o2 check engine light with sporatic idle and studdering

[Dodobrown]

Recently my car thew a check engine light for a o2 sensor with out any further diagnostic i replaced the sensor with a brand new one. Unfortunately this did not fix my cel and ive been killing my self ever since trying to isolate my problem.

For the past few days ive been scowering the interwebs trying to find any information on reasons for this code (1221) but nothing seems to help.

i have a 1989 325ix with:
new plugs, wires, cap, rotor
long tube headers back (no cat)
new coolant temp sensor
new thermo stat
new fuel filter

the car will drive fine some days with no signs of a problem aside from the cel other days the car will buck and sputter like i have a misfire only under acceleration then eventually run smooth at consistent throttle position. recently now that the weather has been getting warmer the car seems to be over heating (not into the red but 3/4 of the way up).

ive checked the coolant system for leaks replaced the coolant temp sensor and checked the fuel pressure regulator all seem to be fine. Checked for vacuum leaks with about a full bottle of carb cleaner and all seems ok.

any idea where i should look next. im becoming very tempeted to bring the car to some one to have it fixed but i would really like the satisfaction of fixing the car my self.

[bernzpeed]

fuel injector cleaner?
clean intake?

[KenC]

FPR is my guess. Could be a clogged fuel filter or fuel pump issue.
Check the contact sweep on your AFM too.

[Dodobrown]

i swaped my afm for another seem to be the same problem. ive never done a fuel pressure test although im considering buying the guage. i'll have to grab some injector cleaner. prob get one of those lucust half gallon ones unless any one things theres a better one out there

[ashton]

i swaped my afm for another seem to be the same problem. ive never done a fuel pressure test although im considering buying the guage. i'll have to grab some injector cleaner. prob get one of those lucust half gallon ones unless any one things theres a better one out there

My car is doin the same thing. I've got an 88 325i. It has a new fuel pump, fuel filter, o2 sensor, new afm, and more. Any ideas guys? It'll sputter and die goin down the road too. There is no check engine lights at all. So I have no clue what it could be....

[Dodobrown]

your problem sounds like a large vacuum leak. if you havent already get a can of carb cleaner with the engine running spray down any areas where theres a gasket or a vacuum line.

[ashton]

your problem sounds like a large vacuum leak. if you havent already get a can of carb cleaner with the engine running spray down any areas where theres a gasket or a vacuum line.

What about the whole on the side of my cold air intake? Should I plug it?

[Dodobrown]

im not sure what the hole is there for but id say yes. give it a try it cant hurt.

[ashton]

im not sure what the hole is there for but id say yes. give it a try it cant hurt.

Alright it didn't make a difference....

[Dodobrown]

story of this car's life lol.

[7pilot]

The check engine light flashing with the tach needle drop suggests that it is an ignition problem.
The possible culprits:
1, Ign cap and rotor.
2, The CPS.
3, The coil.
4,The DME.
5, Plug wires.

m

[Andy348]

Engine grounds look good?

[Dodobrown]

im not quite sure but i think its coolant related. its been getting very hot here on the east coast and ive always had a coolant issue. my hoses never really feel "full" you can pinch them all the way thru when the cars at temperature. and the temp fluctuates considerably. ive had a shop replace my coolant last year so i though it was all good but now im thinking that coolant isnt making proper contact with the coolant temp sensor which is causing my cel light. either way i have a new more important problem to fix

[jlevie]

If the cooling system has enough air in it to cause the ECT to read low, the engine would be overheating and the hoses would be rock hard whrn the engine is at temperature.

The common "O2 sensor fault" is 1222. Which is a Lambda fault and it could be a bad sensor but is more commonly the result of an improper A/F ratio. The most common cause of that is intake leaks and the second most common cause is a fuel system or injector problem. Other causes are possible but those have to be ruled out first. The only sure way of locating intake leaks is to have a smoke test run. The Bentley manual has fuel system tests, but you have to have the injectors flow tested.

[Dodobrown]

^ thanks for the help dude that was very to the point and straight forward. i'll have to get the car smoke tested as soon as i can afford it. as far as the injectors go i'll prob just go to some ford 19lb injectors if i still havnt found the problem after the smoke out.