erratic idle

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mbred0609

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sup yall been a while since i had any problems but im back
so heres the deal.
92 mtx needs 60k badly but cant do for a month or so. so since winter is over its time to bring her back out and she ran fine before parked. my idle is very erratic. it idles mostly around 600 right now and when driving the rpms jump all over the place once it hits like 2-3k and the car bucks when this is ha[ppening. i have cleaned the MAF and have cleaned AND replaced the IAC with a known working one. none of this has helped. if i unplug the MAF or th IAC the car dies almost instantly. there is a little black box located on the throttle body that im not sure what it is but if i unplug it it does nothing. so im not sure if that is a problem or not. i havent had a chance to check codes yet but i will soon. and the CEL does come on alot of the time. i have also tried resetting the idle since the battery tooka sh*t over the winter when it sat. i have replaced the battery, although i know that has nothing to do with it i figured id let yall know anyway. now there is is one thing that may be a problem with the MAF that i should let yall know about. the first time i went to clean it i grabbed the wrong can (i grabbed the wd-40 can both cans were old and i didnt look closely enough like i should of.) so maybe the wd getting sprayed in there helped create the problem but i have used MAF cleaner after that and still nothing. i will make it to the junkyard sometime this week to get a new MAF but i wanted to ask yall first before i made that hour trip. any help will be appreciated. i have searched the forum many times and all i keep finding is clean MAF clean IAB clean IAC. where is the exact location of the IAB and i will try that next. thanks in advance and ill check back soon.
Matt. any questions yall have ill be sure to answer quickly.
 

mbred0609

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ok, sorry i didnt get back sooner but had to go ot of town for work and just back. first of all things got worse (a little). gas milage is down alot. tach is starting to read redline at like 4-4.5. the bucking has stopped. slight oil leak from accessory side. have the car on jackstands now looking for leak and replacing antenna and bad belt. the oil leak isnt that new but nows as good a time as any. also the one of the cats over heated to like cherry red yesterday and started smoking. just before that performance went downhill fast. barely made it home. pulling out was the worst. 0-10 in like 5 mins. once the rpms got up a bit and i was moving it was driveable. but stop and go was almost impossible. i got some codes for yall to.
KOEO:
111- system pass
116- ECT outside of test limits during either test
122- TP sensor circuit below minimum voltage
157- MAF sensor below minimum voltage
172- HEGO shows system always lean (rear)
212- loss of IDM input to ECA or SPOUT circuit grounded
214- cylinder identification circuit failure
542- fuel pump secondary curcuit failure: ECA to ground

KOER:
412- cannot control RPm during KOER high RPM check
116- ECT outside test limits during either test
136- HEGO shows system always lean (left)
172- HEGO shows system always lean (rear)
172- no HEGO switching indicates: lean (right)
172- no HEGO switching indicates: lean. i found 3 definitions in the book so i put them all
159- MAF sensor higher or lower during test

538- insufficient rpm change during KEOR dynamic response test

im going searching again now but incase i dont find anything helpful, the forum can always use another post with answers to go into the search archives. thanks, matt.
 

mbred0609

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ok hers the deal since last night. got up this morning and went back to work on the car. i have done the following
changed both o2 sensors with new
changed fuel filter
changed air filter
changed CID
changed TPS
cleaned MAF (dont have a spare but had a second motor to pull the CID and TPS)
still no luck finding the oil leak
put a piece of vacuum hose in my ear and moved around engine compartment to listen for vacuum leaks and i hear nothing out of the ordinary- also sprayed some starter fluid around and nothing
she still idles around 600
redlines around 3.5-4
had car go to 7k one time right after cleaning everything then pulled codes again and since the redline is off again
have cleared codes and the most recent pull gives me this
koeo:
111
111
koer:
172
136
dynamic:
2
6
help is apprecioated guys i ahve to go to work tomorrow and i need to get her running properly. i am working on other things as well so ill be working all day on her so i can check back regularly. please guys need some advice. done alot of searching to get wehre i am but i could use some real time help.
matt
 

mbred0609

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one more update: after a 10 min warmup to take one more code test afer cleaning MAF one more time i got a stored code on KOEO of 217 and the rest is the same.
 

mbred0609

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ok since last post i found 217 is most likely a DIS. i have changed out 3 different (that includes the original) and no change. i am wondering if the cat is clogged due to the redhot state on friday. i dont ahve access to another y-pipe right now will a simple cut and gut work for me until i can get a y? i do ahve access to the welder right now.
please someone i see people looking but noone has any advice
 

Rockledge

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What do you mean it redlines at 3.5-4K? What exactly happens at that rpm? Does a light come on? Which one?

A glowing cat can be caused by either a super rich or a super lean condition. Does the car blow smoke when it's bucking and jerking? Has it been running hot?

Have you actually tried another MAF?
 

mbred0609

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the rpm's will barely go above 4k and when it does it spits and sputters and wont go much higher that 4k.
the bucking and jerkiing had stopped over the past week or so. but it idled really low and the tach wouldnt go past 4.5k so i guess its not really a redline but the tach not reading properly.
no i havent had the opportunity to get another MAF, but the MAF codes cleared (unless the o2 codes can point me in teh direction of a MAF
other than that i have been trying the method as explained by projectsho89 in the thread 94 atx 3.2 dropping 2 cylinders. the voltage and all seem fine and i am chasing wiring right now i have found one bad connection and am charging the battery since i am replacing the A/C pump inbetween searches and looking for this problem and my alt is off. but that should be done in about an hour . looks like a late night and early morning.
 

SHOMON

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idle prob

it could be a chip if your car has one same thing happened to mine i pulled out the chip bam great
 

mbred0609

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just got my isp back so i figured id let you know. i followed projectsho89's guide in another post to check voltage and whatnot it was all good so i started tracing wires and found a bad section of wire it was all frayed and barely holding together on the backside of motor. so 2am i had all codes clear and by 4am had car back together, from the other work going on to. asleep by 4:30 back up at 5:30 for work. love those late nights.

but either way thank you projectsho89 i saw that stuff in your sig about search with your name and it took a long time but i got everything done by completely using the search engine. if i hadnt seen that id of given up looking a long time before. so thanks for being so helpful in the past that those of us in need now dont have to work so hard and wait so long to get help.

matt
 

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