completely lost need some serious help with idle and low power

[bmwcarnute30]

so guys i was having a lose of power and idle issues. I own a 1990 325i vert. To start this off i will make a list of every part i have replaced.

Replaced with new:

Distributor cap
Rotor
Ignition wires
alternator
battery
oxygen sensor
MAF (with known working)
timing belt
head gasket
vacuum hoses (eliminated any leaks)
Brake Booster (had internal vaccum leak)
water pump
airfilter

Parts ive cleaned:
MAF
ICV
Had intake manifold sand blasted inside and out
Fuel injectors


THE PROBLEM!

the problem i have been chasing is that ive had hard cold starts but once its warm is will idle fine but if i give it gas it
will sometimes hesitate but then rev up nice a clean but once i let go of the gas and the rpms go down it will dip below
idle and either stall (most likely) or stutter and catch its self and continue idling. i also notice a large loss of power.

please let me know on your thoughts and if im missing some information just ask and ill give you what i know.

[bmwcarnute30]

i scanned my car for codes and im getting 1 code for icv. If i replace it i find it unlikely that its my only problem. Thoughts? also anyone got a t shaped ICV for sale

[tim88325is]

Ever do a compression and/or leak down test?

[bmwcarnute30]

Ever do a compression and/or leak down test?

i just rebuilt the head and the engine was at 90 original miles i doubt that is the problem as the car wasnt running this bad before i pulled the head.

[tim88325is]

I would still do it, the fact that the head was rebuilt even lends more to a valve issue.

Also, what issue caused you to rebuild the head?

I don't see it much on this forum but more old-timey mechanics will do a compression test with nearly any new problem to rule out serious problems and create a base line to work from.

[bmwcarnute30]

I would still do it, the fact that the head was rebuilt even lends more to a valve issue.

Also, what issue caused you to rebuild the head?

I don't see it much on this forum but more old-timey mechanics will do a compression test with nearly any new problem to rule out serious problems and create a base line to work from.

i was pulling the intake to get the injectors cleaned and then it turned into a while you're in there project.
anyway it seems almost like im running on 5 cylinders. im going to check to see if im getting spark at all 6 when i get the chance and the report back.

if not ill bring it to work and do a compression test

[tim88325is]

Since you probably took apart the C191 connector under the intake, I would make sure it is not corroded on either side where the wires feed in, under the rubber boots. That connector can be a big source of problems, even intermittent ones. Any problems can get worse if the connector is disturbed since the corroded wires are usually holding on by a thread...

[Zalmoxis]

I have the same problem, I'm replacing the coolant sensor coolant temp sensor and the water temp sensor !idk where
The purple one goes !!

[bmwcarnute30]

I have the same problem, I'm replacing the coolant sensor coolant temp sensor and the water temp sensor !idk where
The purple one goes !!

they both go in the same spot right next to each other

[Zalmoxis]

I hope that will fix my idle ! I've changed two airflowmeters I have 3icv and everything else related ! If this won't do it then .. I'll
Shoot the block with a magnum and put a 1jz or ls! Neaahhh I'm just pissed :))) thanks bmwcarnute30 !! I think I know what you're saying !! Thanks ! Right on top of the front of the block on the right side by the valve cover ! I'm heading right now to the garage ! I'll keep you posted !

[bmwcarnute30]

I hope that will fix my idle ! I've changed two airflowmeters I have 3icv and everything else related ! If this won't do it then .. I'll
Shoot the block with a magnum and put a 1jz or ls! Neaahhh I'm just pissed :))) thanks bmwcarnute30 !! I think I know what you're saying !! Thanks ! Right on top of the front of the block on the right side by the valve cover ! I'm heading right now to the garage ! I'll keep you posted !

do you have a t shaped working icv for sale?

[Zalmoxis]

so the purple goes in the 2nd hole ?! If this fixes my car I'll sell you a t shaped ICV ;)

[Zalmoxis]

The plugs are different :-/ I can't find the purple one ... Online either ! I have a 90 325i if it makes a diff

[bmwcarnute30]

The plugs are different :-/ I can't find the purple one ... Online either ! I have a 90 325i if it makes a diff

the color of the sensor should correspond to the color of the connector if irc.

[Zalmoxis]

They are not the same ! I can't find a purple switch ! fuxk this switch ! I changed the other one just in case, I found a disconnected hose it was loosing vacuum I plugged it the car runs better .. But still no choke ..