85 Running Rich at Idle Only
02-11-2009, 02:17 AM
#61
Racer
Thread Starter
Update:
Had my buddy hook up the LM1 and after some tweeking we got 14.7!!!
The new AFM and new refurbed BMW "364" Fuel Injectors was defintely leaner than my old ones and we had to loosen the tension spring on the AFM to get the proper reading on the LM1.
The reason for this, the AFM appeared to be too tight so it would not allow the WOT to read at 13.1. It was reading 14.2 at Full Throttle (WOT). Once loosened 4 clicks we got the desired readings.
The idle is so smooth now. I never knew how the idle was supposed to be but now I know. Can't get the stupid grin off of my face.
The RPM idle down from speed is so smooth and settled right down to 880RPMs, dead on.
Had my buddy hook up the LM1 and after some tweeking we got 14.7!!!
The new AFM and new refurbed BMW "364" Fuel Injectors was defintely leaner than my old ones and we had to loosen the tension spring on the AFM to get the proper reading on the LM1.
The reason for this, the AFM appeared to be too tight so it would not allow the WOT to read at 13.1. It was reading 14.2 at Full Throttle (WOT). Once loosened 4 clicks we got the desired readings.
The idle is so smooth now. I never knew how the idle was supposed to be but now I know. Can't get the stupid grin off of my face.
The RPM idle down from speed is so smooth and settled right down to 880RPMs, dead on.
Last edited by DRACO A5OG; 02-12-2009 at 07:40 PM.
02-11-2009, 03:54 PM
#62
I haddah Google dat
Rennlist Member
Rennlist Member
You switched to BMW injectors? I missed that.
And you adjust your afr to 14.7 at 880 rpm? I must be doing something wrong because my car wont run that lean. How did you disable the O2 sensor? Did you just unplug the two prong connector?
Thanks!
And you adjust your afr to 14.7 at 880 rpm? I must be doing something wrong because my car wont run that lean. How did you disable the O2 sensor? Did you just unplug the two prong connector?
Thanks!
02-11-2009, 04:42 PM
#63
Racer
Thread Starter
Yeap, after reading Sal aka scarcelar's thread on alternative fuel injectors for 3.2. I was convinced. Especially when he stated and showed it ran leaner. I always had richness issues so I figured slightly lean (.10) is better than too rich.
Two Pronged? I just disconnected the black shielded wire with the huge insulation rubber plug, connected the LM1 to the exhaust after she was upto running temp. I think my 85 is set up a bit differently then post 86's on the O2 sensor. At first, she fluctuated from 14.5 to 14.9 then settled steady at 14.7. We were both surprised and smiling.
Plugged the O2S back and we were on the FWY, with the LM1 and computer hooked up to tweek the chip and at full throttle, the O2s appeared to be stuck at 14.7, too lean. We loosened the AFM spring 4 clicks and it resolved the stuck O2S issue and we were reading 13.1 at WOT. It was cool because before the adjustment, at WOT I saw un-burnt fuel out the exhaust, after the asjustment no more smoke, no pings.
Two Pronged? I just disconnected the black shielded wire with the huge insulation rubber plug, connected the LM1 to the exhaust after she was upto running temp. I think my 85 is set up a bit differently then post 86's on the O2 sensor. At first, she fluctuated from 14.5 to 14.9 then settled steady at 14.7. We were both surprised and smiling.
Plugged the O2S back and we were on the FWY, with the LM1 and computer hooked up to tweek the chip and at full throttle, the O2s appeared to be stuck at 14.7, too lean. We loosened the AFM spring 4 clicks and it resolved the stuck O2S issue and we were reading 13.1 at WOT. It was cool because before the adjustment, at WOT I saw un-burnt fuel out the exhaust, after the asjustment no more smoke, no pings.
02-11-2009, 04:56 PM
#64
I haddah Google dat
Rennlist Member
Rennlist Member
oh cool. I have to try that. I don't know if my afm spring is adjustable. Do you know what your afr is at idle?
I think the black wire is the heater wire for the O2 sensor. On mine, the garage glued it together because some dork broke it when they were working on it. I have to go back and fix it with real parts I guess.
I think the black wire is the heater wire for the O2 sensor. On mine, the garage glued it together because some dork broke it when they were working on it. I have to go back and fix it with real parts I guess.
02-11-2009, 05:25 PM
#65
Racer
Thread Starter
The AFM tensioner spring is adjustable underneath the cover held by a metal clip, but CAUTION. My understanding is that it will through the entire mapping off. That is why I had a computer hooked up along with the LM1 to tweek the mapping to accomodate the looser tension on the AFM.
If I had to, I would loosen the AFM tension spring then Dyno it and send the print out to Steve and ask him to re-map the chip?
We determined that the AFM tension was set at the factory so it will not look the same for everyone.
I dorked my plug ( I swear it was black ). So I used male and female spades with insulation shield for my O2 Sensor. Works perfectly. Just make ceratin the metal mesh shield is covered with heat shrink wrap as not to cause a short.
If I had to, I would loosen the AFM tension spring then Dyno it and send the print out to Steve and ask him to re-map the chip?
