# idle problems after intake install....



## gaijin_resa (Jun 18, 2005)

I put a short intake on my Sentra and now it won't idle until the temp gauge is up about halfway. Needless to say it makes even pulling out of the driveway an adventure. As fun as that is, is there any way that I can get it to idle. I have the stock maf still. I also turned up the idle screw. Any suggestions. This install also threw a service engine light.


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## WiZzO (Jun 15, 2005)

what do you mean it doesnt idle? is it to high or low or what? and just an idea, check out your MAF sensor, if you dropped it on the ground by accident or something you might have broken it...this would also throw on a check engine light. try to disconnect it and see what happens.


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## gaijin_resa (Jun 18, 2005)

WiZzO said:


> what do you mean it doesnt idle? is it to high or low or what? and just an idea, check out your MAF sensor, if you dropped it on the ground by accident or something you might have broken it...this would also throw on a check engine light. try to disconnect it and see what happens.


I did try to run it without the maf sensor connected. When that happened the engine, when I pressed the acclerator, revved up and down real fast. I am fairly certain that I didn't break it because I went back to stock to get a new clutch put in. Now I put the intake back on and it just idles down until it dies.


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## Hendrix (Jan 17, 2004)

after installing my intake I had to reset the ECU, then the engine ran with no problems.


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## gaijin_resa (Jun 18, 2005)

Slow_Sentra322 said:


> after installing my intake I had to reset the ECU, then the engine ran with no problems.


How do I do that?


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## WiZzO (Jun 15, 2005)

take the negative cable off the battery for a few minutes put it back on and turn it on, i'm pretty sure that resets it


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## likemynuts (Apr 2, 2004)

Hey, check this out. When I installed my cai. I accidently put the filter up too far on the piping. the motor couldnt get enough air and kept killing at idle. Check that out before u try anything else. I just pulled my filter off the pipe a little more and it runs perfect


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## gaijin_resa (Jun 18, 2005)

I will try these suggestions, my stepdad thinks that it is because I don't have a "High-Flow MAF" which I have never heard of before now. I was looking at other intakes on the net and I did notice one difference, most other intakes require some kind of filter oil. I did not recieve any instructions with my intake nor did I recieve filter oil, could this cause that kind of a problem?


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## Captain Obvious (Jan 2, 2004)

gaijin_resa said:


> I will try these suggestions, my stepdad thinks that it is because I don't have a "High-Flow MAF" which I have never heard of before now. I was looking at other intakes on the net and I did notice one difference, most other intakes require some kind of filter oil. I did not recieve any instructions with my intake nor did I recieve filter oil, could this cause that kind of a problem?


dont need "high flow maf" and dont realy need oil either the oil just traps the dirt a lil better

try lookin for pinched/kinked vacum lines, try the filter thing look at the couplers that you tightened down make sure there on right and the clamps are on the tubing and not between blocking air flow.
also where did you put the temp sensor it was on top of the air box and when you put the intake on theres no hole for it you said that it has rough idle till its up to operating temp {gauge in the middle} so mabye you have that temp sensor in a bad place of you killed it by banging it round or somthin

my temp sensor was zip tied to the tubing right below the filter so its in close proximaty to the air flow 

but ya check everything you can first loosen retighten make sure it looks right based on pics you find on the net theres tons

and then you may have to buy a couple sensors if you got a lil too rough 

oh also make sure the maf is on the right way I know its a dumb suggestion but I actually put mine on backwords once by noty paying attention 
hope all this helps


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## gaijin_resa (Jun 18, 2005)

studeringaaron said:


> dont need "high flow maf" and dont realy need oil either the oil just traps the dirt a lil better
> 
> try lookin for pinched/kinked vacum lines, try the filter thing look at the couplers that you tightened down make sure there on right and the clamps are on the tubing and not between blocking air flow.
> also where did you put the temp sensor it was on top of the air box and when you put the intake on theres no hole for it you said that it has rough idle till its up to operating temp {gauge in the middle} so mabye you have that temp sensor in a bad place of you killed it by banging it round or somthin
> ...


