Car wont hold a steady idle... UGH!

[blackmist27]

1986 BMW 325ES
Ok.. so here is a high level over view:
i had issues with my temp gauge. it wont move more then like 1/8th up from cold. so i decided to do some research and figure out whats going on. also the cars idle has been a bit weak since i have owned the car (4 months)...

so far:
-had smoke test done.
-replaced cracking hoses
-replaced oil cap
-replaced valve cover gasket
-replace coolant temp sensor
- replaced ICV
- cold start injector
- air filter
- new DME

the only things i havent done yet are the crank case sensor or the thermo coolant temp switch. what am i missing guys? btw, here is a video of whats going on:

https://egnyte.egnyte.com/dl/h8gx5PdGDZ

its driving me crazy (no pun intended). thanks in advance!

[Kershaw]

Did you replace the 2 prong or 1 prong coolant temp sensor? You need to replace the 2 prong one.

Swap AFMs with someone and then DMEs.

[blackmist27]

Did you replace the 2 prong or 1 prong coolant temp sensor? You need to replace the 2 prong one.

Swap AFMs with someone and then DMEs.

I replaced the 1 prong sensor (should be coolant sensor). the 2 prong sensor i cant find. i bought one (for $200) and the threading was wrong so it didnt fit. id love to hear if anyone know where i can get one that actually fits. the one i bought said it was for e30s but it was too thin. see the picture

[dnguyen1963]

https://www.Blunttech.com

$200 for a water temp sensor? Someone is ripping you off.

[blackmist27]

www.Blunttech.com

$200 for a water temp sensor? Someone is ripping you off.

that wasnt for the temp sensor. thats for the thermo time switch

[MrBurgundy]

http://www.pelicanparts.com/BMW/techarticles/JF-Tech/BMW_E30_3_Series_Idle_speed_troubleshooting.htm

[blackmist27]

http://www.pelicanparts.com/BMW/tech...leshooting.htm

haha.. so timely. i just found this today and read through it. at work so i cant do any of this till later in the week... thanks for the heads up!

[blackmist27]

UPDATE:
ok so i have installed the time thermo switch and now the car does start up a bit better but once its warmed up it still surges between 500-700 rpm. also, the car tries to stall but catches itself when driven and still cold. getting to the point where i want punch myself in the nuts.

[mr.vang]

If your car is a 325e, look into the idle control module. Its a green box next to the dme.

[Kershaw]

I replaced the 1 prong sensor (should be coolant sensor). the 2 prong sensor i cant find. i bought one (for $200) and the threading was wrong so it didnt fit. id love to hear if anyone know where i can get one that actually fits. the one i bought said it was for e30s but it was too thin. see the picture

so...

1. list your make model year (do that in all future help posts too)
2. the 1 prong temp sensor (brown) is for the cluster. the 2 prong temp sensor (blue or white) is for the DME (cars computer). The blue/white one is the one that would affect the engine. It should be less than $25.
3. Try blunttech, fcpeuro, amazon, or ebay. Just google e30 temp sensor.
4. get familiar with realoem.com
...
5. https://www.fcpeuro.com/products/bmw...sor-0280130026

[blackmist27]

If your car is a 325e, look into the idle control module. Its a green box next to the dme.

Thanks ill look into that.

so...

1. list your make model year (do that in all future help posts too)
2. the 1 prong temp sensor (brown) is for the cluster. the 2 prong temp sensor (blue or white) is for the DME (cars computer). The blue/white one is the one that would affect the engine. It should be less than $25.
3. Try blunttech, fcpeuro, amazon, or ebay. Just google e30 temp sensor.
4. get familiar with realoem.com
...
5. https://www.fcpeuro.com/products/bmw...sor-0280130026

Sorry guys. you are right. i should have mentioned that the car is a 1986 325ES. as for coolant sensor is concerned, i have already replaced that. didnt do much

[blackmist27]

so...

1. list your make model year (do that in all future help posts too)
2. the 1 prong temp sensor (brown) is for the cluster. the 2 prong temp sensor (blue or white) is for the DME (cars computer). The blue/white one is the one that would affect the engine. It should be less than $25.
3. Try blunttech, fcpeuro, amazon, or ebay. Just google e30 temp sensor.
4. get familiar with realoem.com
...
5. https://www.fcpeuro.com/products/bmw...sor-0280130026

In my pictures i think that white sensor closest to the intake is what you mean, correct? that i have not replaced. ill give that a shot.

[cscracker]

Here's a picture of mine:

http://pics.deadface.org/phone/e30/IMG_20160813_202552.jpg

This is taken from the passenger side, the blue one is the one for the ECU, brown one is for the cluster. My car only has two sensors, and the other two holes have plugs in them. Your car has four sensors in the thermostat housing, so I'm not sure what the other two are for.

[estoguy]

Something else you can try is using the wider end of the spark plug gap spec. Using a gap at the wider end can help an unsteady idle as well. I use NGK ZGR5As and they are factory gapped to the wider end. Never had a problem with idle since I made the switch to them not long after getting my Eta.

[blackmist27]

thanks guys. good ideas. i did end up changing both coolant temp sensors (1 and 2 prong). i have also, cleaned the AFM and throttle body. runs a bit better but still slight surging between 750-900 rpm.