No spuddering when cold...Until it warms up.. HELP!!

[phillabaum03]

Im having problems with spuddering very badly. Like i cant almost make it up hills. If i gradualy give it gas and dont boost. I can take it to 7000rpms no problems. Untill i give it somemore and it starts to boost it spuddders very badly. I took my car out this morning after it sat all night and went down the road. As soon as i started the car i opened it up. No spuddering..Pulled hard. But as soon as the car started to warm up it started sputtering again. WTF So doesnt spudder when the cars cold but as soon as it starts to warm up it spudders badly. There no cat on the car, new plugs which are the proper ones and gapped properly. O ya and its a 6 bolt in a 96 gst. No known boost leaks..Check engine light for rear o2 sensor.

 

[phillabaum03]

Come on guys.

 

[playitlouddsm]

So it only does this past 7000rpms? Are you at wot or part throttle? Do you have any fuel mods?

 

[SixBolt_16G]

Ive got a 6bolt in a 2g also.. Are you familiar with random misfires? Kind of sounds like what my car was doing, before i did the pot mod.. You might want to do a search on Random misfire so you can rule that out as the culprit if you havent done so already.

 

[phillabaum03]

The pot mod? At wot it studders. It doesnt it do it if just gentle give it gas but if i go to 1/2 thorrotle is does it. No fuel mods. Totally stock besides the 6 bolt.

 

[phillabaum03]

Hello anyone? could if be the EGR? Fuel pump. Im open to options.

 

[19Eclipse90]

1. Make sure it is correctly timed with the cam angle sensor.
2. Check plugs and wires
3. Check connection to coil
4. Fuel filter, injector flow, or pump
I had a s-st-st-stuttering problem with my GS, the cam angle sensor wasn't right and fixing it helped a lot. It also had cheapo spark plugs and wires so I threw some NGKs in it and that helped a little. The fuel filter was changed and that didn't help much. It has the stock injectors and maybe a replaced pump with 188K miles. Just some stuff you might check.

 

[phillabaum03]

Im not exactly sure how the cam sensor works. I know you need a timing light and i dont ahve one. A guy did the timing and it ran fine. I dont think i could of moved.

 

[phillabaum03]

What would be the difference when its cold and when it warms up?

 

[19Eclipse90]

What would be the difference when its cold and when it warms up?

I don't understand that either, but it's what my GS did, and now it's been fixed, I haven't noticed the studdering in a while. If you feel confident that that is not a problem, move on.
Does it throw any codes when the problem begins? Does it use ungodly amounts of fuel while studdering?
It sounds like it's going to be wise to start with the fuel system. When was the last time the filter was replaced? Most any automotive repair shops can test the flow of the injectors for you, so that shouldn't be a problem. Then you are left with a fuel pump which, hopefully you planned on replacing with a 190 or 255 anyways .

 

[BOOSTJUNKIEGSX]

Hope this might help.. I had the same problem on my 97 gsx. I have a big 16g, 6-bolt with 550`s and 255lph 20psi... I could start my car letting it run for a min or too and when i floored it it boosted really goood, When the car warmed up and i boosted it would stutter all the way to 7000rpms in and out. Solving my problem i added more fuel and the car ran GREAT!

Good luck!

 

[phillabaum03]

Such an easy fix. New plugs and she runs like champ. These damn DSMs. Thanks for all the help.

 

[SixBolt_16G]

Plugs? Thats it? In the orginal post you said you already had new plugs.. One of them was bad i take it?

 

[phillabaum03]

I mean plug wired..oops