: Severe lack of performance



Dadillac
01-04-05, 12:22 AM
Here's one for the guru's. I went on a ride this past Sunday, to do a few errands. I came up to a stop sign, on a road, that entered onto a state highway. Since traffic was very light, I figured I'd have a little fun. I waited for traffic to clear, and I slammed the throttle down. What happened next, really worried, and angered, me. I slammed the throttle, I heard the intake gulp a large amount of air. The Northstar stumbled really bad. I decided to stay in the throttle, to see what would happen next. The car started moving, but at a four cylinders pace. I could have ran faster than it was accelerating. It wasn't making any strange noises, or blowing any smoke. It took about 1/3 of a mile, to reach 55 mph. Once it hit 55, whatever was happening, cleared up, and she took off like a rocket. Upon leaving the highway, I tried to get the car to duplicate the problem. I would slow to almost stopped, and nail the gas. I would here the large gulp of air, it would hesitate, and then take off. This morning, and afternoon, on my daily trek, to and from, work, it responded fine. What happened? I am guessing TPS, but if it is the TPS, why would it happen, and then not happen? Help.

Don

sts96
01-04-05, 08:01 PM
My guess is engine not up to full temp. summer blend gasoline= partal flooding with fuel, should clear up as gasoline blend changes to winter blend . lol sts96

danbuc
01-04-05, 09:53 PM
It is winter right now. Its January 4th.

an01sts
01-04-05, 10:41 PM
We later model Seville owners probally say that's werid. Maybe other people can put thier .02c in, but I have never done a wot off the line, meaing from idle to full throttle--you know! BANG!

Do you play around with the car, or are you one who does those Yugo starts?

The reason I ask is that off the line, the most gas I can give it is maybe 1/4 throttle, without breaking traction. It might not even be that much. For had launches I ease it quickly to the floor. It's kinda' like holding your mouth right when you do it.

I know that any more than the about 1/4 throttle, it just sits there and rolls the rubber off the tires, so I have never flat-out nailed from idle, assuming that it would just sit there and white smoke the tires.

I'm wondering wheter or not this is a case of loading up the engine with too much gas. What is other Seville owner's experainces with flat-out nail from idle?

You have my couriousity going, and I'm half tempted to matt it off the line--just to see what happens. Well, I'm only half tempted cause the g/d sneakers for the car are brand new and they are major horse pills to swallow then they show you the "amount due."

Okay, Seville owners, do they sit there and white smoke or do they load up when you matt 'em from idle?

Dadillac
01-04-05, 11:02 PM
Okay, as far as the engine temp, it was completely warmed up. Here in NJ, we already have the winter gas. I have been playing with this car since I bought it. I attempted to do some 0-60's several weeks back, but couldn't get the feel for the throttle and kept lighting them up. So on Sunday, I said, what the hell. noone is around, I have open highway, let's shread some rubber (my tires are new). I floored it, and nothing. I probably should have backed out of it, and then stepped on it again. That probably would have fixed it. I am not someone who usually abuses my vehicles, but sometimes, you just gotta do it. It actually felt like I had a 850 double pumper, on a stock 350. Except, it took a long time, to clear itself up. I would really like to know what happened, but if i don't find out, no biggie. It isn't happening now. But, I will try again.

Don

danbuc
01-04-05, 11:08 PM
If I just put my foot to the floor, the tire will spin, but they won't smoke. The Toyo's I have now get pretty good traction which might be why. I have never had a problem with the car stumbling over itself when giving it full throttle. Usually, I here a screech and then get sucked into my seat for a bit until I let up off the gas. Not sure what your problem could be, if it was flooding the engine, you would probably see some smoke coming out the back of the car from unburnt fuel. Good Luck. :thumbsup:

haymaker
01-05-05, 12:54 AM
I wonder if it is a traction control issue? One wheel is turning much faster than the other causing the pcm to back some spark timing out of the engine. I have had mine do that on ice, the traction control engaged, pcm backed off the spark timing, the car just rolled on at a slow pace until I backed off the accelerator, the traction control disengaged and once again then the car accelerated normally.

BeelzeBob
01-05-05, 01:22 AM
I smake the throttle open all the time off the line and it works fine so that is not the problem....

My guess is that the traction control was turned off (maybe...???) and you got into some wheel spin that activated the differential protection mode. The traction control is designed to protect the diff from high differential wheel speeds (like one tire spinning and the other not) and when it is turned off there is a remedial protection for the diff that will kick in if wheel spin on one tire is excessive.

