1G throttle body BISS screw on 2G Talon

[carvinbassplyr]

Well the idle was fixed per the suggestions on here about backing the screw out so it only acts a stopper to keep the throttle plate from sticking. However, the car still shuts off if you have to stop fast at higher speeds. It's almost as if the car is going into complete fuel cut when the throttle closes instead of going back to a baseline idle speed? If I drive the car like a grandma it doesn't do it, but if I'm going through gears trying to merge onto an express way and someone cuts me off forcing me to take the car out of gear and slam on my breaks the car will just turn off. I replaced the Idle Control Motor that came in the 1G throttle body with the one out of the original body. I tested the pins before I installed it and the sensor checked out per the Ohms specs given in the manual. I'm really stumped on this one. I don't want to take it to a shop cause it's an automatic $100+ to do diagnostics anymore. Any ideas?

 

[gofer]

Do you have a wideband on the car to monitor AFR's when the car dies? That could help determine the problem whether it goes rich or lean.

 

[carvinbassplyr]

Do you have a wideband on the car to monitor AFR's when the car dies? That could help determine the problem whether it goes rich or lean.

I wish I did, but unfortunately the car is completely stock gauge-wise. There haven't really been any major mods to the car except for the updating of the drivetrain and the 1g throttle body install. I mean, I put a CAI on it and the 14b along w/the Hard Upper Intercooler Pipe & 3" turbo back exhaust came on the car.

 

[carvinbassplyr]

No one else w/any ideas/advice?

I thought of something today after reading posts of other people having problems at higher speeds. I put new spark plugs in the car and haven't put more than a couple hundred miles on them so I doubt they're fouled. However, the gap spec is a range and not a specific amt. If I remember right, I think I put it around .29-.30 (middle of the range). Should I try narrowing the gap to see if this helps my problem? Right now the car is on the stock BCS but I removed the restrictor so it's probably boosting a couple PSI more than stock. Also I went with the BPRES7 NKG plugs as those are readily available via the bike shops in my area. I know I'm not boosting high enough to warrant the cooler running plugs but I wanted to use something that I could buy locally at any given time. Would that cause this cut out when stopping fast at higher speeds?

 

[carvinbassplyr]

Regapped the plugs to .028 and while the car seems to run better, it still cuts out when I have to stop.@ higher speeds. I'm REALLY stumped on this one. I have to started to get a belt squeal when I start the car..thinking it's the alternator as the car's lights dim at idle and when the car tries to catch itself when I let off the gas. Dunno if a bad alternator would cause this kind of stalling problem at higher speeds...

 

[steve]

I assume that also means you don't have a datalogger so you can't tell if the BISS is correctly adjusted or if the ISC is actually working.

 

[carvinbassplyr]

I assume that also means you don't have a datalogger so you can't tell if the BISS is correctly adjusted or if the ISC is actually working.

You are correct. All these issues kind of put a kink in my upgrade path. I need this car to be a dependable DD above all else so until I can get this car running right I can't, in good conscience, blow money on tuning software and upgrades if I don't even know if I can drive the car.

 

[synthetek]

Did you just install the fidanza flywheel? or was it on before the TB swap?

 

[steve]

Did you just install the fidanza flywheel? or was it on before the TB swap?

I didn't look in his profile before but the lightweight flywheel would explain it dieing as described.

 

[carvinbassplyr]

I didn't look in his profile before but the lightweight flywheel would explain it dieing as described.

I must've missed something when it comes to light-weight flywheels. Why would this cause it to die? Obviously this isn't related to the idle issue?

 

[synthetek]

I think its because the RPMs drop faster with a lighter flywheel and the ISC cant compensate fast enough? I have seen the stalling issue on my cars and cars of people I know that have installed a lighter flywheel. I usually drive it for a few days and it goes away but if the ECU gets reset it starts stalling again. There are some ways to correct it with ecmlink too.

 

[carvinbassplyr]

I think its because the RPMs drop faster with a lighter flywheel and the ISC cant compensate fast enough? I have seen the stalling issue on my cars and cars of people I know that have installed a lighter flywheel. I usually drive it for a few days and it goes away but if the ECU gets reset it starts stalling again. There are some ways to correct it with ecmlink too.

I guess I missed that side note when taking suggestions for "things to do" while the tranny was out. Quite a few people recommended the lighter flywheel on here so I figured it would be a good upgrade, but no one mentioned the fairly common stalling problem it causes. The car is still having some intermittent idle issues so I will make sure to get those buttoned up before pursuing the correction/compensation for the lightened flywheel. I do feel somewhat lucky in the meantime to NOT be one of the people posting "Why does my car stall every time I press the clutch in?" since when the car is idling and I push the clutch in the rpms stay strong, dropping 100 rpms at the most if at all. So for now I don't have to be starring at the dreaded C word. If buttoning up the intermittent idle issues doesn't fix the stalling from the lighter flywheel however, my car is dead in the water without tuning software (which I can't afford )

 

[steve]

I think its because the RPMs drop faster with a lighter flywheel and the ISC cant compensate fast enough? I have seen the stalling issue on my cars and cars of people I know that have installed a lighter flywheel. I usually drive it for a few days and it goes away but if the ECU gets reset it starts stalling again. There are some ways to correct it with ecmlink too.

Correct, the way the software is set up the ECU doesn't catch the drop in RPM soon enough to keep the engine from stalling. If you have the problem you typically raise the RPM where the ECU turns the injectors back on during deceleration fuel cut.

There are still a few options before deciding it's caused by the flywheel and even if it is, now that we've fixed the high idle perhaps opening the butterfly a little more might help keep it from stalling. What RPM does the car idle at now?

Did you check the coils in the old ISC?

 

[carvinbassplyr]

Correct, the way the software is set up the ECU doesn't catch the drop in RPM soon enough to keep the engine from stalling. If you have the problem you typically raise the RPM where the ECU turns the injectors back on during deceleration fuel cut.

There are still a few options before deciding it's caused by the flywheel and even if it is, now that we've fixed the high idle perhaps opening the butterfly a little more might help keep it from stalling. What RPM does the car idle at now?

Did you check the coils in the old ISC?

Right now the car idles around the 800 mark. Yes I did check the coils b4 installing the 2g ISC and all were in spec. I'm still unsure if the BISS is set properly as I do not have the tools at my disposal to properly mess with the ISC and BISS screw.

UPDATE: Took the car out for a drive today after entertaining the idea that the flywheel might be what is causing this problem and after reading some threads on here about why lighter flywheels cause problems. I decided to change my tactics a bit and discovered that when I need to stop at higher speeds if I let of the gas first and start slowing the car down and then disengaging the clutch the car will not stall. As a matter of fact it reacts quite normal. I'm still going to take it to get a boost leak test and have the alternator checked out as I'm starting to get some pretty bad belt squeal when I start the car, but it looks like the stalling at high speed was because of a lack of knowledge on my part. I'll keep you posted if this starts to happen again or I run into any other issues. Thank you everyone for all the help!