: 00 DTS Falls Flat on Face



Aurora By Olds
01-16-09, 08:10 PM
My 00 DTS has been doing this for the last few weeks that I've had it. It started out very intermittent, but has gotten worse and worse. See YouTube vid below:


http://www.youtube.com/watch?v=DAnTf9corX0

This only happens when the throttle comes off of idle (can happen in P, D, at 10, 20, 50, 90+ MPH) and it totally falls flat on its face and stumbles until I pull my foot off. If I immediately pull my foot off and jam it back on, it's fine. Just replaced the Fuel Filter and from what I can guess the FP is ok (36-46psi) because I don't know the actual specs off hand. The pump and pressure do seem responsive enough to not be the problem.
Once the stumble has passed, the call will pull hard and ever all the way to 130 or until I let off.
It almost seems more like an electrical problem than a fuel problem at this point, but I don't really know where to start. Any ideas?

dkozloski
01-16-09, 10:24 PM
Pull the codes.

Aurora By Olds
01-17-09, 02:33 AM
Pull the codes.

Forgot to mention....there are none. :-(

Ranger
01-17-09, 01:08 PM
It does seem more electrical than fuel, but beyond that, I can't think of anything.

STSj90
01-17-09, 03:15 PM
Is she breathing good? Is there anything in the way of her nose?Anything obstructing?(intake)

What kind of fuel is she running on? maybe you ran into some bad gas?

Just throwing some idea's around...

codewize
01-18-09, 06:43 PM
I think what you may be seeing in that video is it hitting the rev limiter at 4k. Just a thought.

STSj90
01-18-09, 07:26 PM
I think what you may be seeing in that video is it hitting the rev limiter at 4k. Just a thought.


Doesnt sound like 4000RPM to me. Sounds like its bogging when you give it a sudden dose of throttle. Then you lift up alittle and it revs on up.

codewize
01-19-09, 11:41 AM
OK, Just wondering.

For some reason 4k never sounded like 4k to me on the N*. It was just an idea.


Doesnt sound like 4000RPM to me. Sounds like its bogging when you give it a sudden dose of throttle. Then you lift up alittle and it revs on up.

chubbyranger
01-19-09, 12:32 PM
Bad spot in the TPS?

Aurora By Olds
01-19-09, 11:54 PM
Bad spot in the TPS?

TPS was my first thought, but it's intermittent, and only happens when coming off of idle. Get right back on, and it goes like a raped ape.
Its breathing fine, no leaks or obstructions. And again, its intermittent.
Definitly not hitting the rev limiter, not even close.

Still no codes, except for the notorious B0429....

Maybe I will take it out tomorrow and show it whose boss for a few hours and see if anything pops up other than burnt rubber....

Ranger
01-19-09, 11:58 PM
You know, now that you mention it, I recall our old Guru saying that a bad TPS would act like a bad accelerator pump on a carburetor. Exactly what you are describing.

codewize
01-20-09, 09:16 AM
You're right, I had that on my 89. I guess I wasn't thinking about that.

Aurora By Olds
01-20-09, 09:55 AM
You know, now that you mention it, I recall our old Guru saying that a bad TPS would act like a bad accelerator pump on a carburetor. Exactly what you are describing.

Guess it's possible. I'll see if I have time to check into one today. if I remember from the last time I had to buy one they're not that much.
It does actually make sense, though. Idle (or close to it) signal to the PCM from the TPS with a WOT would do just what it's doing...

chazglenn3
01-20-09, 10:22 AM
Okay...I'm confused. If the redline is up in the 6K range, why would the car hit the rev limiter at 4K???

Ranger
01-20-09, 12:05 PM
Yes.

Mark C
01-20-09, 12:27 PM
Rev limit in Park or Neutral is around 4200 rpm, different than the "in gear" rev limit.

tateos
01-20-09, 07:36 PM
Okay...I'm confused. If the redline is up in the 6K range, why would the car hit the rev limiter at 4K???

I think he meant in Park

codewize
01-20-09, 07:59 PM
The rev limiter in park or neutral is 4k. The car is obviously not in D while you're under the hood revving it up.

