SAFC and idle surge question

[JcLovesLex]

i picked up a safc cheap i dont need it right now but i will soon enough.....now the questions....if i hook it up does it automatically read the computers settings ??? and my idle sometimes after driving basically like everyone else says on here its at stop lights etc.....i dont know to much about the throttle body and sensors and stuff so could someone explain better what to check and where it all is ???thank you

 

[JcLovesLex]

ok i replaced both sensors on the throttle body the tps i guess and the isc ..........still surging up and down after driving ...and now when i first start it the idle jumps up for like 10 seconds then gos to normal

 

[spdtuned]

It could be the idle air control valve, check the vfaq for instructions on checking/blocking it off

 

[DSMopar]

Check the simplest thing first, is your throttle cable sticking?

Failing that, FIAV... the cause of like 70% of idle problems...

 

[JcLovesLex]

throttle cable is fine ............. i put the new ics and the tps on and .....still surging...and now when it first starts the idle jumps up for 6 or 7 seconds then gos back to normal....i reset the computer and it is still doin it .......would i wanna block off the idle air control valve

 

[Lofty]

throttle cable is fine ............. i put the new ics and the tps on and .....still surging...and now when it first starts the idle jumps up for 6 or 7 seconds then gos back to normal....i reset the computer and it is still doin it .......would i wanna block off the idle air control valve

How high is it idling, you're being very vague, it's supposed to idle high when you first start it. That's it's Electronic Choke control. You don't want to block off your ISC. That's going to give you lots of issues. Loosen your throttle cable completely, I don't care if you say its fine, loosen it completely and then start the car, see how it idles. Do you have any vacuum leaks? Did you check the resistance of your ISC within the coils?

Check vfaq.com to see where all the sensors are.

 

[cjridert1]

These idles are tough to get right.
Did you set up your TPS correct (.63v @ closed)?
Idle switch is working/engaging? (+1 for what RPM 'high idle' is at)
I blocked off my FIAV and appropriate channels open for my IAC to still function fine. Nice since it eliminates one variable anyhow.
These TBs are pretty nice to work on, pull it off and replace the shaft and BISS O-rings, clean out some of that old carbon and set it up right.

 

[Maas]

FIAV block off

 

[PR_DSM]

i picked up a safc cheap i dont need it right now but i will soon enough.....now the questions....if i hook it up does it automatically read the computers settings ??? and my idle sometimes after driving basically like everyone else says on here its at stop lights etc.....i dont know to much about the throttle body and sensors and stuff so could someone explain better what to check and where it all is ???thank you

Witch SAFC do you have? Most will read it automaticlly the sensors you plug in, including karman and rpm.

 

[JcLovesLex]

im goin to try the throttle cable tomorow when i dont work .......how do u check the resistance of the isc within the coils ??what do you mean by idle switch ??how do you set the tps up correct i just bolted it up ............ i dont know to much about eletrical and sensors on these cars sorry ..........

 

[95talongirl]

Allthough I have never had to adjust a TPS when buying a new one.. these sensors are potentimeters, meaning that as the throttle plate opens (or closes), the sensor adjusts the voltage output (0 to 5 volts) to the computer knows what % the throttle plate is open. So, yah, they should be adjustable....

From my experience, I have found that most of my car's idle problems were from various vacuum and boost leaks. I would check for air leaks,like mentioned above.

 

[skatershawn]

From my experience, I have found that most of my car's idle problems were from various vacuum and boost leaks. I would check for air leaks,like mentioned above

Agreed.... i was having this SAME problem and replace all my sensors to find out it was a little leak in my throttle body area!!

First... my ISC did't have a gasket so i sealed that up...
Second my throttle body was missing the two bottom bolts... ( dont know how it was just rebuilt)
Third... my BISS screw was alllllll the way adjusted IN and STRIPPED!!!! fixed that!
and Last... well there were some small leaks i sealed up!

So i sealed up my isc, resealed my throttle body and replaced the bolts that where missing, replaced the BISS which was a "B" to get out, and BAM.... like a kitten she sounds! well with my exhaust it was more like a little cub lion!!

good luck man!!

 

[kamronman]

HEY MAN! you have a vacuum leak! My car does the EXACT same thing ok! I have a datalogger, and i've finally figured it out. With the isc plugged in and operating properly, when you're rolling up to a stop(open loop) its going to surge(isc) to compensate for the loss of vacuum from the leak! Once you're at a dead stop i bet the surge goes away(closed loop) and your idle is funky, go under the hood and unplug a vac line while it's warmed up, you'll find out the funky idle just gets worse!

Hope i helped, my vac leak is on an injector seal, so i'm replacing them all when i upgrade injectors!