That is the only reason I could think of for the engine to stumble like that. Try it with the traction control on and see. The traction control will allow the correct amount of wheel slip for optimum acceleration (it is not nearly as intrusive as the traction control systems on rear wheel drive cars) so just smake it open and hold it and let the traction control work.

haymaker
01-05-05, 01:33 AM
I smake the throttle open all the time off the line and it works fine so that is not the problem....

My guess is that the traction control was turned off (maybe...???) and you got into some wheel spin that activated the differential protection mode. The traction control is designed to protect the diff from high differential wheel speeds (like one tire spinning and the other not) and when it is turned off there is a remedial protection for the diff that will kick in if wheel spin on one tire is excessive.

That is the only reason I could think of for the engine to stumble like that. Try it with the traction control on and see. The traction control will allow the correct amount of wheel slip for optimum acceleration (it is not nearly as intrusive as the traction control systems on rear wheel drive cars) so just smake it open and hold it and let the traction control work.
Mine does it every time on ice, wet roads and the traction control is on.. I can nail it as hard as I want and the car goes into slo-mo until I back off the gas and ease into it again.

Dadillac
01-05-05, 06:05 PM
I first thought that it was the traction control, but I don't think so. Everytime the TC has kicked in, the DIC displays a message. I never turn off the TC, so I am sure it was activated. While this was happening, I was checking the tach and speedo, and if the TC message was displaying, i would have seen it. Since I didn't hear any wierd noises, see any smoke out the exhaust, or see any messages, I assumed it must have been some type of a sensor issue. And that is my downfall. Since all of the computers, and sensors, have made thier way onto cars, I haven't kept up with thier operations, and so forth. So, when an issue arises, I diagnose in an old-school way. Unfortunately, that way rarely works any longer.

Anyway, the car seems to have gotten over it's little hiccup, and it is running fine. Once the weather clears up, I will attempt this again. If it does happen again, i will dig into what the problem is, and repair it. Thanks for everyone's input, it is much appreciated.

Don

BeelzeBob
01-05-05, 08:20 PM
Were you on some questionable traction pavement or ice and snow when that was happening??

I drove home tonight on ice and snow all the way and floored it from every intersection and the traction control kicked in nicely, inhibited wheel spin, the engine dropped back to 3 cylinders due to the slippery conditions and the car just gently crawled away from the lights as fast as the ice and snow would allow. That is how it is supposed to work....

an01sts
01-05-05, 09:25 PM
Maybe it is a traction control issue. As we know, the car defaluts to t/c--most t/c cars do--so you cannot have t/c off unless you intentionally disable it.

Way back, I played with turning off t/c for off the line launches. (I read that the car will start in second with it off. Maybe on lighter takeoffs, it starts in second--I have no clue--but my car starts in first on hard launches with t/c off. I spent some time playing with t/c on/off and know the difference between first and second gear.)

The reason I was playing with t/c off launches is that I have had t/c foul up launches. It kicks in, and dogs down the car. Against a ricer, it isn't a problem, but if could be a problem against something with more meat under the hood.

I didn't see where t/c off helped anything on hard launces. If you break traction, you're loosing time, so the trick is to find the sweet spot.

I'm about tempeted to matt it--with t/c on--just to see wtf it does. Anybody got a pair of sneakers I can borrow--just in case?

Dadillac
01-05-05, 11:43 PM
Were you on some questionable traction pavement or ice and snow when that was happening??

I drove home tonight on ice and snow all the way and floored it from every intersection and the traction control kicked in nicely, inhibited wheel spin, the engine dropped back to 3 cylinders due to the slippery conditions and the car just gently crawled away from the lights as fast as the ice and snow would allow. That is how it is supposed to work....

It was sunny and fairly warm here in Jersey on Sunday. So, road conditions were very good. Highway was dry, although a little salt covered. I was accelerating, from a stop, with the wheel, cranked a bit to the right. Not too much, but it wasn't straight. Correct me if I am wrong. If the car looses traction, and the TC kicks in, a message pops up on the DIC, right? I am assuming this occurs, everytime, the TC is in operation. What really confused me, is that the problem, once I got to about 55, just went away. Almost, like there was a fuel line blockage, that suddenly cleared itself. No messages, no signs, nothing. Just a huge dog. Thanks to all again.

Don