High searching Idle

[jss06c6]

Originally Posted by Ccmano

At the risk of stating the obvious. You checked both MAP sensors, right?
H

?? Hose under the ECM ?

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[Ccmano]

Originally Posted by jss06c6

?? Hose under the ECM ?

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Yes, the other map sensor is under the ecm on the 90-92
H

[jss06c6]

Looked at it Hans. No issues. I'll recheck to make sure hose is good.

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[mike100]

well, since you have eliminated the outside hose connections, it sure sounds like the hard plastic curly-q under plenum hose has popped off. It goes to the gas tank purge solenoid. The leak is big enough to idle at 1200 rpm as you described. My car came like that and was the reason for my first plenum pull.

[jss06c6]

Originally Posted by mike100

well, since you have eliminated the outside hose connections, it sure sounds like the hard plastic curly-q under plenum hose has popped off. It goes to the gas tank purge solenoid. The leak is big enough to idle at 1200 rpm as you described. My car came like that and was the reason for my first plenum pull.

That's my guess too after reading Marc's summary of known offenders! Will know this afternoon when I get under there with my borescope..

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[jss06c6]

Found it.. unfortunately. Borescope clearly shows the hose on the curved pipe under the TPS going to the gas tank purge solenoid is off. Backfire must have blown it off. Will put hose clamps on these hoses when im in there this time.. happy I found it and glad it's not the TB. Well, needed to pull plenum and IH's to Port them anyway!

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[XfireZ51]

Originally Posted by jss06c6

... happy I found it and glad it's not the TB. Well, needed to pull plenum and IH's to Port them anyway!

The Lord works in mysterious ways.

[Ccmano]

Glad you found it, Had to be something related to the backfire. Unlikely the throttle body would go that suddenly.
H

[jss06c6]

Originally Posted by XfireZ51

The Lord works in mysterious ways.

Indeed!

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[jss06c6]

Originally Posted by Ccmano

Glad you found it, Had to be something related to the backfire. Unlikely the throttle body would go that suddenly.
H

More labor, but easier fix!!

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