318i missing and backfires after storage - BMW Forum

deepstuff · 09-23-2011, 05:38 PM

Hi My 318i is stumbling and back firing with little power. It has been stored outside for about two years without use but started every few months. So far I've checked for vacuum leaks, cleaned the Idle control valve and added new gas. This has helped the idle somewhat. I also checked and cleaned the spark plugs; they a look good and all the same.

In the driveway it idles rough just until you give it gas. Then it smooths out. I do get back firing and missing when driving and also get backfires if its allowed to idle in the drive way for a while. No earth shattering backfires just relatively minior or quieter ones.

I also unhooked the throttle contro sensor and it makes no difference to the idle.

Where should I go and what should I do next?

Thanks!!

brettski · 09-23-2011, 10:36 PM

Try checking the MAF, it may have some crud on it that over time has oxidised. You can get a specific cleaner for hosing the MAF sensor off. See if that help. Maybe the car could do with a good long run to blow the cobwebs out.

Frozen 318i · 09-24-2011, 03:07 AM

I would get some ZMAX for the gas treatment I can almost bet you injectors are clogged or jammed up. get something to clean injectors and let it idle for sometime like 30 mins or more continue to check you temp gauge and make sure you do not over heat. also just in case it is running very lean i would check exhuast as it idles for a while to make sure it isn't getting red hot.

deepstuff · 09-24-2011, 07:32 AM

HAd it idling for a while yesterday and exhaust got very hot around the CAt. converter. Never noticed until I moved the car and seen that the grass was almost burnt. Watched exhaustr for a while next time. Cat didn't get red hot or anything?

MAF - is that the thing the electrical plug goes to next to the air filter?

Jack Dabsy · 09-24-2011, 07:42 AM

Yes thats the MAF, you have got to consider that it has been STOOD and tiny critters may have also infiltrated the intake LOL
Anything that stands for so long WILL deteriorate so go through the engine with a fine tooth-comb mate !!

Frozen 318i · 09-24-2011, 10:02 AM

Quote:

Originally Posted by Dabsy

Yes thats the MAF, you have got to consider that it has been STOOD and tiny critters may have also infiltrated the intake LOL
Anything that stands for so long WILL deteriorate so go through the engine with a fine tooth-comb mate !!

While you ask for help, also get the book on your car and learn it. If you are on this site I am assuming you will be the one working on it. this car is engineered well and after you get to know it, you will know what to look for and how to fix it. We can send you on a wild goose chase from a far but if you get the book you can do as Dabsy says and check it all the way out. Lets us know what you fine.