i smell lean at idle,A/Fmeter shows it too..

[KeithL322]

Ok so heres the deal... I start my car.. and I can SMELL it running lean at idle my a/f gauge shows it too... then it will slowl climb into stoich.. .i know the 02 sensor has to come up to temp to read correctly... so heres where it gets weird...if i fiddle with the gas then let it idle again once its at temp, it will register stoich for a sec, then go all the way down into lean, and then off the a/f lights further lean...and my vac is supose to be at 20... but most the time it is at about 17... but it fluxuates between 20and 16 alot... ok. next part...my idle...when the car is running well is at about 1100..high i know... but i have to set it that high because when the vac goes up to 17 or so the idle will drop to about 700-750...first thing i thought was boost leak, but that would make me run rich, which im not...so i dont have any clue what it can be, oh and also, anytime i turn on ANY accesory, lights, or heat the vac will drop even more and my car idle will drop even more and stay there and all of my gauges and lights inside will get dimmer.. when i give it gas and its not at idle its fine...only thing I could possibly think of is Im running off the 02 sensor housing atmcause my downpipe came off of it somehow, i already got a new gasket and the bolts for it though, does anyone have any clue what else it could be??
thanks for all help in advance

 

[kspharris]

Your A/F gauge is going to be all over the place at idle. The idle on 1g's are supposed to be set between 750-850, if memory serves. When your mess with the idle after it warms up and it goes "off the chart" that is the ECU cutting fuel for the rpm's to fall (your car does not need gas when the RPM's fall). A healthy motor will read between 16-20 on the vac side of your gauge. As far as your accessories go that sounds about right for 1g's. You could have your alternator checked out, check your belt and tighten it if needed. Is your car a manual? You can use a automatic alternator and it should keep your lights steady at idle, at least it did for me. You need to block off your EGR or put it back on. I would also check all your emissions crap as you call it and make sure that there is nothing wrong there. Take a look at all your vacuum lines as well. Hope this helps and welcome to the DSM world, Keith.

 

[jbouvier]

...its not my ECU cutting fuel.. i know what that is like, my isc motor was bad seeing as one of my coils ohm readings were like 300... and its supposed to be like 34 max... thats why i never posted this yet, is because i didnt know if it was my isc causing this as well, because before i would either have idle surge, or my idle would be at like 500... and then RARELY it would be correct and sit at 750...but since then i have replaced the ISC, no more idle surge... now it just fluxuates between running normal, and idling low, i am POSITIVE its not the motor cutting fuel... o and i also forgot to mention... when im in neutral and the car is not idling correctly... if i give it gas and hold it at like 1300, it will sound normal for the most part except about once a second it will kind of cut out for a sec...i have suspected it possibibly being the egr valve not blocked off, as i dont know how that would make the car run, but I cant find a how to diagram for how to install the egr block off plate, seeing as i dont know exactly where the valve is.. the diagram on the free mods page is broken... instead of that the only thing i can think of is my alternator might be weak, especially seeing as the 02housing dumps all the exhaust right there beside it...I would like to resolve the simpler problems first, like blocking the EGR valve, and then jsut plugging the rest of the emissions lines..

 

[KeithL322]

sorry my friend logged in and i didnt know it, so i was under his name, so the post by jbouvier is me...

 

[KeithL322]

and when i give it gas to get it out of idle, the RPM's actually drop for a second, and then climb like they should be seeing as im giving it throttle...

 

[KeithL322]

and not trying to be an ahole or nothing kspharris, thats not normal for the accessories, when your ISC is working properly its supposed to compensate when you turn on you lights or blower motor etc... the vac isnt supposed to jsut drop.. it will drop for a second when you jsut turn them on, and should then go back to normal(20) after the ISC adjusts...

 

[kspharris]

You are right about it dropping for a sec and then going back to normal but yours is not right? That could mean the stuff that I mentioned about tightening the belt, checking the alternator, etc...could be at fault. Just to clear the ECU fuel cut I was talking about, when the motor is under deceleration the ECU turns the fuel off. It also does it when the rpm's are falling when the motor is revved. It is there to save fuel. From what I understand from the first post where you stated that the lights go further down after you fiddle with the idle. This sounds to me like what I am talking about. You may want to check you throttle cable for the rpm's dropping for a sec before they start to climb, there may be slack. You know it might be that when your rpm's are fluctuating that your fans are kicking on and off. If your alternator is going out then when the fans kick on it might cause it to fluctuate. I hope that I have been some help and I know your not trying to be a jerk so don't worry about that. Thanks, Keith.

 

[KeithL322]

no problem man, and once again thanks for all your help as an update i just reconnected the o2 sensor housign to the downpipe and put a new gasket in... although it is still leaking a tad(already put a gasket from autozone on there and used the old nuts, and it leaked like crazy..until it came undone!...bought this gasket from dealer and got new nuts to strap it down, leaks just a little now) i had a oil leak on my oil feed line that i jsut got done fixing (hopefully) as well, there is a small like of oil on the outside now once i started the car again, but it doesnt look like its actualy leaking any, ill just have to drive it a little and see.. bu tanyways back to the car... i actually satarted it again before i put the 02 housing on, and this time it smellt rich! i went to look at a/f gauge and it was sitting in the middle of the rich section, and rpms were correct...shut it off... started it back up about 20 seconds later.. . af gauge back to lean and rpms low again... i really am starting to think it is my alternator!.. are those things a pain to take off and put back on? never changed anything that has a belt strapped to it yet! (ei. alternator, power steering, ac compressor, water pump! :/ )

 

[KeithL322]

and i understand what you rsaying now abou tth eecu cutting the fuel!.. but doesnt the ecu cut the fuel completely when rpms are dropping or motor is revving down??

 

[kspharris]

Yes it does cut the fuel completly when it is revving down but has to jump back up to catch itself. Do you disconnect the battery every time you are working on the car? If you do then your ECU will not be back to normal yet, I think it is recommended to drive it for 15 minutes before it learnes your driving style. Don't quote me on that one yet because I do not have my 1g manual here. Alternators are pretty easy, there is a tension bolt, just loosen it and release the belt. Then there are two bolts and a couple of electrical connectors(don't forget to disconnect the battery for this one) and you are done. Let me know if you have any more questions, Keith.