Actually I left the temp sensor down by where it was plugged in. There wasn't a spot for it in my intake. Would that really kill the engine though? If so, it was located away from my new intake, should I ghetto rig it by extending the wires and find a spot to run it into? I do know that I didn't put it in backwards because I thought that I might have done that, so I checked that already.


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## Captain Obvious (Jan 2, 2004)

gaijin_resa said:


> Actually I left the temp sensor down by where it was plugged in. There wasn't a spot for it in my intake. Would that really kill the engine though? If so, it was located away from my new intake, should I ghetto rig it by extending the wires and find a spot to run it into? I do know that I didn't put it in backwards because I thought that I might have done that, so I checked that already.


unlikly the temp sensor will make that big a differance but it may and I may be wrong also 

dont run it longer { im tired so i dunno the term} but youll mess up the way the electricty runs to the sensor possibly throwing it off 
just make sure its in about the same place it was before in the engine bay away from hot stuff like exhaust mani and stuff 
a good place is the fender well i seen ppl put it there and tie it to a screw hole

try the vac lines make sure none are pinched or cloged and also the prober place for them 
your main prob if it ran fine before and not now is there is an air flow problem thast most possible 
and also leave the battery neg cable off a lil bit cause the ecu may be confused by the new af ratio and compensate by sending more fuel running rich messing up idle till its up to temp to help the more feul vaproize

also some one please correct me if im worng and also theres a write up for a home made intake somplace here so search and see if you cant find that


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## gaijin_resa (Jun 18, 2005)

It is running rich I assume. It has been drinking fuel like water the past day or so.


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## Captain Obvious (Jan 2, 2004)

gaijin_resa said:


> It is running rich I assume. It has been drinking fuel like water the past day or so.


thats cause when you add an intake it sucks more air and the ecu thinks its runin lean so it sends more fuel to make up for it

try resetting the ecu see if that helps that is most likly the culprit do a search here for relearn ecu and youll be cool


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## gaijin_resa (Jun 18, 2005)

Thanks much, I will unplug my battery before I crash for the night and see how she does in the morning.


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## sfhellwig (Feb 4, 2003)

You said you turned up the idle screw. Reason why? Are you sure you turned it up and not down. It's sounds like you have checked most things. Still see about vacuum lines and read that code. The only other thing that has not been addressed is turning the idle screw and by how much. Unfortunately without knowing for sure you will have to completely reset it. As far as I know this involves putting the car into timing mode, at which point I don't think you can trust the tach, at which point you would need a timing light that counts rpms. I could be wrong about that though. Find the FSM sticky to find out the idle reset. You may be able to just have someone watch the tach while you turn the screw. I personally would check that first.


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## DraftEm98 (Jun 29, 2004)

Unless he switched out his gauge cluster, he won't have a tach due to his car being a GXE. A timing light with RPM meter really is the best way to check your RPMs within this scenario. 
The culprit to this problem seems to definately be airflow. Maybe the comp is sending more fuel, but quite possibly it's still sending the same and now you're getting too much air to an already lean car. The strangest thing, besides the idle, is the fact that the car has to warm up before properly idling. Maybe taking a voltmeter to the MAF and IAT (intake air temperature) sensors would detect a fault somewhere. A sensor might not even have been completely plugged back in.
Either way, clearing your ECU first helps. After clearing, turn the ignition to "ON" and see if the CEL comes on again. If it does, than you will need to find the fault code to find out what the ECU diagnosed problem is.


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## gaijin_resa (Jun 18, 2005)

DraftEm98 said:


> Unless he switched out his gauge cluster, he won't have a tach due to his car being a GXE. A timing light with RPM meter really is the best way to check your RPMs within this scenario.
> The culprit to this problem seems to definately be airflow. Maybe the comp is sending more fuel, but quite possibly it's still sending the same and now you're getting too much air to an already lean car. The strangest thing, besides the idle, is the fact that the car has to warm up before properly idling. Maybe taking a voltmeter to the MAF and IAT (intake air temperature) sensors would detect a fault somewhere. A sensor might not even have been completely plugged back in.
> Either way, clearing your ECU first helps. After clearing, turn the ignition to "ON" and see if the CEL comes on again. If it does, than you will need to find the fault code to find out what the ECU diagnosed problem is.


