Paxton Viper, when doing a pull it's not smooth but has slight hesitation...

[KDR83]

Finally getting used to my "new to me" Viper's power so starting to get on it a little more. One of the things I noticed that when I do a 3rd gear pull since that is the first gear that I can actually get traction, the pull isn't completely smooth but feels sort of like the car is misfiring/hesitation however the plugs are brand new so I doubt that is it. The only other modifications besides the paxton are a corsa 2.5 inch exhaust and DC reflash tune instead of the paxton piece. Any idea what may be causing this, I think the plugs are just new stock ones, can that cause it to misfire, do I need different plugs? Any direction would be helpful. I want to make sure not to harm the motor, thinking about purchasing a PLX DM-6 gauge so I can set an alarm for if the car ever goes lean at boost.

Thanks

 

[Ghoust]

Although this would probably not fix the issue, if you have stock platinum plugs on a paxton car, I would highly recommend switching them out to copper as you will want colder plugs on a boosted application.

 

[Nine Ball]

If you are still using the two external Paxton fuel pumps and the FMU, that is likely the source of your problem. Mine used to do the same thing, it would have some hesitation and slight bogging when those pumps first kicked on, and then smooth out at higher rpm once the tune caught up to the fuel pressure spike.

The only way to get rid of that is to do a completely new fuel system front to back, getting rid of the auxiliary dual pumps, and going with proper sized injectors. This fuel system also makes it much easier to tune with SCT software, not having to deal with the Split Second Paxton controller.

 

[ViperGeorge]

You should be using the NGK V-Grove plugs (don't remember the number but Dan at DC Performance can tell you). The gap should be closed down a bit as well. You could be getting spark quenching. The boost basically "blows" the spark out and causes incomplete ignition or worse, a misfire. Had the same problem with my Paxton 06. Changed the plugs and got DC Performance to flash my PCM with their supercharge tune. Also lowered thermostat and added a high flow pump on the intercooler.

 

[mjorgensen Woodhouse]

Take it to the dyno, you will find out what is causing it and what the A/F is doing before you hurt something, never guess... everytime you run it lean you risk a much costlier situation then a dyno pull or three.

 

[speedracervr4]

I would suggest on taking it to a dyno or doing some data logging to see what the cars doing as far as A/F ratio,fuel pressure, ect..

 

[speedracervr4]

oops..didn't see woodhouse's post.

 

[Nixon's SRT]

Call Doug Levin at DLM. Talked to him over the phone and few times, he walked me through some troubleshooting and parts to look at and I was able to fix my issue.

 

[ViperGeorge]

Call Doug Levin at DLM. Talked to him over the phone and few times, he walked me through some troubleshooting and parts to look at and I was able to fix my issue.

Yea, what he said. Doug helped me a lot too.

 

[Paul Hawker]

Always a good idea to consider plug wires too.

 

[KDR83]

Thanks for all the responses, I will look into the plugs first because it sounds like they need to be changed for the correct ones anyhow.

 

[KDR83]

Also what plugs are recommended, I saw some plug that was highly recommended but it appears it has been discontinued

 

[Nixon's SRT]

NGK 4291 / ZFR6F-11 gapped at .032