The car is running well but the idle has begun to bounce if the vent fan is turned on. If the a/c is on the idle rises as expected (so the BAC is functioning) and doesnt seem to have an observable bounce. If the vent fan and a/c are off, the idle is flat and even.

The TPS is new (from Malloy) and is currently reading when hot 1.16v at idle and 4.73v at WOT per the Zeitronix.

I believe the TPS setting is in the acceptable range so wanted to see if folks had suggestions on where to look for vacuum leaks.

Thx.

 

Tweak the TPS setting some and see if the bounce stops.

 

Thanks, Satch. I put the TMIC bypass on and got the TPS at idle to 1.02v. That didnt work so I sprayed some ether on the intake track and I think we have something near the BOV valve. I suspect the rock hard rubber elbow that feeds the BOV so we're gonna cap it off and see.

Thx

 

What is the alternator output when this occurs. Measured at the battery + terminal and measured at the output post on the alt?

 

IDK. I'll check both places tomorrow.

 

13.97 at the alternator lug and 13.92 at the positive terminal on the battery.

I replaced the BOV (well, BPV) with some 5/8" silicone hose and plugged the BPV vacuum line but as soon as it warmed up it started bouncing.

Are the OEM charge pipes vulnerable to leaking?

 

What does the idle speed do w/the fan on as far as it dropping if any? Does the idle bounce regardless of what setting the fan speed is at? You might want to check pin 3O at the ECU w/key to on and the fan off and w/the fan on. Should read 12 volts w/the fan off and 2 volts w/the fan on as well. And you might want to test the voltage on the Blue/Green wire at the BAC w/the idle bouncing w/the fan on and compare it to the reading w/the fan off. Also, check this same wire for voltage w/the A/C on and A/C off.

 

The charge pipe nipple to the BAC broke off when I was taking it off. I assume I can temporarily patch the hole in the charge pipe and then put a solid gasket behind the BAC as a "block off" until the Corksport charge pipe arrives. Then I can do Satch's tests.