Bad idle? Could it be missfire?

[nocturnalspirit]

ok so my 1st gen eclipse is idling realy weird ive messed with the biss screw and i have it at 3g's in neutral idle in drive it drops to 1-1.5g's well the problems is that even with the high rev my tach say is at 1.5 g in drive then it'll go up 1.7g's then it drops back to 1.5g's and it repeats slowly droping to 1g then it goes up and down like discribed then it drops to about 700rpm and dies....my friend thinks it might be missfire i think it might be a boost leak but i havent leak tested it yet cause i dont know how to make a tester + if its misfire i also wouldent know what to do....if any one has had this problem or herd of it any advice would be great thanks

 

[blcknspo0ln]

ok so my 1st gen eclipse is idling realy weird ive messed with the biss screw and i have it at 3g in nutral idle in drive it drops to 1-1.5g's well the problems is that even with the high rev my tach say is at 1.5 g then it'll go up 1.7g's then it drops back to 1.5g's and it repeats slowly droping to 1g then it goes up n down like discribed then it drops to 700rmp and dies....my friend thinks it might be missfire i think it might be a boost leak but i havent boost leak tested it yet cause i dont know how to make a tester + if its misfire i also dont know what to do....if any one has had this problem or herd of it any advice would be great thanks

It sounds like you are having issues with either your ISC or your ECU. 1g capacitors (in the ECU) are known to leak and cause problems like you are having. Do a quick research on "1g ECU) and you will get the information you need. Simply put, just pull your ECU and inspect the capacitors on it to make sure they're still OK. Chances are they're not.

 

[kottyking]

Is it idle SURGING? (The idle bouncing up and down)

 

[nocturnalspirit]

Is it idle SURGING? (The idle bouncing up and down)

i think that might be it cause thats what it dose and you can hear it in the exaust .....

i dont beleive its the ecu i had it checked and rebuilt like 4-5 months ago cause it blew on me and if it was the ecu i dont think the car would start and the tcu was also rebuilt so i know its not that either

 

[steve]

Part of it could very easily be a problem with the ECU or ISC.
Unless someone like myself or Dave Metz did the rebuilding I wouldn't bet on the quality of the work.

The simple fact that the car idles so high and drop when you put it in gear tells me that the ISC isn't functioning correctly. The high idle tells me that you have the problems with bypass air either from the BISS being misadjusted or leaks.

Steve

 

[nocturnalspirit]

Part of it could very easily be a problem with the ECU or ISC.
Unless someone like myself or Dave Metz did the rebuilding I wouldn't bet on the quality of the work.

The simple fact that the car idles so high and drop when you put it in gear tells me that the ISC isn't functioning correctly. The high idle tells me that you have the problems with bypass air either from the BISS being misadjusted or leaks.

Steve

exactly what is ISC???? ive herd that twice but i dont realy know what it is and if thats the case would you mind telling me how to find and fix the problem i would realy appreciate it.... the BISS was purposely adjusted high beacause we thought it would keep the car from dieing so much.... guess it wasnt the best idea.... this problem is soooo annoying and frustrating

 

[steve]

exactly what is ISC???? ive herd that twice but i dont realy know what it is

Let me give you a hint. When you have questions like this try searching or using some of the other resources available before asking. It's kind of like spelling things correctly, it shows respect that your willing to put in the effort in return for the help. I've heard that it goes a long way around here.

http://www.stealth316.com/2-isc-iac.htm

Steve

 

[nocturnalspirit]

Let me give you a hint. When you have questions like this try searching or using some of the other resources available before asking. It's kind of like spelling things correctly, it shows respect that your willing to put in the effort in return for the help. I've heard that it goes a long way around here.

http://www.stealth316.com/2-isc-iac.htm

Steve

thanks for the link and i appologise for the grammar errors and if i insulted or annoyed you i didnt think about it before i posted....... but now that i seen what the ISC is Ill check it although it was replaced recently and post if its defective thanks

 

[steve]

thanks for the link and i appologise for the grammar errors and if i insulted or annoyed you i didnt think about it before i posted.

I'm not annoyed or insulted but I guess I didn't get the point across.

We really do want people to capitalize, check their spelling as well as do their own homework as much as possible. Just about everything you can think of or run into has been discussed before. Searching may not give you the answer you were looking for but you'll learn all sorts of things that might save you a search in the future.

Steve

 

[unlmtdndeavor]

i'm having a very similar problem. i bought the car not running and i replaced a valve and placed the head back on the car. the car now will not idle. initially the biss was backed way out so the car would go right to 3k when i started the car then it would start to sputter and die out. we fixed the BISS and now the car sits at around 1200rpm. we were trying to adjust the CAS without too much success...we moved it towards the front of the car and it seemed to do a little better. at one point it surged pretty badly. the car has some old gas in it so that may be another problem. the ecu is good as i swapped it with one from my talon and the same thing happened. i thought the CAS would be out of phase so i turned it 180* and it didnt seem to help. any suggestions?

 

[nocturnalspirit]

i'm having a very similar problem. i bought the car not running and i replaced a valve and placed the head back on the car. the car now will not idle. initially the biss was backed way out so the car would go right to 3k when i started the car then it would start to sputter and die out. we fixed the BISS and now the car sits at around 1200rpm. we were trying to adjust the CAS without too much success...we moved it towards the front of the car and it seemed to do a little better. at one point it surged pretty badly. the car has some old gas in it so that may be another problem. the ecu is good as i swapped it with one from my talon and the same thing happened. i thought the CAS would be out of phase so i turned it 180* and it didnt seem to help. any suggestions?

my ecu is fine i ripped it out a week ago, i blocked of the egr because i read on v faq that it might help and it did a little but it still dies (but the car felt a little quicker) i bought an ohmeter and tested the isc and as i turned out it's broken .... unfortunately my transmission went out on me and im getting ready to do a a/t to manual swap and im not gonna worry about my idle untill i actualy get it to run again thanks for the help guys