LS1 high idle= vacuum leak?
08-13-2012, 10:06 AM
#1
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LS1 high idle= vacuum leak? I'm using an LS1 form my conversion.
Motor has an LS6 intake. I'm using a stand-alone aftermarket (painless) ecu tuned to a mild cam. The ecu uses the MAP sensor.
This motor has been run for a total of maybe 10 minutes and has not seen the road. Motor starts right up and idles at 2000 rpm initially, then settles at about 1800. If I cover the hole in the throttle plate it settles to about 1200. The idle should settle down to 800 right?
Things I've tried:
- checked the IAC valve and replaced it with a spare
- replaced tb with a spare
- replaced pcv valve *THE MOTOR IDLED FINE FOR A BIT WHEN I DID THIS*
- checked for leaks at the tb at all unused inlets.
- blocked off the inlet to the tb for the pcv to isolate that as a problem.
- blocked off the hole in the tb plate
- checked the back of the intake for leaks.
- adjusted the throttle screw to proper voltage
Am I missing something? Is there any way to check the MAP sensor besides replacing it with a new one?
Motor has an LS6 intake. I'm using a stand-alone aftermarket (painless) ecu tuned to a mild cam. The ecu uses the MAP sensor.
This motor has been run for a total of maybe 10 minutes and has not seen the road. Motor starts right up and idles at 2000 rpm initially, then settles at about 1800. If I cover the hole in the throttle plate it settles to about 1200. The idle should settle down to 800 right?
Things I've tried:
- checked the IAC valve and replaced it with a spare
- replaced tb with a spare
- replaced pcv valve *THE MOTOR IDLED FINE FOR A BIT WHEN I DID THIS*
- checked for leaks at the tb at all unused inlets.
- blocked off the inlet to the tb for the pcv to isolate that as a problem.
- blocked off the hole in the tb plate
- checked the back of the intake for leaks.
- adjusted the throttle screw to proper voltage
Am I missing something? Is there any way to check the MAP sensor besides replacing it with a new one?
08-13-2012, 11:52 AM
#2
Have you scanned the engine while running? What are IAC counts, what is map reading?
When you say that the ECU uses a MAP sensor, is it set up for speed density? Do you have a MAF sensor hooked up?
Jon
PSI
When you say that the ECU uses a MAP sensor, is it set up for speed density? Do you have a MAF sensor hooked up?
Jon
PSI
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www.psiconversion.com
Ebay Store
Facebook/psiconversion
Instagram/psiconversion
'Dont Let EFI Pass You By!'
10-03-2020, 05:19 PM
#7
Necro bump..... but this helped my issue....... LS1 came back from tuner with 2000rpm idle on decel.... until o mph.
Did smoke test on intake...... the back pcv hoses were seperated...... must of happened at the tuner.
Re-attached... idle back to normal. High-idle check for vac leaks.
Did smoke test on intake...... the back pcv hoses were seperated...... must of happened at the tuner.
Re-attached... idle back to normal. High-idle check for vac leaks.
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