318i Stalls on Highway!

[rtilney]

Hi,

I just started having a problem with my '84 318i stalling on the highway and in regular city driving. The car doesn't sputter or hesitate or give any warning it is about to stall. (Very nerve-racking on the highway!) The radio and lights all stay on. I can usually re-start the car after I let it sit from 30 seconds to 5 minutes, one time even immediately after.

So far I have tried replacing the ignition coil, fuel filter, and worn vacumn hoses to no avail. I am planning on replacing the oxygen sensor too, it looked pretty corroded when I pulled it out.

I ruled out fuel delivery because I don't have any sputtering or hesitation symptoms, am I off base?

Has anybody had this problem happen to them? What do you think I should try next? I haven't found any good troubleshooting advice online or in Bently.

Thanks!

 

[KC Ron Carter]

Some TS hints

If the issue is self correcting with no changes it is normally an electrical issue.

The o2 sensor may need changed but it should not affect the operation in a stalling issue.

If you have an OBC, it may be the OBC relay wich has the electrical feed going through it so it can act as a security shutoff.

The Ignition Control Module on a BMW is a good starting point if you need a positive part change. The biggest point there is it must have a coating of silicone grease between the module and the mounting or the module will also show the results you are seeing. The coating acts as a connection to allow the heat to transfer.

Keeping a spare sparkplug grounded by wired to the engine, to test with the next time it acts up. That will show if it is ignition or a fuel issue.

The EFI fuel systems will give some of the same symptoms if it is a fuel pump control issue.

Later,

 

[rtilney]

Well, tried the Oxygen Sensor, still stalls. My car doesn't have an OBC that i know of, it is an 84 318i. Let's see, I haven't replaced the Fuel Pump yet...by the time I am done I will have a brand new Bimmer!

Other suggestions? Anyone?

 

[Rukus]

Trust me on this one, same problem happenned to my car. YOur catylytic converter is plugging up. get that thing removed, or replaced and it will solve your problem guaranteed (this is not a guarantee)

You can also check your afm. Sometimes they like to stick for no reason. Thats what fried my ECU.

Jared

 

[rtilney]

Hmmm, never thought of that. My Catylitic Converter does make some rattling noises, I guess it could be damaged inside.

Another thing, the car will stall at about the same duration or distance. (about 7 miles or 10 minutes) I have been driving the same route to figure out if it is consistant and it certainly is. Do you think this could be heat related within the CC? Why wouldn't the car restart right away, sometimes 5 minutes?

Sorry, lot's of questions. I just want to make sure I don't replace expensive parts only to find that the problem still exists. I appreciate the help so far!

 

[nadroj]

just chop the exahst at the CC
It will sound like rice but atleast your problem maybe fixed

 

[Rukus]

Well, if the exhaust is all plugged up, from a plugged CC, of course the car won't start. What exactly goes on inside the CC when it warms up/ cools down is beyond me. But my car on the highway at constant speeds would buck and chug, the fuel mileage guage go possessed, and i would pull over for a coffee, let it cool off and it would be fine for another hour. I know the distance / time if different, but it doesn't rule it out.

Getting a cat removed and a pipe welded in there by muffler shop is like $50cnd. like $35 american. thats not a pricy mod.

 

[Rukus]

Just to let you know about the oxygen sensor, a worn one on that car wouldn't cause hte car to die, UNLESS it was shorting out some how. Then what it does is it will shutdown the ECU so that it doesn't fry. Then when you start it back up, it will either receive a signal from the oxygen sensor or it will not. It will revert to the last good setting or to a default setting.

So check for any faulty wiring from the oxygen sensor as well. That could be the culprit. OR to tel lyou the truth, a worn one could be shorting the wire out, causing the ECU to shut down.

Thats another thought i jsut had on my mind.

TRY unplugging the oxygen sensor and run it like that and see what happens. check for worn wire between the ECU and firewall and between the firewall and oxygen sensor.

 

[rtilney]

Thanks Rukus, I will take a look at this more during the week and will let you know what I find. The CC makes sense, but I want to test the fuel pump and fuel pump relay first.

Again, I am getting no chugging or buckin' when the car dies, the engine just turns off.

 

[Rukus]

well if you find out what it is, let me know, cuz i drive the same car. It always helps to know one more thing about your car