help my old winter beater

[bikerbill2021]

hey guys/gals

so ill keep this short, 87 325IS, having a bit of problem with her. what would cause a a slight hesitation and consitent loss of power? about two days ago i was putting her thru its paces, having a great time ripping up some back roads, and she was running superb. i let it sit over night and came back to drive the next day and had these symptoms im faced with now.

i check the plugs, wires, cap and rotor, grounds, and threw in some injector cleaner in the tank, and its still the same, any thoughts?

thanks

Tyler

[16v of E30]

scrape off the metal connetion points in your dist cap, maybe change your ignition rotor too.

i had that problem at the autocross track in my 16v jetta. worked fine after that...

[bikerbill2021]

scrape off the metal connetion points in your dist cap, maybe change your ignition rotor too.

i had that problem at the autocross track in my 16v jetta. worked fine after that...

didnt replace the rotor, but when i did check the cap, i scrapped off all the carbon etc on the terminals, but to no avail :/

[ZombiE30]

is it all the time, or just at certain speeds/RPMs?

mine did this, and it turned out to be dead spots in the AFM. The vane potentiometer primarily sits in two places; idle and cruise, and it had worn through the contacts at those points and showed several segments of infinite resistance when I hooked up an ohmmeter. I don't remember which of the three contacts on the AFM you hook the leads to, but clamp those on and push the vane all the way open and closed. The bentley has the resistance specs, but it basically should be a smooth rising/falling of resistance, indicating solid continuity through the whole spectrum.

another quick way to test that is to unplug the AFM and drive it (will accelerate like shit). compare the symptoms and away we go!

[bikerbill2021]

is it all the time, or just at certain speeds/RPMs?

mine did this, and it turned out to be dead spots in the AFM.

another quick way to test that is to unplug the AFM and drive it (will accelerate like shit)

im glad you posted this, b/c i think that may be my problem

so i decided to hop in the bay and try unplugging such things as the 02 sensor etc. i noticed no difference with the 02 sensor unplugged, a slight rise in idle with the TPS unplugged (normal from my expierences with those stupid sensors) and a rise in idle when i pulled the FPR line off, all normal stuff.

HOWEVER, i unplugged the AFM, and the motor continued to run normally. when i modulated the throttle it would choke a bit here and there, but still ran more or less normal. i cleaned the AFM two days ago when i went through the car and checked things, but perhaps its failing?

Zombie, does this sound familiar? thanks guys

[ZombiE30]

yes, that sounds very familiar!
I spent a week searching for vacuum leaks before i figured out it was the AFM.....and those were some very frustrating weeks of driving!

Do you have an voltmeter?
It's important to check the AFM readings itself, because there's a snowball's chance in hell that it could be the wiring (but it's probably the AFM).

first just push the flap with your finger and make sure it isn't binding anywhere.
then attach the voltmeter leads to terminal 2 and 3 on the AFM. (set for resistance)

if your ECM# is 0 280 001 106/111/122 then it should read 70-800 ohms
if your ECM# is anything else then it should read 475-1900 ohms

if at any point your voltmeter reads OL or infinity, then the AFM needs to be replaced
(~30 from a junkyard.....but bring your voltmeter and test it there! don't wanna buy useless crap....)

[xwill112x]

might have broken a rocker arm?

[bikerbill2021]

yea ive got a mulitmeter, ill have to check it out tomorrow, as im running out of light today.

the problem has gotten much worse sadly. i had to get it back to my apt an hour away from my moms, and all was the same, got within ten mins of my house and it got much worse, to the point where i was stalling at stop lights. i had to keep the revs up to keep it from stalling, and basically floor it to get it home

i checked to see if my cat was glowing just in case it may be clogged once i got it in my driveway, and while i noticed it looked hot (heat waves) it wasnt glowing, hoping thats not the problem

[bikerbill2021]

aight busted out the multimeter today and pulled the AFM to check it out

the code on the AFM was 0 280 202 082, so i guess it should have read from 475-1900

well, with the AFM closed and untouched, it started at right around 600 ohms. while pushing on it, it would jump to a max of about 1100 ohms, and fluctuate from 900 to 1100 while continuing to push on it. once i pushed it to full open, it would drop drastically to about 120 ohms

so im assuming my AFM is shot as its not in spec with what Zombie said? it never read OL or infinity, but these readings seem very goofy. hoping this is the problem, what do you guys think?

[ZombiE30]

that is strange......
make sure to open the flap REALLY slow, becuase the OL portions can be very small but have a large impact on the sensor's performance. it took 5-10min of fiddling with mine to find the bad spots.

I'm thinking that is the problem, but see if you can find one in the junkyard. Test it there, and grab one where the readings make more sense. Or borrow a working one from an e30 buddy, just to be sure that is the issue.

they shouldn't be expensive as long as you don't buy it from the stealership....

[bikerbill2021]

haha nah no dealership for me, tooooo much money

i opened it pretty slowly, but ill have to try it again to see. but for the moment, ill try tracking down another AFM.

someone over on e30tech mentioned that my cat could be the culprit. ive actually never experienced a cat converter going bad, so i wouldnt know what the symptons are, except for a glowing cat. does this sound like a clogged cat to anyone by any chance?

[bikerbill2021]

or perhaps the crank position sensor? more suggestions from e30tech

[bikerbill2021]

pulled the plugs today, im getting spark and fuel, as the plugs were wet from fuel after trying to start it. im gonna check the air temp sensor tonight after the AFM has warmed up in my apt

it basically fires up then bogs and dies before it can get running. im banging my head here, so typical this shit happens in the middle of a snow storm

[bikerbill2021]

bump, still no such luck with getting her going. been busy at work so havent had much time to work on it

[ZombiE30]

did you ever confirm/deny the AFM?
you said that the symptoms were the same with it plugged in or not, which is pretty strong indication that it's jacked up....
you have brought up some other good options, but I just think that the AFM should be tested 100% good before you go off looking elsewhere.