So got a New ICV and Fuel pump relay.. NOW WHAT!?!?

[in_si1ence]

ok so the other day i put in the new ICV and Fuel pump relay worked GREAT for a day. the next day on the way to work i was at a stop light and like 15-30 sec in idle the RED CHECK ENGINE LIGHT came on... and the idle reved a little up then down then up and back to normal. Then the light turned green.. and the proceeded to go and the light turned off. and at the next light the same thing happend. The thing is tho it only does it after a few seconds. So then i was going down a hill and i had the clutch ingaged and the shifter in nuetral and while in nuetral the same thing happend once again. So it has to do something with the idle.. Im thinkin maybe a Vacume Hose?

Please help! i Need It asap! Thanks guys

[SpecM]

-What DME do you have?
-Remove the glove box and plastic plate above it. It will say "Bosch", "MOTRONIC", and a string of numbers on it. Post the last 3 numbers of the numbers.

-I say this because some early Motronic 1.1 (p# 153, 525, etc) have idle problems. I think it was resolved with Motronic 1.3 (p# 173) in 1989, but maybe a PO put an early computer in yours? :tsk:

[in_si1ence]

The previous owner always took it to BMW dealership for service. he was the original owner and kept the car all original. so i dont think he chaged the computer. So im pretty sure its the original 173. Could it be anything else?

O and PS

I own a 1990 325i 5 speed Manual

[SpecM]

-Check vacume fittings for leaks.
-And check the DME anyway, you never know

[in_si1ence]

How should i check the vacume fittings for leaks? im sry im a newbi when it comes to older cars..

[in_si1ence]

could it me the o2 sensor

[in_si1ence]

anyone have this problem b4 that could help?

[lordofthewaters]

How should i check the vacume fittings for leaks? im sry im a newbi when it comes to older cars..

Doesn't have to be a fitting, could be cracks in hoses etc. I'd get some ether(starting fluid) in the spray can, and spray it over all the hoses etc, if you have a leak you'll find it.

As far a idling my 525 I have in mine now idles better than my 173 does, so I can't say much about that.

[SpecM]

could it me the o2 sensor

-possable

[EtaSport]

You know an easy way to check the ICV? turn the ignition on and listen for a hum being generated by the motor inside it. With it off the intake boot check to see if the swinging door is being held mostly shut.

Early Bosch motronic sucks, even the newer ones arent that great. 153, 173, 380, and 525 were put in all kinds of e30s regardless of year iirc. So you cant assume you car has a 173. Idle bumps like that tend to be software related, does it do it all the time? I wouldnt blame the o2 sensor either, as all it does is help factor when the engine is ready for closed loop operation, and "fine tune" the fuel trim while also allowing the correct fuel mixture for the catalytic convertor to operate. It switches from lean to rich to lean constantly, which is why narrowband o2 sensors dance around and are never accurate, but all the ricers think they can tune their car with them.


Do you know what code the CEL was for? You may want to check the ecu regardless because the early units only read so many fault codes.

[in_si1ence]

it was a loosly fitted hose on the IVC... Hose clamped fixed it

Thanks guys

[AdamF 88iS]

Get your DME's straight.

153 is the only 1.1 unit. It was used in 87 and early 88.

Late 88s and up are 1.3 and use 173, 380, 525, etc.

[silversleeper]

Get your DME's straight.

153 is the only 1.1 unit. It was used in 87 and early 88.

Late 88s and up are 1.3 and use 173, 380, 525, etc.

i was just about to say, because i thought that 1.1. was the double board ecu... 1.3 being the single board. and i kno my old 525 is a single board like the 173.

in regards to the 525 vs. 173, i just bought a used 173 to replace my 525. the 525 idled high at cold starts and stayed up there for some time before coming down, but never sat steady at a certain rpm. it would idle at 950 sometimes, 1100 sometimes, or 650 sometimes.

i swapped in the 173, and warmups are a lot more pleasant, but after hard driving the idle bounces for a few seconds before settling at 650.

all in all, i think all e30s suck at teh idle. :nice:

[Alluvium]

i have the EXACT same issue with my car... cept the idle thing seems speradic... :(

i got a 89 318i

so whats an IVC ?? (noob here too) "idle control valve... where is that ??

[in_si1ence]

It connects to the intake elbo

check the Bentley....