Thread: idle issues.

Car surges at idle only. Doesent seem to be a real pattern with this but i do notice it a lot more when the engine is cold rather than warm. This just started not long ago and cant remember doing anything to my tune before it started. The engine will surge in small amounts lets say from maybe 600-1000 then will slowly climb to like 600-1500 then eventually just kill. starts right back up and pretty mucch does the same thing.



Give it a little gas and hold it it is fine. Also when it's doing it it is only in neatural. As soon as i put it in drive or reverse it stops.Another thing i noticed was when driving and comming to a stop the rpms surge up maybe around 400 or 500 rpm's and the car jumps foward a little and then everything is fine. Going to check the iac now. And just for kicks i adjusted the idle to 850 across the board so i could rule that out. Trims are out of wack but have been way worse with no problems. Working on that also.



Ideas?



Mod list in sig.

you know i read something about that the other day. I'm probably comanding a 14.7 A/F wich i read was to rich. He said he lowered it to a 10.0 or something like that and everything was good. I dont have a wideband so you got any tips or suggestions? What did you do?

Oh well mine was stock anyway. never messed with it to begin with. Have any other ideas? It was doing it again today, and the engine was nice and warmed up.

Originally Posted by IndeedSS

fwiw 10.0:1 is a LOT more rich than 14.7:1

Sorry,it was at 10.0 and he raised it to 15 or so.

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This is the problem to see for yourself exactly what is happening. Now what i did was also log IAC Position and IAC desired rpm. I just placed the two gauges right on top of the other ones so sorry if it is hard to see. The bottom line is the iac does not seem to be the culprit. They are on the bottom of the rpm gauge if for some reason you cant find them. Thanks for any additional help

Dont know if this is normal or noy but im just trying to trouble shoot things....



When the Vac line to FPR is disconected the car wont run pretty much at all...



When the MAF is unplugged the car surges and I cant tell any difference in how it runns at idle and when reving it up in park or neutral.seems the exact same.


Iat(im trying anything) same....



IAC- when i unplug it the car revs to aout 3000 rpm's and just sits there...maybe slowly climbing at times

As you can see in this screen shot the car is surging...will a second set of eyes look this over and see if something abnormal is there. Not sure if this is tune related or not.

the scan above was with the car in gear. Take it out of gear and it would have been surging till about 3000 rpm's and eventually kill.....

And i imagine that the timing is bounicing around like that because of the fluctualtions in the rpm's. When im driving it does not surge and the timing stays put.I understand what your saying though. kinda hard to diagnoise becuase if this is a sensor or a componet that is displayed and it is fluctuating like that it is making everything fluctuate thus making the problem hard to find. And as far as the map goes i adjusted it to where it is just barley touching the set screw on the s/c. Ithought that may have been some of my problem since it apeared i was getting boost at idle.... so i elive it would have been higher than yours a cupple days ago

May have figured this out. will post up later tonight.

Well After my exhaust fell off while driving, I went back home and re-attached the Y-pipe to the rear header and crossover once again. This time it made a little better seal than it did last time....but is STILL leaking pretty bad. Anyway after this the surging stopped. It was Leaking pretty bad before also. I mean I cant belive it was something that simple yet I went through hell trying to find it. I mean I unplugged almost every sensor that the car has on it,even the O2 sensor trying to trouble shoot this problem....o well....I knew the surging had gotten worse so i was trying to think of parts or other problems that had gotten worse also. Those two things were spark plugs and the leaking exhaust....



So i guess this problem like many others was kind of like ''Where's waldo''....You look for ever and when you finially find his ass he was right in front of you the whole time.




I cant belive I Over looked my biggest on going problem that i've had with the car while trying to trouble shoot this new problem.




So thanks again for all of the help and suggestions.

Glad to see you gat that problem fixed. Was the other the starter?

yup