Interesting problem. Tuned?

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11-15-2008, 11:04 PM

#11

rygi23

4th Gear Member

Join Date: Dec 2007

Location: Maryland

Posts: 1,503

Quote:

Originally Posted by grif62

I though the problem would be the air to fuel ratio, but im a little off. But if it was u can play with it on ur tuner and fix the problem

Have a predator. Only adjustment in it for A/F ratio (that I know of anyway) is under "Modify Parameters" called "Fuel WOT". Separate adjustments for 2k-4k and 4k-7k. Wouldn't help the problem we're addressing in this thread though. Just had a thought as I'm typing this though. If the problem is persistent enough, maybe setting the idle rpm a couple hundred higher would help it. Just a thought, haven't tried it.

11-16-2008, 10:24 AM

#12

Shaken

1st Gear Member

Join Date: Sep 2007

Location: Michigan

Posts: 128

Since I have incorporated my screen into my K&N CAI I have had zero problems with the dropping RPM issue. I have also received a few custom tunes from Diablo and each one the RPM's where higher than factory 770 if I remember right. Also you might what to see if you MAF is clocked at 11 o' clock some have stated this helped them with the JLT RAI. It seems to me it is not so much turbulence than the lost of signal when lifting off the gas pedal. The air filter itself is more restrictive where the media comes together you might try making sure the seam is at 5 o'clock. It also seems that the manual trans cars are more sensitive to this RPM issue so another suggestion would be to apply the clutch when coming to a stop an not before so you are not coasting. As far as checking your TPS (throttle position sensor) voltage a hand held tuner will read that or you will need a digital volt meter to measure the voltage at the TPS. Our TPS has very little adjust ability.
Car off key on loosen the hold down screws and twist it and re tighten when proper voltage is reached below 1 volt. It has been said closer to .090 volts.

Last edited by Shaken; 11-16-2008 at 10:34 AM.

11-17-2008, 03:52 PM

#13

R-code17815

1st Gear Member

Join Date: Oct 2008

Location: Pennsylvania

Posts: 61

TPS = Throttle position sensor, located on the throttle body. If I remember correctly It's the top 2 of 3 wires. easiest way to check is poke a straight pin thru the wires and with the key on engine off use a voltmeter to set the voltage to .97-.99.

IAC = Idle air control valve, located behind the TPS. These are know to be junk and cause trouble, high idle, hanging idle, stalling etc. I reccomend installing a IAC restrictor to help with this (E-Bay or M1R), there about 10-15 bucks, and if you decide to replace the IAC use a Motorcraft replacement, cheapies are junk.