I tried to relearn the ecu and that didn't work, so I am going to diagnose the cel now....


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## Captain Obvious (Jan 2, 2004)

gaijin_resa said:


> I tried to relearn the ecu and that didn't work, so I am going to diagnose the cel now....


ya we have covered almost everything we can think of
I had a 96 qxe auto that did the same thing it was a pinched off vac line

im guessin that you inadverntly broke a sensor or somthin


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## WiZzO (Jun 15, 2005)

studeringaaron said:


> ya we have covered almost everything we can think of
> I had a 96 qxe auto that did the same thing it was a pinched off vac line
> 
> im guessin that you inadverntly broke a sensor or somthin


agreed he said he already checked the lines though and according to him he didnt break the sensors but thats still what i think it is...they break easier than you think


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## sfhellwig (Feb 4, 2003)

Find somebody with a GA16 of the same or close year and swap the sensors to see if it changes. That is if you have a friend who's willing to help you diagnose this. It would suck to pay for those expensive ass sensors and that not be the problem.


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## gaijin_resa (Jun 18, 2005)

Yesterday, I pulled the ECU out and did a diagnosis. I got 0401 which my haynes says is an IAT (intake air temp sensor) failure. I called the local parts store to find out what the price is on one of those, they said that they don't carry it, nor do they carry an engine coolant temp sensor. The parts store guy said that it may be the engine coolant temp sensor because he has seen the same symptoms in a gm that are caused by a bad sensor. So now I have to call my local nissan dealership to see if these sensors are cheaper than a MAF because an MAF is $160 from O'Reilly's... Oh by the way, I unplugged my MAF yesterday and the car idled fine, when I pressed the accelerator though, it revved up and down real hard, so I don't really think that the maf is bad because it would do that when I was driving right? If it was broken? My stepdad is still insisting that the ecu can't handle that much of an airflow increase without putting in a high flow maf or some comparable part. However, this "high flow" part eludes me. I have found no mention of it anywhere.... I was thinking junkyard to see if I could find a cheap MAF.... I will update if there are anymore developments. By the way, there are pics of my setup on my cardomain, if that helps any.


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## Captain Obvious (Jan 2, 2004)

gaijin_resa said:


> Yesterday, I pulled the ECU out and did a diagnosis. I got 0401 which my haynes says is an IAT (intake air temp sensor) failure. I called the local parts store to find out what the price is on one of those, they said that they don't carry it, nor do they carry an engine coolant temp sensor. The parts store guy said that it may be the engine coolant temp sensor because he has seen the same symptoms in a gm that are caused by a bad sensor. So now I have to call my local nissan dealership to see if these sensors are cheaper than a MAF because an MAF is $160 from O'Reilly's... Oh by the way, I unplugged my MAF yesterday and the car idled fine, when I pressed the accelerator though, it revved up and down real hard, so I don't really think that the maf is bad because it would do that when I was driving right? If it was broken? My stepdad is still insisting that the ecu can't handle that much of an airflow increase without putting in a high flow maf or some comparable part. However, this "high flow" part eludes me. I have found no mention of it anywhere.... I was thinking junkyard to see if I could find a cheap MAF.... I will update if there are anymore developments. By the way, there are pics of my setup on my cardomain, if that helps any.


ok I hate saying stuff like this but do not listen to your stepdad
thats like my father in law hes been a mechanic for years and he knows his stuff in the old school but the newer cars with sensors and ecus and all that crap he knows squat about

if its throwin a code for the ait sensor then most likly you bumped teh sensor and blew it out
sensors are a pain in the butt abd they get expensive and the reason why the high flow part eludes you is casue there is no such thing you can get a bigger maf but that will screw things more 

i was re reading your posts and your first mistake was messin with the idle screw try to get that reset back to stock find a service manual to help you.
second was it is throwing a code you got that code and it says temp sensor i mentioned that before casue it runs fine when its at temp.
you reset the ecu and nothing happens so then it is mechanical not with the ecu,

so a lil recap of these problems shows me that it is most likly not the maf cause if it is then it will raise and drop rpms like when you unplug it but I think its your temp sensor and thats without lookin at it though.

