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-   -   won't idle below 1,000 rpm, log attached (http://gnttype.org/forums/showthread.php?t=16268)

Scott Shillings 01-31-2013 12:27 AM

won't idle below 1,000 rpm, log attached
 
1 Attachment(s)
My son and I rebuilt the engine on '85 GN. It won't idle below 1,000 rpm in park, or in drive with the brake on at full stop. We've adjusted the IAC and TPS with scan tool per this forum, replaced all sensors, cleaned injectors, checked for vacuum leaks and fuel pressure, replaced coil and module, spark plugs and wires, etc. I've attached the TunerPro RT log. I started it several times after it dies, drove to the freeway and got to 85 mph.

kenmosher 01-31-2013 01:15 AM

Re: won't idle below 1,000 rpm, log attached
 
If its not in road mode, it'll idle at 1000. You scan tool could be holding it in ALDL mode.

Keller 01-31-2013 02:11 AM

Re: won't idle below 1,000 rpm, log attached
 
I'd say there is a 99.9% chance of Ken being correct.

A little tough to get some of the generic tools to work right in ROAD mode with our cars. Even the OTC scan tools (4000, anyway) required an undocumented trick to record in road mode. (Posted on the site.) You can't get good real world data (especially racing data) in 10K mode.

Scott Shillings 01-31-2013 09:44 AM

Re: won't idle below 1,000 rpm, log attached
 
I have the same idle problem without the scan tool connected. The log does say "Yes - ALDL Mode". Can someone look at my log attached to the original thread? (If you can't read the .xdl file, you can download the free scan tool software at www.tunerpro.net. For the definition file, I'm using 1D.adx for a 84-85 LM9 3.8L V6 Turbo 20 byte ALDL stream. The required 10K resistor is built into my ALDL cable.) I've noticed the PNP is always in Drive and my 02 sensor (I had it replaced) has a huge range at steady throttle regardless of the speed. The Rich / Lean is always changing too. The car is my 20 year old son's and I hope we don't need "racing" data at this stage of the restoration. Thank you for your help.

jlat 01-31-2013 07:46 PM

Re: won't idle below 1,000 rpm, log attached
 
hello; I know nothing about a HA car. I had a similar situation with my 86 but it just ended up to resetting everything. Educate me does a HA Buick have a throttle body? If so I'd ch it out for deposits and movement.
good luck
as with anything sometimes it just plain sucks
IBBY

kenmosher 01-31-2013 07:54 PM

Re: won't idle below 1,000 rpm, log attached
 
Yes, they have a "suck through" throttle body right on the turbo compressor inlet (vs. the "blow through" throttle body of the intercooled cars.)

I'm still betting on the scan tool is mucking it up ... pretty common.


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