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View Full Version : RPM drops the instant VSS is detected



ttls1
December 22nd, 2014, 02:18 PM
Hi, I have an issue with my car stumbling as soon as I start to move and it appears to be triggered by vehicle speed. I did a test by sitting on a hill with it idling in gear and holding it with the handbrake to eliminate brake vacuum. The instant the VSS went above 0 the TB dropped from 16% back to 11% and the engine nearly stalled. I did nothing but released the handbrake. Could this only be caused by the throttle cracker or could it be a number of things? any help would be greatly appreciated. I have attached a short log and my tune.

LQ4 TT 4l80e 235,235,114 cam

limited cv8r
December 24th, 2014, 12:11 AM
Try this, couple of small changes. Might help.

ttls1
December 24th, 2014, 01:20 PM
Thanks mate, I will give it a go. Cheers

joecar
January 15th, 2015, 11:11 AM
MAP pid shows that to much air is getting in.