idle and hard start problems

[harold30]

hi guys,

im totally new to the world of cars. i bought my first car "1990 e30 325i" automatic sedan 6 months ago and problems start popping out since i drove it.

i've been reading/searching for a month or two and applied some suggestions one step at a time.

i changed most parts namely:
- water pump
- rebuilt power steering rack
- suspension (shocks and springs)
- ball joints
- rack end/tie rod
- stabilizer link
- cylinder head gasket
- vacuum hoses
- icv and idle control hose
- intake boot
- o2 sensor
- fuel filter
- changed oil twice (or every 3 months, changed oil filter last april)

what really bothers me are:
1) rough idle surging from 600 - 900 rpm
- this only happens when the engine is cold and will take like 4-5 mins (fuel economy counter is freaking out like moving from left end to right and vice versa).
- when the engine is warmed-up, idle stabilize at 750rpm (i adjusted something in throttle to make it 750 as most suggested, it was 600 before). also, CEL will show up when car is idle and went out when accelerated.
- did a stomp test and got 1222 fault code.
- check c191 multiplug and it's clean.
- sprayed carb cleaner on suspecting areas like fuel injectors, intake gasket, throttle body, oil cap, dipstick, etc and found nothing.

2) hard start
- this will happen when the engine is warm. but one click if engine is cold.

i know my problems has been all around the net and other members here encountered these issues. since im new to all of these, i need some suggestions from experts and those who solved them. i read same problems over and over again but with different solutions. though, im open to try anything.

i want to solve the idle issue first before fixing the hard start (one step at a time). i really need your help guys what to do next.

here's what i have in mind (results from reading the net)
1) try other afm before buying as it's expensive
2) coolant temp sensor
3) throttle position sensor
4) fuel pressure regulator

what do you think?

please post your suggestions here.

thanks in advance.
- harold

[harold30]

any suggestions anyone?

[davem]

intake manifold gasket, i bet if you have a smoke test done you'll notice it, but I would just pull the manifold off, replace the seals & gaskets, replace the coolant temp sensor while you're in there, and you should be good

i had similar symptoms and carb cleaner just doesn't cut it for isolating vacuum leaks

[woodisgood]

Vacuum leaks...get to checkin. Don't forget dipstick and oil cap plus the fifty million tiny black hoses.

[harold30]

idle and hard start problems

intake manifold gasket, i bet if you have a smoke test done you'll notice it, but I would just pull the manifold off, replace the seals & gaskets, replace the coolant temp sensor while you're in there, and you should be good

i had similar symptoms and carb cleaner just doesn't cut it for isolating vacuum leaks

i thought of changing them but i have to check first if my afm is working fine. i live in the philippines and order parts in the U.S. it takes some time for my items to arrive. i thought buying them as one package though.

Vacuum leaks...get to checkin. Don't forget dipstick and oil cap plus the fifty million tiny black hoses.

yeah, it's a vacuum leaks but i have to find where because i already changed vacuum hoses.

thanks a lot for your inputs guys, really appreciate it.

[harold30]

update. i tested my afm by pulling the electrical connector and the engine went off. my friend told me that engine dies after pulling the connector for working afm and rev up if bad one. it's a great news for me so i can't spend on expensive part.

ill be purchasing next the intake manifold gasket and coolant temp sensor. what color should it be? is it blue or brown? realoem shows 1-pol type with part # 12621710512 and refer to pelicanparts.com and it shows a brown one with FAE brand.

questions are:
1) is there any big difference between blue and brown?
2) can i use the blue one instead of brown for my 90 325i eta? (i believe bosch is more realible than other brand like fae)

what do you think?

TIA

[davem]

update. i tested my afm by pulling the electrical connector and the engine went off. my friend told me that engine dies after pulling the connector for working afm and rev up if bad one. it's a great news for me so i can't spend on expensive part.

ill be purchasing next the intake manifold gasket and coolant temp sensor. what color should it be? is it blue or brown? realoem shows 1-pol type with part # 12621710512 and refer to pelicanparts.com and it shows a brown one with FAE brand.

questions are:
1) is there any big difference between blue and brown?
2) can i use the blue one instead of brown for my 90 325i eta? (i believe bosch is more realible than other brand like fae)

what do you think?

TIA

brown is the coolant temp sender for the temperature gauge in your cluster

blue is the sender for the computer

[harold30]

@davem, thanks a lot for your suggestions. ill be getting the blue coolant temp sensor and gaskets. will update this thread after a week or 2 for any results. it will take time for my orders arrive here in my place.

[harold30]

Update: problem solved with temp sensor. thanks a lot for your help guys. i really appreciate it. r3v rocks!

[harold30]

Update: i had my injectors clean and changed filter, o-rings and pintle caps. hard start when engine is warm is gone and idle smooth as silk...