We determined that the AFM tension was set at the factory so it will not look the same for everyone.
I dorked my plug ( I swear it was black ). So I used male and female spades with insulation shield for my O2 Sensor. Works perfectly. Just make ceratin the metal mesh shield is covered with heat shrink wrap as not to cause a short.
02-11-2009, 08:48 PM
#66
I haddah Google dat
Rennlist Member
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MY AFM is still glued all together. I haven't opened it up.
That sounds like a good fix for the O2 plug. Come to think of it, the same mechanic who broke it told me it is the O2 heating circuit. He could be wrong too!! I need to re-check my fuel pressure, make sure injectors are all working, etc.
That sounds like a good fix for the O2 plug. Come to think of it, the same mechanic who broke it told me it is the O2 heating circuit. He could be wrong too!! I need to re-check my fuel pressure, make sure injectors are all working, etc.
02-11-2009, 09:00 PM
#67
Racer
Thread Starter
A virgin AFM, how many miles do you have on her? If she is over 75K, you may want to take a peek to see if the tracks are too worn in. I used a clean pencil eraser to gently rub away debris and smooth out the grooves. The grooves actually disappeared. Be Gentle!
If the O2S connects to a Bullet connection with discolored white shroud, that is your sensor circuit. the two pronged connector is your heating circuit (this connector is made of black plastic/rubber housing).
Your fuel pressure check method worked great, thanks again but i did not pinch of the rear lines because she passed the pressure test with flying colors.
As I mentioned, while the car is on and with the LM1 connected, see if by pulling each injector one at a time if there are extreme variation in readings i.e. if you pull one and get a 18.0+ reading, they should all be the same as you pull one at a time. My #2 read 16.2+/- so I deduced that was the bad injector, leaking too much fuel = rich idle
If the O2S connects to a Bullet connection with discolored white shroud, that is your sensor circuit. the two pronged connector is your heating circuit (this connector is made of black plastic/rubber housing).
Your fuel pressure check method worked great, thanks again but i did not pinch of the rear lines because she passed the pressure test with flying colors.
As I mentioned, while the car is on and with the LM1 connected, see if by pulling each injector one at a time if there are extreme variation in readings i.e. if you pull one and get a 18.0+ reading, they should all be the same as you pull one at a time. My #2 read 16.2+/- so I deduced that was the bad injector, leaking too much fuel = rich idle
02-11-2009, 10:12 PM
#68
I haddah Google dat
Rennlist Member
Rennlist Member
oh..sounds like the sensor circuit is broken. It has a yellow plastic plug with black rubber or something on the outside. It is bolted down in the engine compartment, and has a single black wire. That is the one that Mike at Sigfreid's broke. He glued it back together. Maybe that connection is now bad.
How did you get the afm open? Did you cut it open with a Dremel? That plastic looks thick. It is seriously glued together.
How did you get the afm open? Did you cut it open with a Dremel? That plastic looks thick. It is seriously glued together.
02-12-2009, 02:08 AM
#69
"We determined that the AFM tension was set at the factory so it will not look the same for everyone."
Actually, that was not the case. All the AFMs were preset by Bosch to match
the DME maps. Remember, the 3.2 Carrera was a production vehicle where
all the engines were basically the same with very very insignificant minor
variations in engines, sensors, and DMEs.
"My understanding is that it will through the entire mapping off."
That's correct. It will richen the mixture if the rest-point of the wiper
is not adjusted to compensate for the adjusted spring. If done correctly,
the engine becomes more responsive without being overly rich.
Actually, that was not the case. All the AFMs were preset by Bosch to match
the DME maps. Remember, the 3.2 Carrera was a production vehicle where
all the engines were basically the same with very very insignificant minor
variations in engines, sensors, and DMEs.
"My understanding is that it will through the entire mapping off."
That's correct. It will richen the mixture if the rest-point of the wiper
is not adjusted to compensate for the adjusted spring. If done correctly,
the engine becomes more responsive without being overly rich.
02-12-2009, 02:31 PM
#70
Racer
Thread Starter
oh..sounds like the sensor circuit is broken. It has a yellow plastic plug with black rubber or something on the outside. It is bolted down in the engine compartment, and has a single black wire. That is the one that Mike at Sigfreid's broke. He glued it back together. Maybe that connection is now bad.
How did you get the afm open? Did you cut it open with a Dremel? That plastic looks thick. It is seriously glued together.
How did you get the afm open? Did you cut it open with a Dremel? That plastic looks thick. It is seriously glued together.
AFM, Use a knife to trim off the excess silicone and places knife in between the metal housing and plastic lip trying to get all teh silicone off then use a metal 2" puddy knife to gently push open the lid under the lip. Doing little at a time will allow the lip from being damaged.
Once Open you will see how easily it comes off. Just use a little silicon glue to seal it up later, you may want to go back in there at a later time.
Hey Loren, Thanks for the Feed back. That is what we thought about the AFM but our Eye's must have been playing tricks on both of us. But the Sprocket was definitly different by 1/2 a teeth. The adjustment cured her troubles. I must just have a freak AFM built in 88. I wonder how many freaks are out there?
