My Problem... yes that's right... again

david-b · #1 01-25-2007, 12:05 AM

Hey;
This has to be my 2654518441 post on this problem already. The problem, for those of you who forgot, is that when I let off the gas, the idle will drop to 1200, then shoot up up to 2000 rpm, and won't fall until I almost stop. I'll then get some idle surge until I fully stop.

-The last 2 days now, it's gotten worse. When I let off the gas, it falls, then shoots up to about 2300rpm. It falls to 1500rpm then and surges around there until I almost stop.

-This morning when I started the car, it sounded so bad. Sounded like maybe it was on 3 cylinders, but all was well. It warmed up and was fine.

-Another problem. I floored it at one part in a mid 3rd gear. Car took off, then sat there and stuttered until I let off the gas. Did that twice today.

-And lastly I've noticed here, which I think relates to problem 1, when I'm driving and say I let off the gas but keep it in gear, the car wants to keep moving. Like instead of it slowing down, it feels like the throttle is still somewhat open. So the car will actually pick up speed for a little bit when I'm not on the gas. The TPS on the SAFC isn't showing it moving at all.

I'm going to loosen up the throttle cable when I get a chance. I don't think that's the problem at all. Never had issues before this bad. It's scaring me a little. I'm thinking I may take it in to my shop and get the diagnostic done on the it for the $60 or whatever they charge to figure it out once and for all. PCV valve is new (Brain!)

l_eclipse_l · #2 01-25-2007, 12:48 AM

I thought only turbo DSM's had as many idle problems as you do....lol

Mikelb · #3 01-25-2007, 09:51 AM

^lol, sorry you are having such problems... I'd say check the TPS and all of its connections... your sensor might be going or you might have a short in the wires... have someone wiggle the connector while you push the throttle and monitor the AFC...

gthompson97 · #4 01-25-2007, 11:33 AM

Have you checked every sensor that could possibly be related to idle? The TPS like Mike said? IAC? If not, you should. If you need directions on how to check them, let me know, I'll get them for you.

Mikelb · #5 01-25-2007, 11:37 AM

To be completely honest with you David, I believe that it is the TPS. I am almost 90% sure that's where the problem lies...

I'm not saying that the TPS is in itself bad, but make sure it has a good connection and is set right.

My Talon Tsi, there's no metal clip that goes around the harnesses (TPS, CAS, FIs,etc) and whenever I get idle surge, I check the TPS voltage and percentage on my AFC, and it's not reading correct...
All I have to do is get out of the car and fix the connection, and the idle goes from being crazy (1200-1800 rpms up and down) to a perfect idle (~800 RPMs)...

Check the TPS...

david-b · #6 01-25-2007, 01:24 PM

The TPS is brand new. I'm waiting for it to get warmer so I can take apart the TB and make sure evetyhing is good.

Mikelb · #7 01-25-2007, 01:32 PM

Quote:

Originally Posted by david-b

The TPS is brand new. I'm waiting for it to get warmer so I can take apart the TB and make sure evetyhing is good.

damn, that's right... I forgot, you told me you were buying one...

make sure those wires aren't broken or shorting out...may also wanna take a peak at the ECU (I realize you aren't turbo, but it might have still developed a problem)...

david-b · #8 01-25-2007, 04:11 PM

All the wires, pins, and clips are fine. I'm going to just have to tear apart the TB and see if that's where the problem is lying. Damn, it's only going to be in the teens around here for a while. Burr.

gthompson97 · #9 01-25-2007, 06:09 PM

Okay, you've probably told us 100 times, but I'm going to ask again. What parts have been replaced and which ones have been tested so you know they're good. When did this problem start, was it when you first put on the new TB? I've read a few times that incorrectly bored TB's can cause some really fucked up idle problems, so that may be a problem.

david-b · #10 01-25-2007, 08:01 PM

Quote:

Originally Posted by gthompson97

Okay, you've probably told us 100 times, but I'm going to ask again. What parts have been replaced and which ones have been tested so you know they're good. When did this problem start, was it when you first put on the new TB? I've read a few times that incorrectly bored TB's can cause some really fucked up idle problems, so that may be a problem.

-I've replaced the TPS with a brand new one. I'm going to test it when I get the TB off the car soon.
-The IAC was replaced a long time ago, but with a used one. I want to get a new one, and I think I may this weekend. May as well.
-The problem has been bad for a while. It started happening when I first got aw P0420 code (EGR flow). Travis is sending me a low mileage EGR valve and solenoid and I'm going to replace it.
-The bored TB looks fine. It's going straight through and the butterfly plate is excellent. No leaks or anything.
-Gasket brand new. Everything is hooked up great, no leaks.
-PCV valve and hoses are new.
-Air filter is clean.
-Fuel filter was changed last year.

I have some time on Sunday, so I think I'm going to take care of it then. Going to take off the TB, sensors, get a new IAC, clean everything, and test everything. Then reseal all the gaskets and see if that changes anything. If not, once I get the EGR in, I'll install that and see if that fixes anything. If not then, then it's going to my shop for diagnostic check. Sound good?

gthompson97 · #11 01-25-2007, 11:18 PM

Sounds like you're on the right path, nothing else I would change. Just make sure you check and double check all those sensors.

david-b · #12 01-25-2007, 11:22 PM

Today the car wasn't as bad as yesterday was. It was back to normal problems, and actually running pretty well for the most part. Didn't push it to do anything, but she ran good. Sunday will be my day, maybe even Saturday if I find some time in the morning. Saturday morning plans got cancelled so I'm open again.

gthompson97 · #13 01-26-2007, 11:48 AM

Did the weather change anything drastically? Could it have something to do with a temperature related problem that's making things worse?

david-b · #14 01-26-2007, 12:47 PM

It was really cold the other day, like 14 or so. The car also sat in the garage for 2 days without moving. But I took it to work, and it sucked balls. Its a 5 mile trip or so. After work (which was still freezing) it sucked a lot too going to my girls house, about 8 miles from there (10 minutes or so). Yesterday was about 20.

This weekend is going to be about 10, so I don't know if I'm going to have a chance to check everything out. I don't have a heated garage.

david-b · #15 01-27-2007, 04:25 PM

Ok well today was kinda nice so I decided to take it all apart. Took off the TB and cleaned it. Check the IAC and TPS with the Ohm meter and they checked out fine. The TPS was a little loose, and the IAC could have been on there better. Don't know how that happened, but yeah. Also sprayed from carb cleaner down the EGR pipe from the intake.

Did a test drive and so far the thing is working fine. That's usually the case, so I'll give it some time and see what happens. The SAFC is also showing 82% at WOT unlike the 75% it did before. Still don't know why it does that, but it's more steady right now too. I'll keep driving and see what happens.

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