I think we've determined that this is not what happening, but again I thought I'd throw it out there.

I'm now in agreeing on the TPS idea.

chazglenn3
01-21-09, 12:37 PM
Oh...I see. I read the forum at work and the company firewall blocks You Tube videos. So, since I couldn't see the video I didn't know it was being revved in the driveway with the hood up. :D

Aurora By Olds
01-21-09, 07:39 PM
The rev limiter in park or neutral is 4k. The car is obviously not in D while you're under the hood revving it up.

I think we've determined that this is not what happening, but again I thought I'd throw it out there.

I'm now in agreeing on the TPS idea.


I was all ready to go get a TPS and put it in, but it stopped doing it alltogether! I drove it around for about an hour the other day, doing everything I could to get it to happen, but no such luck. On the upside, I did find out the fun way that it has stability control :sneaky:
As soon as I can get it to consistently do it again, I'm going to drop in a TPS and see if it fixes it.

codewize
01-22-09, 10:05 AM
That's odd. Maybe it was something stupid like a partially clogged injector?

I don't think the TPS is a drop in part. I could be wrong but I think there's some adjusting required there.

Well glad to hear it's gone and it may never some back. Keep us posted.

STSj90
01-22-09, 07:06 PM
That's odd. Maybe it was something stupid like a partially clogged injector?

I don't think the TPS is a drop in part. I could be wrong but I think there's some adjusting required there.

Well glad to hear it's gone and it may never some back. Keep us posted.

Throttle position sensor requires no adjustment. Thats the ISC(idle speed control) that requires adjustment.

codewize
01-22-09, 11:35 PM
Doh!

Throttle position sensor requires no adjustment. Thats the ISC(idle speed control) that requires adjustment.

Aurora By Olds
02-05-09, 09:58 PM
Ok, so the problem is back and in full force. 80% of the time I step on it, it's doing in now. I replaced the TPS, but it changed nothing. There are still no codes. Its not only starting to frustrate me, but it's become dangerous to try to pull out quick in traffic, because I never know exactly when it's going to happen. Whatever it is, it seems like something is telling the PCM to do it, hence the no codes. It is almost like the engine management of the traction control is taking over (even though there is no TC Active Message, there is no wheel slippage, and TC can be turned off and it still happens) because it will stay bogged down until I let off and get back on it. One time I kept on it for about 30 seconds, and it finally kicked in full power, ripping the tires loose and going like it should. I am steering towards a definite electrical issue here, but I am totally stumped. Other than this, there are no misfires, hesitations, sputters, nothing. Anyone?

codewize
02-06-09, 12:05 AM
That's really dumb founding. Even if it was an out of whack sensor or something there are so many variables taken into consideration by the PCM there should surely be a code of some sort.

So, going back to basics on what I know about carbureted cars doing this.

Loading up on fuel, which I guess isn't possible with fuel injection.
Really advanced timing, so much that it can't be tolerated at low RPM's

So that pretty much leaves us with maybe a FPR problem? Or some type of ignition problem. Have you tested the FPR? If it's over or under pressure the injectors will shutdown. Leaky fuel rail ? Do you smell fuel at all?

BlackCaddy87
02-06-09, 06:26 AM
I had a toyota tacoma with similar symptoms. The cat was stopped up, it would run fine sometimes but others she wouldnt go over 50...It only would get worse. My tacoma had a lot of time in mud holes and on farms so this may not be your problem but it can't hurt to try. Maybe you unbolt your exhaust before the cat and see if it makes a difference...besides sounding like a stock car.

codewize
02-06-09, 10:46 AM
You know, I don't know why I didn't think of that. My Brougham, did that for years, and after all the diagnostics and money we put into the car, it was in fact a clogged cat. BTW everyone that looked at the car, including 2 dealers, told me it wasn't the cat. It definitely was.

Now, having said that, we're talking about a car that has 210k on it. I'm sure yours doesn't and new cats last a lot longer than they did in 1993.

But it's worth a look.

