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Discussion Starter · #1 ·
hey.. after my crappy homemade intake a while ago (like maybe 4-5 months?) my CEL came on.. it came on as soon as I installed my home made intake (the first drive i took with it on..) All I did was take off the VAF or MAF (whatever I have, its made outta metal [silver color] and has two holes but no plunger type thing), the old air box, clear the VAF/MAF, put it back on, put back the old air box with a clean filter, and stuck aluminum pipe to the bottom of my car.. the light says: running too lean.. anyway about a month ago my car started idling rough too (im saying around 500 range and sometimes it dips below and the car shakes).. it keeps getting worse but i have no clue what the hell is wrong.. BTW, right after the CEL came on after a bout a couple of days I put the stock intake back on, but the light still came on even tohugh i resetted computer and all (so I musta jacked up something when i installed my intake..) I hear a whistling noise that sounds like its coming from the intake (i put my ear up to the intake and its loudest) so im guessing i musta knocked a vacuum hose loose or something? I put a ractive filter hooked up to my stock intake now and made holes for that one vacuum hose that goes into the factory airbox and the IAT so i know those arent the problem. What other hoses are in that vicinity? isnt there a way i can see if a vacuum hose is loose by spraying something inside the engine bay while my car is on and see if the car turns off or starts shaking or something like that? I have no clue what the hell is wrong with my car.. If you have ANY clue or comments, please do post.. thanks

OH yeah.. i changed the o2 sensor too but the CEL is still there..

jason


[Edited by ATLien1222 on 11-14-2000 at 06:15 PM]
 

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You don't mention if you have the 2.0L or 2.5L. It certainly sounds like the symptoms of an air leak when I have had them on another car.

I always "looked" around with a can of WD-40 to find air leaks on my carbureted MG. I don't know if that's safe to do on a fuel-injected car though.

Tyson
95 LS (for sale)
 

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ATLien1222,

With the I4, you do indeed have a MAF sensor.

As mts3 pointed out, it sounds an awful lot like a massive vacuum leak.

Can we assume that with both the stock airbox and the homemade kit that you retained the factory throttle body ducting? If so, take it off the car. Examine it very closely for cracks, especially where the duct has ribs. Hold it up to a bright light and twist and flex it to see if any light gets through a hard-to-see crack.

Hanging off that duct is a resonance chamber...make sure it too is not cracked. Make sure its clamp is tight.
 

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Discussion Starter · #4 ·
k..appreciate all your input.. I'll first look for cracks in throttle body and then I'll do the WD40 trick if that doesnt work hehe, is it safe (the wd40)? ill reply after i do it tomorrow.. thanks again guys..

jason
 

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Just as a side note. When I removed my factory air filter box. I attached a breather filter to the hose that went into the box and shoved it to the side. Check the TB elbow and also check for any other hoses around that area. both by the firewall and underneath the factory air box. If you see a hose, gently pull on it and follow where it gets connected to. Then make sure that it's connected properly and move on to the next.

Also, if you do the VAF to MAF convertion or vice versa, I was under the impression that it's not a direct bolt on. I mean it is but you have to do some rewiring for the sensor to read correctly. Someone here has a page on it, I forget who. Maybe it's not a leak but just the sensor on the MAF that is not working properly. I remembe when I removed my intake manifold, at the end i forgot to plug in the sensor and the car started but ideled horibly and the entire car shook. When I plugged it in. it was back to normal..... I would look into that.
 

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Discussion Starter · #6 ·
k man thanks appreciate all the help.. im not plannin on doing the maf/vaf conversion but i was just figurin out which i had, and i was told the maf. anyway, i installed my fuel filter today and had to take my ractive filter off and i started the car with just the TB elbow (the MAF was idsconnected and off to the side) and there is a loud whistling noise.. i recorded the sound and ill be be back in 10 mins and post it.. thanks though

j
 

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Wait a minute, why would you start the car with just the elbow without the MAF? the car is DEFINITELY not going to run smoothely without the MAF in place and the sensor attached....I hope you're not planning on leaving it off or something......I would reinstal everything and then resent the ecu and have the car learn all the settings over again.

Maybe I'm missing something.
 

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Discussion Starter · #8 ·
no i started it primarily to see if the whistle noise would still be there, not to see if the car ran smooth. I'm trying to figure out where exactly the whistling noise is coming from..

I have WAVs of it up, please listen to them and tell me what you think they may be.. it sounds like a leak or something?
engine on: http://mx6.2y.net/~jdp/on.wav
(when it gets louder, thats me moving mic closer to the elbow)
engine on and then turned off: http://mx6.2y.net/~jdp/turnoff.wav
(listen to this one especially, you can hear it turn off which sounds like a vacuum leak maybe?)


thanks

jason
 

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I don't know ATLien222. Those both sounded pretty normal to me. You might find that the noise will change in pitch and severity if you turn the idle speed screw on the IAC valve a bit.

You have to remember that every two turns on the crankshaft, the engine tries its darndest to inhale 2L of atmosphere. At idle, the engine is turning 700 times a minute or 11.67 times each second. That means it's trying to inhale 11.67L of air every second. Clearly it can't do that with the throttle closed but it's still trying and quite a bit of air gets by the tiny gap between the throttle plate and the throttle body (and through the IAC valve). You hear this as the whistle. Crack the throttle suddenly and listen to the air literally gulp for air...

JPM: I have a MAF converison on my PGT. The 4-banger came from the factory with a 50-55mm MAF sensor, unlike the 2.5L VAF.

ATLien...have you cleaned the MAF sensor elements recently?
 

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Hey Jason, did you fix this problem yet? If not, come down to the next apoc meet and let pardus or wes look at it, they more than likely can tell you exactly what the problem is. Wes had taken his motor apart several times, and also put in his KLZE

Later Jason
Robert
 

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Discussion Starter · #11 ·
i got my CEL taken care of (new fuel filter) but for my idle prob i just raised the idle a bit but thats kinda ghetto so i have to find the real reason.. I need to change oil and oil filter so i'll prob do that soon.. when is the next meet? thing is i got guest all this week so i doubt ill have any time to ditch them heh


j
 
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