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car idling funny after tid mod???

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Old Jun 11, 2002 | 10:22 PM
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Unhappy car idling funny after tid mod???

i did a tid mod, cone fitler and a 3" pipe from the afm to the trubo. I was boosting 10psi before this mod, and when i tested car with this mod i was boosting 13psi!! Now i was driving around for the whole day, and at night i was beating on it, and when i get home the engine is idling really rough. The car is shaking from it. I am wondering if one of the vacums lines poped off?? Or can it be somthing else?? ( i have a walbro 255 fuel pump, and a s-afc) Im hoping i didnt **** anything major up.
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Old Jun 11, 2002 | 10:25 PM
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have you checked all the vacuum lines? also check the TID at both ends for leaks. Get some carb cleaner and spray on both ends, if your idle raises when you spray it, wherever you just sprayed is your leak. But dont blame me if you catch on fire!
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Old Jun 11, 2002 | 10:36 PM
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umm 13psi is alot!. was that at night? or was it even higher at night? (it would be)

I'm sorry to say but definatly do a compression test as a first step.. unless you see anything lose around the TID.
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Old Jun 11, 2002 | 10:44 PM
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well i havent checked the vacums yet seeing as its late and i have to go to work tomm( going on trip till friday so i cant do anything till then but think about the car) but im really hoping it was just alot of boost and it has a vac leak somewhere..
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Old Jun 11, 2002 | 10:45 PM
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oh btw, at night i was hitting 13.5
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Old Jun 11, 2002 | 10:52 PM
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I bet one end of your new TID is not as tight as it should be. A leak post-AFM will cause a funky idle from unmetered air getting into the engine. Make sure those clamps are really tight.

13psi is a bit too high for the stock turbo. Time to port that wastegate!
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Old Jun 11, 2002 | 10:57 PM
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Yeah...It could be a vaccumm line...But its, more than likely, you blew the motor. Did you mess with the AFC setting ( i.e. richen it up ) before you went flogging on the car?
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Old Jun 11, 2002 | 11:04 PM
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ofcourse i made the s-afc richer!! first thing i did before i even drove it. Also i ported the wastegate a good amount.
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Old Jun 11, 2002 | 11:40 PM
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Fuel pump rewire?&nbsp Any steps to minimize voltage drop at the fuel pump?


-Ted
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Old Jun 11, 2002 | 11:41 PM
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well i was thikning of that, but my friend was saying i migt not need it, see my car has only 31,000 original miles on it, so i am thinking the wiring is still pretty new and good condition. Am i wrong about this??
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Old Jun 11, 2002 | 11:52 PM
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Mileage has almost nothing to do with corrosion.&nbsp Corrosion is more directly related to humidity, climate, and length of time of exposure (i.e. age).


-Ted
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Old Jun 12, 2002 | 04:11 AM
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Originally posted by T210thAnniv
well i was thikning of that, but my friend was saying i migt not need it, see my car has only 31,000 original miles on it, so i am thinking the wiring is still pretty new and good condition. Am i wrong about this??
Your mileage has nothing to do with it. Stock psi is 6.5?
And when you're boosting double what the stock set up is, you're asking for trouble without the proper set up. Because the car has 31,000 miles does not mean there's no voltage drop. Imagine the lights, stereo and accessories on at night. You don't think there would be a drop in voltage at the pump? My car back then had about the same mileage as yours and by chance I took a voltage reading at night . I got 10.6 volts to the pump.
I suggest you rewire that thing. Bumping the fuel map with an AFC isn't going to do jack if your pump cannot keep up.
The DSM list did a test on the 255 Walbro. I remember it flowing best at about 14-15 volts. At below 10 volts , it flowed 50% what it was capable of.
Also 13.5 psi on a stock turbo is too high. And at night you are going to get boost creep with a denser charge.
The stock turbo wastegate is really small. I could barely stick my pinky finger in there. That's how small it is. I ported it to about the size as the flapper door which is now significantly larger.
There have been too many guys blowing their motors with your set up, including me. You should build your power around your fuel set up. Get an A/F gauge or EGT gauge and a fuel pressure gauge. Just having a boost gauge won't tell you jack except for "DUDE ! YOU'RE MAKING A LOT OF POWER!". I don't mean to sound like a lecture but I don't want to see another motor blow up.

Last edited by IWNTA20B; Jun 12, 2002 at 08:21 AM.
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Old Jun 12, 2002 | 06:33 AM
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You rough idle is most likely caused by a vacuum/air leak somewhere. Shortly after my TID mod I got some strange starting/idle concerns. I finally traced it to the reducer, where it attaches to the turbo. If you are using the universal screw-type clamp, you need to get a better clamp that has some sort of locking nut. My original one would work itself loose very quickly and allow the reducer to pull off. This gave unmetered air flow which is extremely dangerous to the engine.

Also, REWIRE your fuel pump. It's fairly easy, inexpensive, and will save your engine!

Mike

Last edited by 89turbo2dutch; Jun 12, 2002 at 06:36 AM.
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Old Jun 12, 2002 | 06:34 AM
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WELL I ALREADY MENTIONED THAT I PORTED MY WASTEGATE AND I DO HAVE A EGT GAUGE AND A WATER TEMP GAUGE. THEY WERE ALL FINE AND NORMAL AS BEFORE THE PROBLEM. I DROVE IT THIS MORNING TO WORK AND I PUSH ON IT, FELT THE SAME AS LAST NIGHT. STILL RUNNING STRONG, THE WATER TEMP WAS AT 190 DEGRESS AND THE EGT WAS BETWEEN 12-14. aLL MY GAUGE ARE SHOWING NORMAL READINGS, GUT I DONT WANNA RELY ON THEM AS I KNWO THEY NOT 100% ACCURATE. WELL NOW THE CAR IS IDILING AT AROUND 1000RPM. WONT GO LOWER. IT STIL SHAKES BUT NOT AS MUCH AS IT DID LAST NIGHT AT 700RPM
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Old Jun 12, 2002 | 06:52 AM
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Do you have a sore throat ?

Best bet: vacuum leak. Something couldnt take the pressure and snapped/came off. Dont think its a seal, because you would definitely feel it...
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Old Jun 12, 2002 | 07:04 AM
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ok i just looked at it outside(at work) at the car and i saw that the reducer is half way off the turbo outlet! i couldnt see this last night since i didnt have a flash light , but as i said it was reving around 1000rpm this morning to work and i just pushed it back on and tighten it and now its reving 700 again, still rough but i think thats the problem so i wil have to get another reducer, guess this one is cheap.
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Old Jun 12, 2002 | 07:20 AM
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Originally posted by T210thAnniv
ok i just looked at it outside(at work) at the car and i saw that the reducer is half way off the turbo outlet! i couldnt see this last night since i didnt have a flash light , but as i said it was reving around 1000rpm this morning to work and i just pushed it back on and tighten it and now its reving 700 again, still rough but i think thats the problem so i wil have to get another reducer, guess this one is cheap.
Dont you have a clamp on it ? If not, do so now. Its, what, 1,5 bucks ? And it will save you a lot of trouble and grief

And if something came loose, chances are something else will too....go over all of the parts of your TID and double-check all connections, and tighten everything with clamps. You will feel better too....
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Old Jun 12, 2002 | 08:22 AM
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Is your BOV vented now? All the T2 BOVs I've vented have leaked, and needed a 1-way check valve. Other than that look for any sort of loose/unclamped hose, leak, etc, after the AFM.
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