BlackCaddy87
02-06-09, 03:31 PM
my car has started something recently similar to this. it only happens when you put it in 1st or 2nd and give wot. it will pull hard until about 30 then completely cut the power and feels like you're slamming on the brakes. very scary when you're not expecting it. it will do it 75% of the time when you punch it in 1st or 2nd but has never happened in in 3rd or OD. i have p056 and have lost my OD so they could be related

Aurora By Olds
02-10-09, 10:01 AM
Finally got back on here this morning. I haven’t had time to check the Cat, although I am skeptical that it would be that. I checked the FPR, no leaks, drips, nothing.
I did, however, find that the car is now doing this consistently. The funny thing I have noticed is that it only does this when I punch the gas, and the tach is below 3k.
Above 3k, goes like a raped ape.
The other interesting part, is that when I floor it from a dead stop, it bogs, speeds up slowly going put put put until it hits exactly 3k on the tach, and it will instantly go to full power, ripping the tires loose and all. It will consistently do this almost every time now. Again, anything above 3k, is totally fine.
To sum up what it feels like, imagine the engine management of the traction control being fully engaged, allowing the car to just barely speed up, and then popping the TC button off and having it fly like the wind. This is so odd. I will be out of town for a week, so when I get back I’ll try to pull the Cat off and see if I find anything. I am totally stumped here though…:hmm:

Ranger
02-10-09, 12:24 PM
If the CAT where plugged I'd expect it to be worse at higher RPMs.

codewize
02-10-09, 01:32 PM
Agreed, that doesn't sound like a clogged cat. My Brougham did that and I said the same thing about hi RPM's and it did turn out to be the cat but it was never consistent.

Mine was all over the place, never the same, and it wouldn't always do it. I could go for a week running fine then back to bogging. The other thing is that I had intermittent lean codes, and O2 sensor codes when the cat was clogged.

I also agree that it sounds like either a PCM issue or something to do with electronics. I'd still check the cat or have it checked just to be sure but that's certainly an odd one.

BlackCaddy87
02-10-09, 03:07 PM
my yota was the same way...i could be cruising down the interstate in 5th gear then all of a sudden work my way down to 3rd just to stay with traffic to get it off the exit. sometimes i couldnt go over 40mph

Aurora By Olds
02-20-09, 06:05 PM
So I took the chance and checked the CAT. It's wide open. I am about 100% convincecd that it's a software issue dealing with the PCM. I assume sending it off to have it flashed (maybe performance upgrades done too) would cure the situation. And ideas or recommendations?

Submariner409
02-20-09, 08:22 PM
A GM dealer can reflash the PCM if necessary. There are no "performance upgrades". Period.

IF the Aurora uses a semi-drive-by-wire TPS, then that might be a place to look. A slow TPS/butterfly can cause all sorts of nasties.

(Oh, its not an Aurora....its a Cadillac........)

Dadillac
02-22-09, 10:53 AM
MAP sensor

Don

Aurora By Olds
03-06-09, 10:15 PM
MAP sensor

Don


Quite possibly now. Finally got some codes today. Still havent had any time to deal with the issue, since the car still moves. Got "traction off, service transmission" message today as I was roddin on her a little bit. Checked the codes, and got all of the following codes in the history. Only the trans code was current, which cleared up after a simple restart:

U1016 - Loss of Class 2 Communication with VCM
U1016 - Loss of Communications with PCM
P0108 - Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage
P0731 - Incorrect 1st Gear Ratio
P1106 - Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent High Voltage

Is there any way to check the MAP with simple methods? What about unplugging it and seeing if the results change my consistent problem at all? Any ideas? I would take it and have it flashed, but I really dont have the time or ambition to sink into this thing. Plus, I am thinking the MAP may be a possibility now...By the way, anyone wanna buy it? :rolleyes:

Dadillac
03-07-09, 03:37 PM
My car did the same thing a few years back. Got a new MAP sensor and haven't had the issue since. About $50 if I remember right from www.gmpartsdirect.com.

Don

Aurora By Olds
03-17-09, 01:20 PM
MAP sensor did it. Thanks for all of the input.

Dadillac
03-18-09, 12:22 AM
MAP sensor did it. Thanks for all of the input.

Glad I could help

Don