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


david-b
01-24-2007, 11:05 PM
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
01-24-2007, 11:48 PM
I thought only turbo DSM's had as many idle problems as you do....lol

Mikelb
01-25-2007, 08:51 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
01-25-2007, 10:33 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
01-25-2007, 10:37 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
01-25-2007, 12:24 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
01-25-2007, 12:32 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.

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
01-25-2007, 03:11 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
01-25-2007, 05:09 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
01-25-2007, 07:01 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.

-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
01-25-2007, 10:18 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
01-25-2007, 10:22 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
01-26-2007, 10:48 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
01-26-2007, 11:47 AM
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
01-27-2007, 03:25 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.

gthompson97
01-27-2007, 03:29 PM
What directions did you use to install the SAFC? The ones from 2gnt.com? I have a feeling there's a problem somewhere either with your SAFC wiring, or the TPS harness, it's just too weird of a problem for it to be anything mechanical.

david-b
01-27-2007, 05:07 PM
TPS harness is perfect. Used directions from all over. Kinda took them all, read them numerous times, and then installed it then. It used to read 100%. Then afterward when I got the new TB, it didn't. It would say like 50% at WOT. Playing around with it an "fine tuning" got it to bring it up to 75%, and now it's at 82%. I haven't seen anything in the AFC to adjust that. Do you think I should do a reset on the AFC?

gthompson97
01-27-2007, 05:37 PM
Yeah, I would write down the settings and do a master reset. But if it used to read 100% before the TB install, then it must have something to do with that bored one you bought.

david-b
01-28-2007, 12:09 AM
But that doesn't make sense. Nothing changed. The butterfly still opens the same. The tension is set correct to where the plate opens all the way at WOT. TPS is new. And now that I'm thinking about it, the new one at a tme did read 100%. However, when that read 100%, the datalogger was really low then. I haven't hooked the logger up to here in a while, so I'm not sure what the reading is. I'm going to try the reset tomorrow and see what happens.

I took a pretty good size trip to a friends cousins house for a graduation party. The car ran great. There was a little idle surge, but nothing major. Once the car warmed up fully, each time I shifted out of gear, the rpms dropped perfect. Even when shifting between gears, I noticed the rpms were dropping very quickly compared to just hanging there. Good and bad, but you know.

Even did an expressway run against a white "GST". That's in quotes because it obviously wasn't. Had a mufler and I think that was all. He couldn't catch up to me at all while doing 80-110. Close, but couldn't pass. Maybe it was slower because his drivers side rear window was made of tape.

So again, I'm goign to reset the SAFC tm and see what happens there about the readings. Besides that, so far so good. We'll see though

gthompson97
01-28-2007, 02:53 AM
Dude, your car is fucking weird. Some days it's fine and some days it's not. Problems like that sometimes NEVER go away. Maybe it's got to do with the engine temp? I have no idea anymore.

defiancy
01-28-2007, 03:21 PM
Maybe you should try swapping in a different ECU.

I mean you have tried everything else. Might as well throw in the kitchen sink as well.

david-b
01-28-2007, 09:46 PM
Dude, your car is fucking weird. Some days it's fine and some days it's not. Problems like that sometimes NEVER go away. Maybe it's got to do with the engine temp? I have no idea anymore.

Well engine temp is fine. If you recall, I had that thermostat problem earlier but is fine now. It does happen when the engine is cold, but that's understandable. Damn, it's going to be about 0 degrees this week now. :banghead:

Today my radar detector came up High Voltage a couple times. Voltage gauge was reading high. Any relations with that and possible the ECU?

I'm trying to get all this shit straightened out now before I do the head swap so I know everything is fine for when I do it. I know that if something doesn't work, it's because of something I did/changed then.

gthompson97
01-28-2007, 10:28 PM
I don't think the voltage gauge, ECU, and radar detector really have anything to do with one another, so my guess is no.

And my last post, yeah I was drunk so I just kinda rambled. But what I meant was that maybe the temperature of the engine has something to do with the problem. Does it seem to get better as the engine temp heats up, or is it just at random times?

