing out and buying one.

Bill.

rainbowwillow63 · Post by **rainbowwillow63** » 02 Oct 2009, 15:42

Nope, no CEL. Do I need to take it to a garage to have the codes read? I figured it would be gas/air ratio but I don't know anything about fixing that.

Post by **billofdurham** » 03 Oct 2009, 15:52

Do I need to take it to a garage to have the codes read?

No, you can do it yourself with the attached instructions:

200 Tests w_codes.pdf: (3.54 MiB) Downloaded 457 times

1989 and 1990 are the same. There may be no codes stored but it is worth checking, as it is free.

You now know something that a lot of non-Volvo garages don't - how to read fault codes on a Volvo 240.

Bill.

rainbowwillow63 · Post by **rainbowwillow63** » 03 Oct 2009, 20:27

I couldn't get the file to download-it says it is damaged and cannot be fixed

Post by **billofdurham** » 04 Oct 2009, 12:41

Now how did you break that?

I have downloaded it successfully but in case you are still having trouble go to 240 tests with codes and see if you can break that one.

Bill.

rainbowwillow63 · Post by **rainbowwillow63** » 04 Oct 2009, 16:53

I guess I broke that one too

That's just how my luck has been going lately. I guess no fix for me

rainbowwillow63 · Post by **rainbowwillow63** » 06 Oct 2009, 15:05

Hey Bill- I checked for codes

, there are none stored. Anything else I need to check?
It is still running rough but not stalling since I beat the cat. up.

Post by **billofdurham** » 06 Oct 2009, 15:36

No codes - back to basics.

Check throttle switch and connector.
Check ignition and sensor wires for good connections.
Check the earth (ground) connections on the intake manifold.
Check engine speed sensor.
Check for a leak on the intake manifold.
Check engine coolant temperature sensor (ECT). There are two of these, one for the temp gauge the other feeds info to the fuel control unit. You need to check the second one which you will find under the intake manifold for #3 cylinder. Hard to get at but does cause troubles with fuel consumption/running if it goes off.

Most of these items are on the forum if you do a search. Certainly the ECT is on, search with my name as author.

If you can't find any information on any of the above post back.

Bill.

rainbowwillow63 · Post by **rainbowwillow63** » 12 Oct 2009, 10:43

Well, I finally figured out how to get the codes (duh, turn ignition on

).

Here are the codes I got:
Socket 2- 121, 113, 213

Socket 6- 111

I'm going to erase these and recheck after I drive again. Does it matter what order they are in? Again, I have no CEL.

I checked my oil today and it smells of gas??