Missfire under boost?

[AtlanticGSX]

I swapped from a stock turbo to a 14b this weekend without a tune. I ran it easy for a while to make sure I had no leaks etc, but under boost(10ish)psi, and up around 4500rpms, I have a big missfire. I have slacked the gas as quick as possible afterwards, to try to prevent any damage. I was just wondering if anyone has had this trouble, and what it might be that is causing it? I run pump gas, and the car seems to be running really smoothly after my swap. This is the only hitch I have had. I appreciate any advice on this, and I do plan to take it somewhere and have it tuned, but would like to have this fixed before hand.

 

[Ballistik2G]

Just sounds like a small boost leak

 

[CardShark]

A 14B on an otherwise stock 2G is not going to cause a misfire like you are describing. Your problem has nothing to do with your swap unless you didn't tighten something and you have a large leak.

The first thing to check is your plugs and wires. Get a new set of NGK BPR7ES plugs (gap at .028) and replace your wires with some NGK ones if the ones you have are old.

 

[94_TSi]

The car doeant need to be tuned if all that was done was you swapping from a stock turbo to another stock turbo. Do a boost leak test.

 

[Tanro]

Boost leak test, NGK BPR6ES @ .028, new plug wires if yours are old. Again NGK are great. If not the Accel Thundersport wires are very good as well.

 

[NightRiderSRT4]

NGK FTW. deff check for plug/wire issues....it is the root of most of those misfire issues. a lot of people think it is fuel cut or overboost, but in your case 10psi shouldnt be doing that.

 

[AtlanticGSX]

Hah! So I was heading down the road today, not even under much boost, around 4-5 psi. All of the sudden my car just dies. I was unsure what it could be but I pulled over and popped the hood. I look it all over then something catches my eye. The pipe from my inlet on my intercooler has let go and my car is being starved of O2. As it turns out, i put the hose back on and limped to the local garage, bought a couple good hose clamps and fixed my problem. Coincidentally I also found my Pressure leak. No more pop under bigger boost. Thanks for all your advice. I will get the plugs/wires soon and put those in as well. I have an FMIC coming this week, probably do it all at once. I haven't looked at the local garage, but just in case they don't carry 2" rubber hose, whats the best place to buy some for installing my FMIC? Thanks again fellow Tuners.

Bob

 

[TJCTalon]

i just went through the exact thing your describing my friend.

This is how i fixed it. I found a major boost leak. I also changed my plugs and wires. My car is running better then ever. So do a boost leak test and change out the plugs and wires and you should be golden.

If that doesnt work it is probably sensors on your throttle body. My buddy had some cut outs/hesitation in boost and we swapped his tps and it fixed it.

 

[Ballistik2G]

Sweet! Glad we could help.