Recently I added a 150 shot to my car and it began to sputter in the higher RPM's. It feels almost like someone is hitting an ON and OFF switch when the Nitrous is activated. I did a WOT run all motor and the car did not sputter.

Any thoughts on what it can be? I was told I would be pushing the stock fuel pump to its limits, but I'm not sure how to know that without any tuning software or stuff like that.

Thanks

 

Are you logging these runs? have you been to the dyno and checked the A/F while you are spraying the car? I going to guess that you are running WAY lean and detonating. I would not spray the car again unless you have it hooked up to a wideband. you could be in more trouble than you realize

 

If ya have a FPSS try by passing it and try a run again. Prob the #1 cause; fpss out of adjustment.
Robert

 

The car has had a small tune to set up the nitrous, but I haven't had an actual pull on the dyno. My tuner told me it was on the safe side but should be ok.

I told the shop who installed it to put a FPSS, but everything is loomed so I have no idea what or where to look for it.

I have ran a bottle already and didn't have any problems.

 

if you ran a bottle through it and have not gotten the p300 random misfire by now then you may have other issues. Roberts correct about the FPSS. I personaly dont use one. I still recomend taking the car to the dyno for a couple passes to verify the A/F after you get the FPSS removed or reset.

 

You may have just reached the cusp where the fpss is coming on and off, maybe just a filter getting clogged? You really need to get it sorted out. Check any of the vendor sites for a fpss, then look for yours. Then you can just take a jumper wire and cross over the two terminals, or just hook them together on one post. The fpss is just a sw, and bypassing it is easy. If this cures the problem then we can address adjusting it correctly.
Robert

 

I went out to check the connections on the car, took off some of the loom and I don't actually see a switch. But again, not entirely too sure.

I have good bottle pressure.

I recently swapped out the fuel filter and a few other things because I did have a random misfire code, but the code was there before the Nitrous. So I put in new plugs, o2 sensors, and checked the wires. Everything looks fine from that end.

I'm gonna have to get it on a Dyno

 

Mine would sputter when the timing was off. I was either pulling too much or not enough. I have it sorted out now and it hasn't sputtered since.

 

Have you heard of a problem with the walbro and the fpss? I thought i saw some guys having issues with them.