help! at the end of my rope with drivablity issues.

[under the radar]

help me, this car is very close to being scrapped. i'm out of ideas.

the car will start, idle fine, and drive for a few minutes and then it will choke, buck, sputter and lose all power, but it wont die out, it will still idle. but if i give any gas it chokes.

i thought i had it narrowed down to a bad thermo time switch. when the car would act up, if i unplug the thermo time, it would run better. i replaced it with a new bosch unit and it ran great for a few days, i was happy...and then...yes the choking came back...so here i am, asking for help.

things that have been replaced or swapped out
ECU
fuel pres reg
fuel pumps
fuel filter
combo relay
AFM
distributor
plugs/wires
ignition control box
coolant temp sensor
ground/ wires/conectors cleaned

i'm at the end of the line here and i'm starting to think about stripping the good stuff from the car and sending it off to be recycled.

[grumpsjr]

I wonder if you have a leaking cold start valve?  

Also, you replaced the distributor - have you checked the timing, and made sure the vacuum advance is working properly?  


Have you checked the throttle switches for proper adjustment?  Also, make sure your oil cap and dipstick are sealing and your rubber intake boots are sealing properly.  


I also had a stuck Idle Compensation Valve that the AC relies on that was causing some driveability issues on my car.


Keep us posted, but don't junk it yet. I fought a driveability issue on my car for over a year.
Brian


Finally, try putting your hand on the AFM when the car is acting up.  If it smooths out, you have a bad ground somewhere still.

On Tue, Oct 5, 2010 at 4:10 PM, under the radar <paulpommes@gmail.com (paulpommes@gmail.com)> wrote:

help me, this car is very close to being scrapped. i'm out of ideas.

the car will start, idle fine, and drive for a few minutes and then it will choke, buck, sputter and lose all power, but it wont die out, it will still idle. but if i give any gas it chokes.

i thought i had it narrowed down to a bad thermo time switch. when the car would act up, if i unplug the thermo time, it would run better. i replaced it with a new bosch unit and it ran great for a few days, i was happy...and then...yes the choking came back...so here i am, asking for help.

things that have been replaced or swapped out
ECU
fuel pres reg
fuel pumps
fuel filter
combo relay
AFM
distributor
plugs/wires
ignition control box
coolant temp sensor
ground/ wires/conectors cleaned

i'm at the end of the line here and i'm starting to think about stripping the good stuff from the car and sending it off to be recycled.



the early nineties called. they want their awesome back

OO==00==OO

Post generated using Mail2Forum (http://www.mail2forum.com)

[under the radar]

yes, the car is timed properly and all possible vac leaks are accounted for...AFM is grounded. idle/wot switches adjusted.

this is an intermittent problem. the car is capable of running really well.

tell me more about the AC compensation valve.

[socalfiver]

what year is your car? on my '80, the a/c compensation valve is gold, located above the aux air valve and has 2 wire connectors (not bosch connector) coming out of the end opposite the vacuum line.

[marc79euro645]

hard to say but I'd suspect the afm.
good luck
marc

[under the radar]

eh, sorry guys. its a '79 528i manual trans.

i scored a new AFM on ebay, plus i had an extra used one. switching between all three and no change in the symptoms but it runs best with the new one.

[JoshInAtlanta]

I had similar issues, though not as bad as yours sound.

I had a slight improvement with a different AFM, and a huge improvement with a different aux. air valve. Have you replaced that yet?