Surging @ Idle
Re: Surging @ Idle need more info..
does it do this on cold starts? warm starts?
log your IAC counts at idle. They should be in the 20-40range when the car is warm. Addin timing at idle helps a little also, but its probably where you arent getting enough air with the cam
does it do this on cold starts? warm starts?
log your IAC counts at idle. They should be in the 20-40range when the car is warm. Addin timing at idle helps a little also, but its probably where you arent getting enough air with the cam
Re: Surging @ Idle Only on cold starts...my IAC counts drop down to 1 when the car is fully warmed. If I made the
TB hole any smaller though the car barely starts up (cold). I think it really needs more air, but my '98 can't adjust the IAC Park Position.
TB hole any smaller though the car barely starts up (cold). I think it really needs more air, but my '98 can't adjust the IAC Park Position.
Re: Surging @ Idle have you tried to add any timing at idle??
go to the base park in park table and add a few degrees in the 0-1200 cells down to .2 only and see if that helps any..I have mine set around 23degrees at idle with my 224 cam
my cold start fire right up, but it just surges after like 20seconds i guess trying to find idle. But i hear alot of cars do that when they are first warming up from bigger cams.
My IAC hovers around 0-10 in this cool air, use to be 20ish. Mine does stall from time to time on warm starts also.
another thing, whats your idle at?
go to the base park in park table and add a few degrees in the 0-1200 cells down to .2 only and see if that helps any..I have mine set around 23degrees at idle with my 224 cam
my cold start fire right up, but it just surges after like 20seconds i guess trying to find idle. But i hear alot of cars do that when they are first warming up from bigger cams.
My IAC hovers around 0-10 in this cool air, use to be 20ish. Mine does stall from time to time on warm starts also.
another thing, whats your idle at?
TECH Fanatic
Joined: Nov 2001
Posts: 1,355
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From: Chicago (Elgin), IL
Re: Surging @ Idle IAC control counts as previously said should be between 20-40 at idle consistently.
Do a couple quick snap throttle to 3,500rpm and watch the idle air count. After each rev to 3,500rpm, it should gradually come back to within 5-10 counts of where it had been at idle.
If it doesn't, your IAC motor is bad.
Have you looked at your MAP sensor?
Perhaps you are also getting a low HO2S voltage reading which will not allow the PCM to maintain a base idle. This is/is similar to a P0131 code.
Do a couple quick snap throttle to 3,500rpm and watch the idle air count. After each rev to 3,500rpm, it should gradually come back to within 5-10 counts of where it had been at idle.
If it doesn't, your IAC motor is bad.
Have you looked at your MAP sensor?
Perhaps you are also getting a low HO2S voltage reading which will not allow the PCM to maintain a base idle. This is/is similar to a P0131 code.
Re: Surging @ Idle I will try to add timing, but last time I added it (to all rows in the first 4 columns) it made it worse. We shall see...
I am getting a O2 sensor error but that's because I yanked the rear O2 sensors off so right now nothing is connected. Would that make the differenece? The front O2 sensors are still operational.
I am getting a O2 sensor error but that's because I yanked the rear O2 sensors off so right now nothing is connected. Would that make the differenece? The front O2 sensors are still operational.
Re: Surging @ Idle </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by bomax182:
<strong> I am getting a O2 sensor error but that's because I yanked the rear O2 sensors off so right now nothing is connected. Would that make the differenece? The front O2 sensors are still operational. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">nope...the rear O2s are only for testing the cats. The front ones are all that you need to be concerned with.
<strong> I am getting a O2 sensor error but that's because I yanked the rear O2 sensors off so right now nothing is connected. Would that make the differenece? The front O2 sensors are still operational. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">nope...the rear O2s are only for testing the cats. The front ones are all that you need to be concerned with.
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