383 is in!!! Idle Problems though.....
Thread Starter
Le Mans Master
Joined: Jan 2000
Posts: 6,595
Likes: 1
From: Thornton CO
383 is in!!! Idle Problems though.....
After not being able to driver my car for a month and a half, I have finally gotten the 383 in!!! :cool: Man does it sound good! Feels like it has some pretty good HP too.
I got everything all hooked up and it fired right up, just like it had been parked for 5 minutes but it seems to have some idle problems. It stalls quite frequently and it's an automatic. I played with the throttle position sensor and that seemed to help a little bit, but it still stalls occasionally. Any ideas on what the problem could be? Vacuum leak?
Any help would be appreciated.
I got everything all hooked up and it fired right up, just like it had been parked for 5 minutes but it seems to have some idle problems. It stalls quite frequently and it's an automatic. I played with the throttle position sensor and that seemed to help a little bit, but it still stalls occasionally. Any ideas on what the problem could be? Vacuum leak?
Any help would be appreciated.
Pro
Joined: Jun 2001
Posts: 697
Likes: 0
From: College Station Tx
Re: 383 is in!!! Idle Problems though..... (I_HATE_Mustangs)
Do you have a scan tool available? If so knowing what the
1) IAC motor stps
2) Idle timing
3) Idle pulsewidths
4) Idle MAP reading
5) Idle MAF reading
6) Idle O2/L-trims
are would be invaluable in diagnosing the problem.
If not I would first stick a vacuum guage and there and check it. You should be pulling ~ 17" or so at idle.
You might also try cleaning out the IAC hole on your TB.
Exhaust leaks and dead o2's can cause problems like this also - it's difficult to diagnose without some sensor readings though.
Thread Starter
Le Mans Master
Joined: Jan 2000
Posts: 6,595
Likes: 1
From: Thornton CO
Re: 383 is in!!! Idle Problems though..... (ChrisB)
I don't have a scan tool and my volt meter is dead too :( I am going to take the car over to the guy who built the motor and see if he can help.
The throttle body is a brand new BBK 58MM. There appears to be an idle adjustment screw/stop on it but there is no way to adjust it. I haven't checked the voltage of the TPS yet, but I'm guessing that could be part of the problem.
It just needs about 50 more RPM's to idle correctly.
Seems pretty fast though :D :D :D :D
The throttle body is a brand new BBK 58MM. There appears to be an idle adjustment screw/stop on it but there is no way to adjust it. I haven't checked the voltage of the TPS yet, but I'm guessing that could be part of the problem.
It just needs about 50 more RPM's to idle correctly.
Seems pretty fast though :D :D :D :D
Thread Starter
Le Mans Master
Joined: Jan 2000
Posts: 6,595
Likes: 1
From: Thornton CO
Re: 383 is in!!! Idle Problems though..... (I_HATE_Mustangs)
Oh Yeah, I almost forgot:
Thanks to Chris K. at Speed Demon Motorsports for his help with the valvetrain components! The GTP Cam seems to be pretty sweet!!
Thanks to Chris K. at Speed Demon Motorsports for his help with the valvetrain components! The GTP Cam seems to be pretty sweet!!
Pro
Joined: Jun 2001
Posts: 697
Likes: 0
From: College Station Tx
Re: 383 is in!!! Idle Problems though..... (I_HATE_Mustangs)
You can adjust the idle stop screw with an allen key. If you look on the backside of the boss that the screw sits in.
First thing I would try is simply opening this up a little - especially if you haven't adjusted it before. Try opening it while idling (just a bit at a time) untill the idle sounds better. You then need to key -off - key - on your car (powercycle) to re - zero the TPS. The TPS will re-zero from about 0.25 to 1v. If you open up the set screw more than that it will set a code. You can slot out your TPS sensor, but you shouldn't need to.
If the guy who built it has a scan tool you want to adjust the Set screw until the IAC motor steps are 30-40 at idle w/o A/C, and 80-100 with A/C. 0 is max close, and 160 is max open.
First thing I would try is simply opening this up a little - especially if you haven't adjusted it before. Try opening it while idling (just a bit at a time) untill the idle sounds better. You then need to key -off - key - on your car (powercycle) to re - zero the TPS. The TPS will re-zero from about 0.25 to 1v. If you open up the set screw more than that it will set a code. You can slot out your TPS sensor, but you shouldn't need to.
If the guy who built it has a scan tool you want to adjust the Set screw until the IAC motor steps are 30-40 at idle w/o A/C, and 80-100 with A/C. 0 is max close, and 160 is max open.
Safety Car
Joined: Dec 1999
Posts: 4,691
Likes: 1
From: Framingham MA
Re: 383 is in!!! Idle Problems though..... (I_HATE_Mustangs)
I don't have a scan tool and my volt meter is dead too :( I am going to take the car over to the guy who built the motor and see if he can help.
The throttle body is a brand new BBK 58MM. There appears to be an idle adjustment screw/stop on it but there is no way to adjust it. It just needs about 50 more RPM's to idle correctly.
The throttle body is a brand new BBK 58MM. There appears to be an idle adjustment screw/stop on it but there is no way to adjust it. It just needs about 50 more RPM's to idle correctly.
Safety Car
Joined: Mar 2000
Posts: 3,620
Likes: 2
From: Hillsboro OR
Re: 383 is in!!! Idle Problems though..... (I_HATE_Mustangs)
Idle is controlled by IAC and the computer. Fiddling with the throttle plates will just make the computer try to compensate for the extra air from the throttle plates. The throttle plates are supposed to be closed at idle. The correct way to fix this is to reprogram the ECM. Then the computer can correctly compensate for AC, deceleration, cold start etc. :hat
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