DSM AFC huge problem

[^tyrant^]

ok i got the supermap flashed to the unit, and its the strangest thing the car will drive great for awhile and then all of a sudden it starts running like ass.

when it does this it seems to be running way rich cus it starts the putter and massive black smoke coming from exhaust.

from what i have noticed it seems to start doing this at around 2800rpm and if i keep on the gas it bucks violenty untill about 4000rpm then it feels like a sling shot and pulls realy hard.

the last time it started doing this, i checked the maps and some how they got reset to the maps that was on it before i put the supermap on.

it started doing this agian tonite so i checked the maps and there fine, i reflashed just for the fun of it, and that was when i got home ill see how it drives tomarow.

all the wires seem to be in place and nothing seems to be loose or anything.

anyone got any ideas at all? i just changed the plugs i think i got them gaped at 32, they are Denso KJ22CRL8

 

[31R]

You know what, now that you said that, i remember this happening to me. I thought nothing of it till now. Hmmm... it seems like the AFC drops the map.

 

[^tyrant^]

ya prety much thats what it seems like is going on, this is my second afc unit, the first one came DOA some internal problem it was giving of some high voltages kept tossing a CEL.

but the new one runs great for a while then slowly starts acting up.

im running stock boost, my gauge says 5-6psi

i got a perrin SRI, stock intercooler pipes and intercooler, stock downpipe with cats, 3" catback

i weill be putting on turbohoses hardpipes and SMIC friday i hope.

i realy hope i can figure out why it is doing this, if not im going to have to come off.

 

[Rawyzf]

Interesting....I will be installing my AFC this week. I will look for this issue. How long did it seem to hold the map?

 

[MSP #167]

i would contact dsmconvert......i've had absolutly no problems with mine and i've had it on my car since the first batch came out (december i think). I've put on and taken off a few different maps that have been out for it and never ran into a problem.

 

[CasopoliS]

Very interesting. Maybe this is why mine jerks right around 3k and 4k right now. I will try to re-load the MAP.
this reminds me how much I wish I had timing control.

 

[kicker22705]

check your vacuume line. one time i was messing w/ the afc and the vacuum hose got kinked, making my car drive exactly as you describe.

 

[31R]

I too get that same jerk between 3-4k. I though maybe its because i have to get it tuned to my mods, but i think i am close to the same mods as casopolis and he is getting the same jerk. Hmm.....

 

[hazeXban]

Best of luck with this problem. Let us know what happens. I just bought this used and hope I don't have any troubles with it.

Pete

 

[DSMConvert]

A few people have had that happen and the problem was either a gunked up 02 sensor or a loose vac, loose vac lines being the predominant cause...what generally happens is that the vac source to the afc fluctuates as the line becomes loose and thus the afc cant compensate for the rapid fluctuation in pressures. I've also had 2 people who had fouled up 02 sensors that were sending bad readings and had 1 person that had an actual boost leak that caused the problem...I would first check vac lines for leaks and kinks, then pull your 1st 02 sensor and clean out with some brake parts cleaner, then boost leaks last. As far as dropping the maps we stil lcan't seem to duplicate the problem here, so I'm not sure what/how is causing it. I think tyrant is the only case thus far though that we've had. At any rate I'm always around so if that doesnt fix the problem let me know and we'll figure out a solution, even if it requires replacing the unit.

 

[CasopoliS]

A few people have had that happen and the problem was either a gunked up 02 sensor or a loose vac, loose vac lines being the predominant cause...what generally happens is that the vac source to the afc fluctuates as the line becomes loose and thus the afc cant compensate for the rapid fluctuation in pressures. I've also had 2 people who had fouled up 02 sensors that were sending bad readings and had 1 person that had an actual boost leak that caused the problem...I would first check vac lines for leaks and kinks, then pull your 1st 02 sensor and clean out with some brake parts cleaner, then boost leaks last. As far as dropping the maps we stil lcan't seem to duplicate the problem here, so I'm not sure what/how is causing it. I think tyrant is the only case thus far though that we've had. At any rate I'm always around so if that doesnt fix the problem let me know and we'll figure out a solution, even if it requires replacing the unit.

Thank you for the response. I will look at all my lines, and also verify that I still have the supermap uploaded. Did anyone verify that the new FMIC map was running good AFRs at high rpm? I do not have a WB O2 yet, so I am not going to upload it. Thanks!

 

[MSP #167]

Thank you for the response. I will look at all my lines, and also verify that I still have the supermap uploaded. Did anyone verify that the new FMIC map was running good AFRs at high rpm? I do not have a WB O2 yet, so I am not going to upload it. Thanks!

i ran that map for about a week and had nothing but problems, i even threw a check engine light and my car went into limp mode or something because it was running way too rich, i was shooting out huge flames and my gas milege sucked ass. I think there is something really wrong with that map, i would not run it if i were you.

 

[^tyrant^]

i have a golden eagle vac block running my boost gauge, afc, and bov. the vac block is taped in the brake booster line, fas as i know there is no vac leak it reads 22on vac and when in boost around 5-6psi.

but i will check the line going to the afc unit to see if its pinched anywere.

the first 02 sensor is the one going into the manifold right?

 

[peepsalot]

the first 02 sensor is the one going into the manifold right?

Yes

 

[^tyrant^]

ok, i know i use to throw a CEL about the first o2 sensor when ever i had my injen intake on the car, just when that intake was on.

switched to a perrin and have never had a cel agian from it.

 

[CasopoliS]

Does the AFC clear the MAP if it loses power?

 

[peepsalot]

ok, i know i use to throw a CEL about the first o2 sensor when ever i had my injen intake on the car, just when that intake was on.

switched to a perrin and have never had a cel agian from it.

that's bizarre, intake shouldn't affect the O2 sensor at all really. What was the code? Maybe it was simply a coincidence that the code came on for the injen.

 

[Rainman]

I have never had any major issues with the AFC. I am running the stock super-map with stock boost and an FMIC. My wideband shows that my AFRs are rock steady around 14.7 most of the time. Under load it richens up to about 10.0.

The only time that I have ever had issues with bucking were with boost leaks and loose vacuum lines before the AFC. Once I installed the AFC most of my bucking and soot issues disappeared. Tightening all of my vacuum lines and hose clamps eliminated all of the rest. Whenever the car starts running like ass, the first thing that I check are the hose clamps and the vacuum lines.

The other change which has proved beneficial has been moving the MAF to the pressure side, which makes the car less intolerant of boost leaks (at the price fo a slight loss of power).

Currently, the car is running like a champ. I'll have some dyno info for DSM once I have the MAM manifold installed.

R

 

[Puckpimp71]

I have the same problem... Just wondering if using the MIL eliminator for the O2 with the AFC could be part of the problem. When I dyno'd my car it appeared to still have the stock a/f curves...

 

[kicker22705]

Does the AFC clear the MAP if it loses power?

no. the afc has its own built in memory.

when i got mine dynotuned for 14psi, i asked him if it would revert the map to the supermap setting if i reset the ecu (disconnect battery), and he said it would go to the last saved map which was my 440cc 14psi map.