hunting engine

[superj]

91 318

engine hunts at idle in steadily growing sweeps till it dies
below 3500rpm it bucks on acceleration
dies when you let your foot off the gas
if you floor it,  accelerates smoothly
starts perfectly
all connections are good and i have fixed any vacuum leaks found

where could there be any hidden vacuum leaks?
where is the icv?  

i have the bentley for the e30 but as you fellas well know,  it does not cover this motor.  i need to fix this asap because the engine in wife's jeep liberty blew new year's eve and it was our primary family vehicle.  all i have left is my little e21 and it is tough to use for daily driving because it scraps on everything.

[92BMW318is]

hey,
i dont think its the icv. if it was it would idle eratically.

1.it could be a blocked injector/fuel system fault
2. fuel filter pluged
3. vacume leak throdel body, intake manifold or asocciated hoses
4 fuel tank vent blocked, or fuel pipes restricted
5. fuel pump faulty.

idk if you have it but do the stomp test.

turn the key to the start position, depress the gas pedal 5 times quikly.
keep trying until the engine flashes once after it flashes once it will blink out a code.
like blink pause blink blink, pause blink pause blink

that would be 1211

also if you google PDF files you can find a diffrent bmw manual and download it.

[superj]

I found the thread to download the e36 manual after I posted this so I can now test stuff.


To bad its something like 36 degrees here.  Stupid freak cold weather.

[superj]

ok,   i checked as much as my freezing fingers would allow and i everything seemed ok.  i pulled the icv and hooked a 9v battery to itto see what it would do (i read that in another thread) and it just snaps open,  no hum.  so i attempted to clean it with some chem-dip and wd-40 and it ran good for about 5 minutes and hten starting hunting again till it died.

i am going to pick up some spray carb cleaner and clean it real well and try it on the car again but since it does not hum,  i think it might have issues.  i also found out my multimeter is in need of new leads so it might help me out more to have a working meter.

i was looking over hte wiring diagram from the link provided here and it looks like the icv is controlled solely by the ecu.  until i get new leads,  i am not 100 percent sure the icv is actually getting proper power (if its supposed to get continuous 9v but it seems like it wouldn'tor how would it hold idle)  can anyone tell me what their icv wire reads while the car is in the on position and not actually running and hten also what it reads while idling?

thanks

[DesktopDave]

I think you're onto something with the ICV.  If it isn't that, clean & check your AFM too.  Sometimes the sensor arm wears out the resistor & you get all sorts of odd stuff going on.

[92BMW318is]

ok,   i checked as much as my freezing fingers would allow and i everything seemed ok.  i pulled the icv and hooked a 9v battery to itto see what it would do (i read that in another thread) and it just snaps open,  no hum.  so i attempted to clean it with some chem-dip and wd-40 and it ran good for about 5 minutes and hten starting hunting again till it died.

i am going to pick up some spray carb cleaner and clean it real well and try it on the car again but since it does not hum,  i think it might have issues.  i also found out my multimeter is in need of new leads so it might help me out more to have a working meter.

i was looking over hte wiring diagram from the link provided here and it looks like the icv is controlled solely by the ecu.  until i get new leads,  i am not 100 percent sure the icv is actually getting proper power (if its supposed to get continuous 9v but it seems like it wouldn'tor how would it hold idle)  can anyone tell me what their icv wire reads while the car is in the on position and not actually running and hten also what it reads while idling?

thanks

 icv i just went to see if mine humes it doesnt.
and my car doesnt do anything you are discriding

[superj]

ok,  thanks.

i had to drive the car around today with no icv hooked up (which only raised the idle upto about 1200) because it would hunt up and down till the car died when at a light.  i noticed after seeing daybreakers and driving the family home that the car was acting normalish,  no bucking.  so i plugged the icv back in and the car has been fine ever since.

the wife thinks it was bad gas, or water in the tank, from sitting since this car was not a daily driver, till her jeep lost its engine