1222 code thrown randomly

[603Racing]

I get a random 1222 code. The whole story...

'90 325i, ~180k miles on the car, ~130k on the m20.

A few weeks ago my car started to idle rough when cold and didn't run to well until driven for a minute or so. It go worse when it was near zero degrees. So, I knew it was the temp sensor.

On the way home from work (25 miles) three days ago, it started bucking a bit then missing fairly bad. To the point where my top speed was about 50mph. Then it came right out of it. The check engine light came on, then went back off. Stomp test = 1222.

An hour later I drove it for about 10 minutes with no issues. Next morning drove it 25 miles to work, no issues. Drove home after work, same random bucking, missfire. It would run bad for 3 or 4 second sometimes, other times it would run bad for a few minutes. Again, code 1222.

I replaced the temp sensor that night. Took it for a 10 minute drive, no issues. It ran fine when cold, idle well, ran good when warmed up. Yesterday morning, drove to work, no issues. Last night on the way home, same issues came back.

So now, I know it's not the sensor itself. I know the possible causes of 1222. Here are some of the variables... I filled the car up with gas last Friday, haven't put any more in it since. I'm at 1/4 tank. Issue first appeared at 3/4 tank. Plug wires are less than a year old, plugs look good. I checked all the electrical connectors at the injectors. Double checked connetor for temp sensor. FPR, fuel filter, ICV, are all about a year old. 17# injectors were cleaned and "rebuilt" and installed with MarkD chip about 9 months ago.

To do list... Test CPS, check injector harness connection, and if need be check fuel pressure. The problem with the fuel pressure test is that the issue is random. I've had fueling issues in my race car, and this does have similiar characteristics. I'm just wondering if I have a fuel pump issue, as far as I know it still has the original setup.

I know the things I need to check. Does anyone know of anything I'm not thinking of here? Any other ideas? Sorry for the long post, just wanted to get all the details in here.

[enigmaticdream]

1222 is lamda (o2 sensor)
1223 is coolant temp sensor

[enigmaticdream]

https://www.bimmerinfo.com/bmw_flash_codes.htm

[N2MYE30]

^^^I keep that list of those codes in both of my cars glovebox at all times.

[603Racing]

I'm aware of what the codes are (not to sound like an ass). 1222 does not necessarily mean the O2 sensor is bad, it simply means that the O2 sensor is detecting a rich or lean condition for more than 10 seconds. My temp sensor was bad and never triggered the 1223 code.

Did forget to mention, O2 sensor is also less than a year old.

[N2MYE30]

I know when my cabrio throws a 1222, its because I dont drive it enough. After several miles, it disappears. It has never "bucked" though.

[603Racing]

I drive mine about 200 to 250 miles per week. 75% highway.

[jlevie]

My first suspicions would be intake leaks or a fuel system problem. A smoke test will find any intake leaks. To check for a fuel system problem, tee a gauge into the supply line for to the fuel rail and zip tie it to a windshield wiper or cowl vent so you can see what the rail pressure is when an event occurs.

[603Racing]

My first suspicions would be intake leaks or a fuel system problem. A smoke test will find any intake leaks. To check for a fuel system problem, tee a gauge into the supply line for to the fuel rail and zip tie it to a windshield wiper or cowl vent so you can see what the rail pressure is when an event occurs.

Yeah, I have access to a gauge set, but won't be able to get it until Monday. I guess I'd just have to leave it on there for a day or two to catch it when it acts up. In the mean time I may open up the tank just to visually inspect the pump... along with checking the inejector harness.

The beck/arnley pump assemblies are only $115. I may just try that as a trouble shooting measure if I can't catch it acting up with the pressure gauge.

[enigmaticdream]

Can you replicate the issue while stationary? Just giving it revs does it hit this invisible "redline"? Like this...https://www.youtube.com/watch?v=qSw7...e_gdata_player

[603Racing]

Cannot force replicate it. There is no certain RPM range that triggers it either. Sometimes it does it from a stop light, sometimes while driving 40mph, sometimes while driving 70mph, most of the time it doesn't do it at all.

[603Racing]

I ordered my fuel pump from Parts Geek and it arrived broken. Their automated return service is quick to email, but not quick to give me my damn money back. I also didn't have time to ship it back and wait for them to ship another one to me.

I didn't have time because my issue got worse. 1222 code was thrown every time I drove. I finally had a no start issue yesterday morning. I messed with the fuel pump (tapped on it and put 12 volts directly to it with the car off), then the car started right up. So I purchased a pump locally and it seems to have resolved my issue.

After replacing the pump, I drove 20 miles home, running it pretty hard on the way. I have driven 25 miles and 4 miles in two seperate trips since then with no issues, no codes, no hard starts.

[603Racing]

Ok, so I'm back on this. Car was fine for two days with the new fuel pump, about 125 miles of driving. On the way to work this morning I hit a large bump in teh road and my symptoms returned for about 3 or 4 seconds. Felt like it was starved for fuel.

So, I think I may have been experiencing two issues at the same time. I'm still about 98% sure the fuel pump was having problems. Not sure what the other problem is, but I'm thinking it's sensor or electical in nature. I'm going to check the wiring for the three relays (main, fuel, o2) and possibly swap them out to see if that helps. I'm also gong to make it a point to check my gauges next time it happens to see what they do. It's usually so brief that by the time I look at the gauges it has stopped doing it.

[jlevie]

You could have a failing fuel pump relay and/or dirty relay socket contents. Use contact cleaner on socket and insert/remove the relay a couple of times and repeat. I'd replace the main and fuel relays also.

[603Racing]

We're on the same page. Already ordered new relays and plan on checking the connections right after work today.