Engine idle/take off issues, help solve
10-21-2006, 09:29 PM
#1
Engine idle/take off issues, help solve
Heres what it does.
I'm backing up, when I stop or right when I put it into D it acts as if its about to stall but it doesn't. It sits there sometimes for 10-15 seconds and struggles to stay alive. Like an old car that wont turn off after you remove the key.
The vacuum gauge goes from 20 to 0 in about 2 seconds and the fuel pressure goes up about 8-10psi and the AFR goes from 14.7 to 28 or 30. It just shakes until I either give it some gas or it catches itself. This will also happen sometimes if I pull up to a stop sign and then got to take off again. It sputters for a second and then (because I have put the pedal at 50%) I take off like I'm launching for a run at the track.
Clogged injector or something? I wouldn't think fuel pump issue since the pressure in the rail increases when this is going on. And since the AFR goes up, I'm thinking an injector (or all) need cleaned???
Will EFI Live do an injector balance test?
I'm backing up, when I stop or right when I put it into D it acts as if its about to stall but it doesn't. It sits there sometimes for 10-15 seconds and struggles to stay alive. Like an old car that wont turn off after you remove the key.
The vacuum gauge goes from 20 to 0 in about 2 seconds and the fuel pressure goes up about 8-10psi and the AFR goes from 14.7 to 28 or 30. It just shakes until I either give it some gas or it catches itself. This will also happen sometimes if I pull up to a stop sign and then got to take off again. It sputters for a second and then (because I have put the pedal at 50%) I take off like I'm launching for a run at the track.
Clogged injector or something? I wouldn't think fuel pump issue since the pressure in the rail increases when this is going on. And since the AFR goes up, I'm thinking an injector (or all) need cleaned???
Will EFI Live do an injector balance test?
10-21-2006, 10:18 PM
#4
Still waiting for a fix for EFILive's Bidirectional Controls> "Cylinder Balance Test." Maybe it will work if you are non-ETC.
Are you running off the MAF or SD? Have you changed any of the idle/airflow tables recently? Recent mechanical changes? Have you allowed time for idle learn since your last reflash? Is idle learn still enabled in the tune? Idle learn will compensate if your tables are off a little or there is a minor vac leak, etc. ECT has to reach the enable temp(B4501) before idle learn becomes active. If ETC, is B4349 correct? If not ETC, is the IAC motor functioning properly? Could the TB be sticking?
Are you running off the MAF or SD? Have you changed any of the idle/airflow tables recently? Recent mechanical changes? Have you allowed time for idle learn since your last reflash? Is idle learn still enabled in the tune? Idle learn will compensate if your tables are off a little or there is a minor vac leak, etc. ECT has to reach the enable temp(B4501) before idle learn becomes active. If ETC, is B4349 correct? If not ETC, is the IAC motor functioning properly? Could the TB be sticking?
10-21-2006, 10:30 PM
#6
Originally Posted by DrX
Still waiting for a fix for EFILive's Bidirectional Controls> "Cylinder Balance Test." Maybe it will work if you are non-ETC.
MAF
No
Nope
Habent touched the tune in months
I dunno
Idle learn will compensate if your tables are off a little or there is a minor vac leak, etc. ECT has to reach the enable temp(B4501) before idle learn becomes active.
0.0
I am ETC
I dunno, doesnt do it all the time so I would guess no.
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Are you running off the MAF or SD?
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Have you changed any of the idle/airflow tables recently?
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Recent mechanical changes?
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Have you allowed time for idle learn since your last reflash?
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Is idle learn still enabled in the tune?
Idle learn will compensate if your tables are off a little or there is a minor vac leak, etc. ECT has to reach the enable temp(B4501) before idle learn becomes active.
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If ETC, is B4349 correct?
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If not ETC, is the IAC motor functioning properly?
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Could the TB be sticking?
10-21-2006, 10:32 PM
#7
Originally Posted by KySilverado
Have you had the battery unhooked for anything recently? Mine runs like that after I work on it, unhook the battery. Takes awhile for it to "learn" idle again.
Nothing that I can think of triggered this behavior. It has kind of just always been that way since my last dyno tune/cam swap. It idles like
with the AC on in park as well, blows hot. I've checked all those tables and they seem ok. While driving the AC is ice.
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10-21-2006, 10:54 PM
#9
B4501 sounds OK(still stock).
You will have to expand the number of decimal places to see what B4349 is set to.
Which TB do you have on there? My 90mm was sticking a little and I had to loosen up the screws on the plate, make sure it moved freely and re-tighten. I have similar idle issues with the 90mm when ambient temps get to freezing and below. Starts up OK, put it in D or R and it stumbles or dies unless I give it a little throttle as I shift to keep it running and give it a chance to learn. Still working on that. Wasn't an issue all summer. Probably part of the 90mm calibration issues that still aren't worked out.
I'll take a peek at your tune as a second set of eyes if you like. PM'd you my email.
You will have to expand the number of decimal places to see what B4349 is set to.
Which TB do you have on there? My 90mm was sticking a little and I had to loosen up the screws on the plate, make sure it moved freely and re-tighten. I have similar idle issues with the 90mm when ambient temps get to freezing and below. Starts up OK, put it in D or R and it stumbles or dies unless I give it a little throttle as I shift to keep it running and give it a chance to learn. Still working on that. Wasn't an issue all summer. Probably part of the 90mm calibration issues that still aren't worked out.
I'll take a peek at your tune as a second set of eyes if you like. PM'd you my email.
10-21-2006, 11:46 PM
#10
Originally Posted by DrX
B4501 sounds OK(still stock).
You will have to expand the number of decimal places to see what B4349 is set to.
Which TB do you have on there? My 90mm was sticking a little and I had to loosen up the screws on the plate, make sure it moved freely and re-tighten. I have similar idle issues with the 90mm when ambient temps get to freezing and below. Starts up OK, put it in D or R and it stumbles or dies unless I give it a little throttle as I shift to keep it running and give it a chance to learn. Still working on that. Wasn't an issue all summer. Probably part of the 90mm calibration issues that still aren't worked out.
I'll take a peek at your tune as a second set of eyes if you like. PM'd you my email.
You will have to expand the number of decimal places to see what B4349 is set to.
Which TB do you have on there? My 90mm was sticking a little and I had to loosen up the screws on the plate, make sure it moved freely and re-tighten. I have similar idle issues with the 90mm when ambient temps get to freezing and below. Starts up OK, put it in D or R and it stumbles or dies unless I give it a little throttle as I shift to keep it running and give it a chance to learn. Still working on that. Wasn't an issue all summer. Probably part of the 90mm calibration issues that still aren't worked out.
I'll take a peek at your tune as a second set of eyes if you like. PM'd you my email.
I have the stock TB on the radix. It is DBW. I'd say 90% of the time its not an issue. But it did it one time as I was pulling into traffic and it scared the crap out of me.