I have had this issues for about 2-3 year now but no one know what the problem is or have it replicated.

IT always happens when cold. Car will start up fine some times the revs may drop and cut out. When i start to drive the car it starts sputtering and won't go anywhere almost come to a halt sputtering real bad( i have my foot flat on the gas). Then all of sudden it would kick in or like it just got a surge of fuel and shoot off. This can be dangerous because when just start my car and pull out in traffic i am not sure if it is going to sputter and won't go any where. Once warmed up it is fine. I am not sure if it is ignition or even my Fuel injectors that can be causeing this problem. I have asked this question on here before an no one could help me may be some one can help me now.


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

Oh yeah i have change spark plugs, fuel filer, oil is changed regularly, change the wires from teh Coil packs.


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

If it was the fuel injectors it would be having the problem the whole time the vehicle is running. Is the Check engine lite on?

my trans am did the same thing when it was cold (like 40 or below) but it would go away if i let it idle for like a min.


-Borsty

It does it more in the winter but i am in Florida our low is 29 degrees. It happens in the summer as well. Some times it happens in the summer and even if the car has been idle for a while. On occassion it has done it after waiting at a red light.


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

I am having the same problems and I have narrowed it down to either fuel pump which I doubt....or the first 02 sensor. Its been doing it before and after I put a new motor and s/c on my car.....I'm changing the o2 today so I will give u an update if it helps or not....




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I put on a new Cat back and i have two new O2 senors in place and i still have the same problem. So that is not a fix. I hope it is not the fuel pum because that can be an expensive job.


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

Mylife75 wrote:I put on a new Cat back and i have two new O2 senors in place and i still have the same problem. So that is not a fix. I hope it is not the fuel pum because that can be an expensive job.

strange...my car's been doing this occasionally (not during cold weather) since i got it

I dont think anyone have really figure this one out. I have the same problem.. just happens after start up for couple of minutes. Then it goes away. only happens again when the car sits for a long time and start it again. It happens to me when its hot or cold. I also live in Florida. If you want to read more on it, search for Hesitation, cold start, rouge idle, etc...

Someone said there was a recall for this but only 1 or 2 people said they did it. Dunno but if you figure it out, let me know

Mine's been doing the same thing, except not quite that bad yet. (I have a post in this forum called "Car Possessed?") (No CEL here, maintanance done....)

I just got off the phone with the mechanic, he said it's more than likely the TPS or fuel pump.

I'm praying it's the TPS... much cheaper fix... but if it's the early stages of my fuel pump going... then I suppose I must fix. Car has 154,000 miles on it... maybe it is my fuel pump?? Let's pray it's the TPS.

I'm getting a whole new sending unit for the fuel tank courtesy of Shell gas being bad.....So after that is in and if its gone then I guess my problem is the fuel pump....If not then I'll try a new tps sensor and see if that helps...



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Bobby wrote:I'm getting a whole new sending unit for the fuel tank courtesy of Shell gas being bad.....So after that is in and if its gone then I guess my problem is the fuel pump....If not then I'll try a new tps sensor and see if that helps...

The fuel pumps sounds like a good guess to me. It sounds like you are running out of fuel under load. Check fuel pressure and flow. Pressure is easy to check with a gage, put flow is a little more advanced. You need a low amps clamp and graphing meter with wave form. Set the meter to waveform power controlled and set the rage to 1v to negative 0.2v. Set your time to 10msecs. You will have to jump your fuel pump at the relay with jumper wirer. Pins 87 and 30. Set the low amps probe to 100ma.

Your wave form for a good pump should have 6 to 8 commutators, you will see these as humps on your graph as the amps osculate. you should find two identical humps 5 or 7 humps apart. this is on revolution. you should have at lest 1 rev per 10mSecs. Then you could do the math to figure out the RPM. Your graph should have clean osculations.

This is better to have done by a profession because they truly know how to read their meter.




1979 Impala Sport Coupe Aeroback

what oil are you guys running, cuz my car started this same problem when I changed it to synthetic oil, could this be the problem?

my car has been having the same problem a lot lately too, today i pulled into a parking spot and the rpms went to 1200 then to 500 about 5 or 6 times, the engine was at 190 degrees and it was about 40 degrees outside, it doesnt do that often. it has also happened when trying to accelerate and the car just acts like im not even pressing the gas, it has almost caused me to get in an accident someone needs to figure out what it is because it can have serious consequences for someone

Quote:

what oil are you guys running, cuz my car started this same problem when I changed it to synthetic oil, could this be the problem?

It's not the oil.....Before I put my new engine in I was runnin regular 10w30 and it was still sputtering.....Now with the new motor im runnin 10w30 Synthetic and the same thing is happening

My car just threw the 02 sensor code again so I'll change that and i'm changing the



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funkz24 wrote:it has also happened when trying to accelerate and the car just acts like im not even pressing the gas, it has almost caused me to get in an accident someone needs to figure out what it is because it can have serious consequences for someone

It almost has i was pulling out on a major road when it did that and i almost got hit. This can be a serious may be deadly problem. i have changed all that i can on the car except the fuel pump, coil pack and injectors.

Also my car also does the rev jumping thing. It will rev up and drop down and rev up and drop down between 900-1800 RPM. I am not sure what is wrong.

What i do know is that i just recently put a grounding kit on my car and although i have still the problem it is not as bad as before i still need to drive my car to see if the grounding kit has helped


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

take it to a professional.




1979 Impala Sport Coupe Aeroback

I have taken it to a professional so many time and they say they are not sure what it could be and they weren't able to replicate the problem and there are no code so the computer wont tell them anything.


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

I have a '96 Z24 (bought it new in April '96) and for the past 4 years my car has had the "hesitation" after cold start problem. Basically after I would start it and go to speed up the engine would almost die, and sometimes would died. After a few seconds it would return to normal and be fine. Over the years I changed most of the sensors, plugs, wires, fuel filter, etc. In 2001 my battery died so bad I could not even jump it off. I noticed that after the new battery it did not do it for a while but it eventually came back.

Last year my battery died again. I could jump it off but it wouldn't hold a charge. Same thing happened with the new battery, the hesitation suddenly went away. A few weeks ago it started to come back a little again. Then it hit me, it must not be making a good connection somewhere, and slowly killing the battery. I replaced the whole ground wire assembly with a new 4 ga. one. The old ground wire was brittle and corroded where it connects to the battery shelf and engine block. It has not hesitated once since then and seems to run better.

You may want to try this, the ground cable was about $15 at advance auto. It was a direct replacement and was hanging right there on the shelf. Made me think that they sell alot of them. Hope this helps, hopefully this problem won't be back.



Captain Bay 3000
'96 Z24
'04 Titan

Actually to update. I purchased a grounding kit and the car seems to be doing better it has not completely resolved it but it is doing better.


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

You may want to check the positive cable from the battery too. I am thinking about replacing mine for the heck of it.



Captain Bay 3000
'96 Z24
'04 Titan

****Update to everyone w/ this problem***

Today I changed out my ignition control module...the little circuit board thingy under the coil pack cover......and the sputtering is gone completely.......

So if any of you having this problem haven't changed that then try it.......





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It is the ignition coil module. That is what i see on GMpartsdirect.


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

dang is cost $166.00 including shipping


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

No its the electronic ignition control...part# is 10487716 on gmpartsdirect.......u can look it up on there and there is a pic of it too....



Car is for Sale!Supercharger kit is for sale!