Mikelb
01-29-2007, 07:51 AM
did you adjust the TPS sensor, for the WOT?

david-b
01-29-2007, 07:11 PM
did you adjust the TPS sensor, for the WOT?

On 420a's its not adjustable. It's just a straight bolt-in. Not adjustable like the 4g63.

I was just saying about the voltage because it's a new problem coming up. It did it again today for a little bit also.

It does happen more frequently when cold, yes. BUT, it also happens a lot when fully warmed. I'm honestly thinkin EGR valve. It seems to me that its sticking open, filling the IM with exhaust when it shouldn't be. When I pulled the TB on Saturday, the back of the butterfly plate was filthly. I've never seen it that black... and we know what makes the IM dirty on the inside :rolleyes:

Mikelb
01-29-2007, 08:14 PM
On 420a's its not adjustable. It's just a straight bolt-in. Not adjustable like the 4g63.

I was just saying about the voltage because it's a new problem coming up. It did it again today for a little bit also.

It does happen more frequently when cold, yes. BUT, it also happens a lot when fully warmed. I'm honestly thinkin EGR valve. It seems to me that its sticking open, filling the IM with exhaust when it shouldn't be. When I pulled the TB on Saturday, the back of the butterfly plate was filthly. I've never seen it that black... and we know what makes the IM dirty on the inside :rolleyes:

Ah, sry... it's only been a few months since I haven't had my 420, but still a long time compared to the time I had it (and worked on it)...
Sry, I don't know what else to tell ya then...

Wick3D-PimP
02-07-2007, 09:29 AM
Hey man i've got he same problem is you except that i fixed the idling problem by changing the engine coolant sensor. Aparently when that sensor is bad... the car dumps way to much gas into the engine causeing it to surge funny like that.
However i still have the same misfire problem u have.. at low rpms if i give it to much pepper it stumbles like its misfireing a piston.. then after about 5000pms itll randomly buck..
And now scince its been cold it is randomly idling between 500-1000 rpms, it starts at 800 then sounds like it gunna die.. then picks up to 1000 rpms then comes down again and repeats.

gthompson97
02-07-2007, 10:32 AM
And now scince its been cold it is randomly idling between 500-1000 rpms, it starts at 800 then sounds like it gunna die.. then picks up to 1000 rpms then comes down again and repeats.

Have you checked the IAC yet? I'm betting that's the problem.

Wick3D-PimP
02-13-2007, 11:49 AM
Just an update.. the low rpm idling problem was fixed by removing air bubbles from my cooling system :)

And the problem with the misfireing.. im 95% sure i jumped a tooth on the intake cam. Anyone know of any ghetto methods of fixing the timing without taking that entire side of the engine out? I was thinking about just breaking the timing belt caseing then attempting to get a little slack then adjust the cam...?

Also is there anything bad that can come of not having the case on the timing belt?

gthompson97
02-13-2007, 12:55 PM
No, there's no "ghetto way" of fixing the timing belt, you'll just end up with a bunch of "ghetto broken parts." You have to do a complete job to get your car fixed right if you did in fact jump a tooth.

Mikelb
02-13-2007, 01:13 PM
^you don't have to have that cover, but why wouldn't you want it?

The manufacturer put it there for a reason, and thousands of cars have gone millions of miles(collectively) with them in place. I'm sure there are people who run without them, but that's putting the engine at more of a risk. The cover protects that belt, and your valvetrain (to some extent). I'd do things right the first time...

Wick3D-PimP
02-13-2007, 03:21 PM
Well id prefer to do it the right way.. but i dont have a heated garage or a garage period and its COLD AS HELL right now. I was just hoping for an easy fix otherwise i have to ride on sputter o' matic till it gets warm again.

gthompson97
02-13-2007, 05:10 PM
The problem you described in your other post I don't think would be related to the timing being off, because if it was, then the car would run like shit through the whole rpm range, not just for awhile and then take off like a raped ape. What exact problems are you having, because I'm willing to bet its a sensor of some type. And CELs?

You don't *need* to run with the timing belt cover, but I would recommend it. It protects the belts like mike said, and if you get a rock or stone, or something else caught in there, it could shred the TB to pieces, leaving you with a bunch of bent valves and a car that doesn't run.

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