M43 Won't idle - Cuts out

[Ventojetta]

Hi all,

Was wondering if someone could help me out. Have a E46 estate, 318i with the M43 1.8 engine in it.

Car starts fine, but won't idle. As soon as I leave my foot off the accelerator and the rev's drop it cuts out. I'm sure this is probably an easy fix that i'm overlooking.

I have cleaned the throttle body and have also cleaned the ICV. I've checked for air leaks and couldn't find any. MAF looks fine too.

Could it be the CCV? I've checked the breather hose's coming off it and they don't look in the best shape (dirty and old) so wondering if that's potentially my problem?

Any other suggestions at what may be at fault or has anyone else had this problem?

Car has been laid up about 4 - 5 months but didn't have this issue before being parked up.

Many thanks in advance.

[Venom]

Hi all,

Was wondering if someone could help me out. Have a E46 estate, 318i with the M43 1.8 engine in it.

Car starts fine, but won't idle. As soon as I leave my foot off the accelerator and the rev's drop it cuts out. I'm sure this is probably an easy fix that i'm overlooking.

I have cleaned the throttle body and have also cleaned the ICV. I've checked for air leaks and couldn't find any. MAF looks fine too.

Could it be the CCV? I've checked the breather hose's coming off it and they don't look in the best shape (dirty and old) so wondering if that's potentially my problem?

Any other suggestions at what may be at fault or has anyone else had this problem?

Car has been laid up about 4 - 5 months but didn't have this issue before being parked up.

Many thanks in advance.

Petrol gone bad or fuel pressure regulator. I have an m43 from an e36 for parts of you need any bits.

[Ventojetta]

Thanks! I'll keep that in mind. I'll throw in some new petrol and see, worth a try

[Owen]

It wouldn't be the CCV, and the quick way to isolate the MAF is to disconnect it. Without the dynamic data from the MAF, the ECU will just go to a standard default instead and the car should run fine once it's warmed up - down in power, but fine.

Check your oil cap is on right. My old 318ci would hunt severely up and down the rev range almost stalling if the oil cap wasn't 100% on tight.

Other than that, you're into the basics. Fuel pump, cleaning the throttle which is much easier on the 318 than a 6 cyl as it's right behind the airbox. The only concrete way to test for perished hoses is to get a smoke test done at a garage that has the right equipment.

[Ventojetta]

It wouldn't be the CCV, and the quick way to isolate the MAF is to disconnect it. Without the dynamic data from the MAF, the ECU will just go to a standard default instead and the car should run fine once it's warmed up - down in power, but fine.

Check your oil cap is on right. My old 318ci would hunt severely up and down the rev range almost stalling if the oil cap wasn't 100% on tight.

Other than that, you're into the basics. Fuel pump, cleaning the throttle which is much easier on the 318 than a 6 cyl as it's right behind the airbox. The only concrete way to test for perished hoses is to get a smoke test done at a garage that has the right equipment.

Ran it with the MAF disconnected and still the same issue unfortunately. Fuel pump seems to be fine, can hear it running without much strain on it. Throttle has been cleaned but i'll take it off and inspect for good measure. Car is declared off the road so can't take it to a garage, but will double check all air hoses and see. No engine lights or anything on either which is odd which leads me to believe its something small. Will take plugs out and give them a clean too. Oil cap is on correctly too.

[Roberto]

Fuel filter/fuel lines partially clogged?