its not hard to bust that lil filiment 
if your step dad insists on a high flow maf for the nissans then assure him that a service guy for pep boys (yours truly) told you that there is no such thing and he will say well thats pep boys there not real mechanics and tell him you will ask a nissan pro about it and call greg v up or pm him ask him bout this high flow thing and then order a temp sensor and replace that 
he is a head parts guy for a nissan dealer in san deigo and a great guy and not to forget a member here :thumbup: mabye he can cut you a lil break or at very least he will make sure you have the correct part
sorry for the long ass posts but I want to make sure you get taken care of here


EDIT: I just looked at yoru setup and it looks ok except I have never put the intake tube after the maf 
I have always used teh adapter and put the filter to the maf like this 

Intake manafold-->intake tube-->MAF--> coupler-->filter
yours is like this 
Inatke man-->coupler-->maf-->tube-->filter
try putting the shortest tube between filter and teh maf then the longer tube on the intake manafold
but still i beleive strongly that its the temp sensor
try switching it round first though cause of your maf so close to the engine you may be throwin the temps off


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## gaijin_resa (Jun 18, 2005)

ok I will switch it around, it just didn't look like it would fit right if I had the maf after the tube, but I will see what that does... Thanks for all the help.


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## sfhellwig (Feb 4, 2003)

Yes definetely change that around FIRST. Sorry we didn't look at that earlier. Not to say that the system couldn't be run that way but I have never seen it done like that. Not saying anything bad about the way you installed it either, just want to rule out the free stuff first. Make sure you reset the ecu after the switcheroo or at least drive it for a while. Don't expect the cel to go away immediately unless you manually clear it.


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## DraftEm98 (Jun 29, 2004)

I've never seen a MAF done that way. Hell, i've never seen anybody make a Bomz kit work! Better get a new filter, though, if you're using theirs. I wouldn't trust it.
On to your problem... Even though I have a CAI, I tried what you did with the MAF. Not good, my man, not good. I think my main problem was that the MAF was WAY too close to the throttle body. Not sure why that is, but it made for some funky throttle. Change that stuff up and if it doesn't help than go with a new IAT sensor. Cut and splice from a junker. Shouldn't cost much scratch and at least you'll know you've got a new IAT sensor!


Daron


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## 200sx_guy (Nov 13, 2004)

gaijin_resa said:


> Yesterday, I pulled the ECU out and did a diagnosis. I got 0401 which my haynes says is an IAT (intake air temp sensor) failure. I called the local parts store to find out what the price is on one of those, they said that they don't carry it, nor do they carry an engine coolant temp sensor. The parts store guy said that it may be the engine coolant temp sensor because he has seen the same symptoms in a gm that are caused by a bad sensor. So now I have to call my local nissan dealership to see if these sensors are cheaper than a MAF because an MAF is $160 from O'Reilly's... Oh by the way, I unplugged my MAF yesterday and the car idled fine, when I pressed the accelerator though, it revved up and down real hard, so I don't really think that the maf is bad because it would do that when I was driving right? If it was broken? My stepdad is still insisting that the ecu can't handle that much of an airflow increase without putting in a high flow maf or some comparable part. However, this "high flow" part eludes me. I have found no mention of it anywhere.... I was thinking junkyard to see if I could find a cheap MAF.... I will update if there are anymore developments. By the way, there are pics of my setup on my cardomain, if that helps any.


I noticed you mentioned a coolant temp sensor... coolant temp sensors don't mess up the way the car runs. I had one go out on me last summer before i put my car in storage. check the other sensor first. I just wanted to make another comment about the high flow MAF. I run a turbo setup on my 200sx which is going to pull in alot more air then a NA car with an intake and i'm still running a stock MAF


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## DraftEm98 (Jun 29, 2004)

you can upgrade to the JWT Cobra maf, if you have the neccessary means to do it. it wouldnt do much on a stock ga16 motor, though, due to the throttle body.


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## gaijin_resa (Jun 18, 2005)

GAR! stupid ebay! They sent me the wrong maf adapter, I bought a new one... Now it runs great! Great sound, and I know that the butt dyno isn't to be trusted, but it feels more torquey. Thanks for all the help!


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