1990 m30 guzzling gas

[rubenzbeau]

11/89 build 535/5
engine code reads 1222

Since ive owned the car ive replaced the following

fuel injectors
spark plugs
spark plug wires
fuel filter
distro cap
distro rotor

and still it heavily smells of fuel what could i be missing? the only known problem with the car is that the speed sensor needs replacement (speedometer, odometoer and avg mpg dont work ) would this cause it to run rich. i will get to that soon just so i know how fast i am going. can it just an an 02 sensor? runs fine so i didnt suspect any vacuum leaks. Also exhaust is a very light milky white (obviously)
Any help would be appreciated. Please and thank you.

engne

[3axap]

1222 is the O2 sensor code. If you ruled out fuel delivery and spark issues, that would be the next item on the replacement list. Vacuum leaks typically don't result in excessive fuel consumption.

[SinisterMoose]

You didn't mention fuel pressure regulator, that would make it run rich, and it will contaminate the oil with fuel.

A rich condition that the DME can't compensate for, may cause an o2 sensor code as well.

A quick and dirty test is to pull the vacuum line off the fuel pressure regulator and see if the vacuum line smells strongly of fuel, or if a lot of fuel is evident

Also, a strong smell of fuel could indicate that one of the fuel lines (the rubber part) has split or is leaking, which wouldn't affect the running (too much), especially if it's on the return line.

[rubenzbeau]

1222 is the O2 sensor code. If you ruled out fuel delivery and spark issues, that would be the next item on the replacement list. Vacuum leaks typically don't result in excessive fuel consumption.

definitely i just thought i read somethin about the vac lines triggering that code.

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You didn't mention fuel pressure regulator, that would make it run rich, and it will contaminate the oil with fuel.

A rich condition that the DME can't compensate for, may cause an o2 sensor code as well.

A quick and dirty test is to pull the vacuum line off the fuel pressure regulator and see if the vacuum line smells strongly of fuel, or if a lot of fuel is evident

Also, a strong smell of fuel could indicate that one of the fuel lines (the rubber part) has split or is leaking, which wouldn't affect the running (too much), especially if it's on the return line.


i forgot to mention that the fpr looks brand spankin new so i assumed it was replaced before my purchase but it could be faulty. ill try swapping it with the one from my other car . but i wouldnt count on using the other parts for testing on the other car. i will try the fpr this weekend. thank you all for the advice!!!

[SinisterMoose]

i forgot to mention that the fpr looks brand spankin new so i assumed it was replaced before my purchase but it could be faulty. ill try swapping it with the one from my other car . but i wouldnt count on using the other parts for testing on the other car. i will try the fpr this weekend. thank you all for the advice!!!

The o2 sensor could be completely dead, which, may affect the economy gauge and if I'm not mistaken the DME will default to "Open Loop" mode, which throws "extra" fuel to the engine, like the engine is cold all the time. The economy gauge gets input from two or three places I think, the o2 sensor is one that I know of, and possibly the tach, and speed sensor, and it could also be using vacuum or throttle angle or some other mysterious data thrown at it to calculate economy.

I have actually ripped the o2 sensor wire connector loose (accidentally driving over a chunk of tire on the interstate), and the car ran like a pig afterwards. It might be worth checking the connectors to the speed sensor, and the o2 sensor. The o2 sensor wire is like 5 or 6 feet long. The connector on mine was beside the block under the intake.

[ross1]

Is the cyl ident wire from the #6 spark plug lead connected?

[Binjammin]

O2 sensor codes are pretty generic on almost every BMW ever made, and in reality it's almost always the fault of something further upstream. You can monitor the voltage of the O2 sensor to see if it's switching rich/lean etc... but I'd suspect something like a cracked intake boot before an O2 sensor had failed. Not to say it's impossible for one to fail, by any stretch, but just do your due diligence before you make an assumption and throw parts at the problem.

[3axap]

Be sure to check all of the vacuum lines that are attached underneath the manifold and also take a look at the check valve located close the brake booster. That sucker often has an extra barb on it that should be capped off. If the barb is broken off, you may have a vacuum leak there.

[rubenzbeau]

Is the cyl ident wire from the #6 spark plug lead connected?

i will look that over tonight. thanks ross

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The o2 sensor could be completely dead, which, may affect the economy gauge and if I'm not mistaken the DME will default to "Open Loop" mode, which throws "extra" fuel to the engine, like the engine is cold all the time. The economy gauge gets input from two or three places I think, the o2 sensor is one that I know of, and possibly the tach, and speed sensor, and it could also be using vacuum or throttle angle or some other mysterious data thrown at it to calculate economy.

I have actually ripped the o2 sensor wire connector loose (accidentally driving over a chunk of tire on the interstate), and the car ran like a pig afterwards. It might be worth checking the connectors to the speed sensor, and the o2 sensor. The o2 sensor wire is like 5 or 6 feet long. The connector on mine was beside the block under the intake.

just ordered 02 and speed sensor from rockauto. hopefully its a quick fix.

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i will also look at that thanks for the tip!

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The o2 sensor could be completely dead, which, may affect the economy gauge and if I'm not mistaken the DME will default to "Open Loop" mode, which throws "extra" fuel to the engine, like the engine is cold all the time. The economy gauge gets input from two or three places I think, the o2 sensor is one that I know of, and possibly the tach, and speed sensor, and it could also be using vacuum or throttle angle or some other mysterious data thrown at it to calculate economy.

I have actually ripped the o2 sensor wire connector loose (accidentally driving over a chunk of tire on the interstate), and the car ran like a pig afterwards. It might be worth checking the connectors to the speed sensor, and the o2 sensor. The o2 sensor wire is like 5 or 6 feet long. The connector on mine was beside the block under the intake.


my injectors were definitely fucked when i changed them out last week and the fuel smell went down a little bit and so did the milky exhaust. im hoping that the injectors just messed the o2 sensor and i dont have to do too much more.