sputter under boost

[Andrews93gsx]

Hey i just put my new front mount on its the VR speed front mount. i put it on and now my car is sputtering out at about 4.5 rpms. it pulls hard until then. i changed the plugs out with ones i had already. i just put new plug wires on. i have a 16g but have just at 10 psi. until i get my datalogger in. but it was backfiring... i am confused and have been trying to figure this out the last 2 days. it does it under high rpms in all gears. any input would be greatly appreciated. im getting irratated thanks in advance. also i still have all emissions should i remove them maybe one of the stock vacuum lines broke. idk anymore....

 

[agentorange313]

I think your timing is being retarded by the ecu.

You will know backfiring, you def would feel the immediate need to shut your car off.

Did you just replace the wires or the plugs also? Might want to try the plugs.

IDK why this happens but when installed my FMIC on my 14b setup (stock system with a FMIC in a 1g) I had the same issue. I didnt know why my car was doing that but it I didnt really care because the same day I installed ecmlink and never had the problem again after some tuning.

Also check you knock sensor.

goodluck

 

[Killa_dsm]

I would do a boost leak test, also what kind of plugs and what gap are you using?

Boost leak tester:
IC Pipe Tester

 

[SD99GST]

I had a similar problem like that about a month ago, was skeptical about it being my plugs just seemed to easy of a fix for me but my friend insisted it was the case, 4 plugs later... problem fixed. For the price of the plugs I would start there. Good Luck.

 

[juanpac0]

You have a boost leak, all else the same the only thing you touched were the intercooler pipes - which would lead to a boost leak.

 

[Andrews93gsx]

So i have some new info. a couple of days before i got my front mount installed my car would surge when coming to a stop light when idleing and then go away after 3 quick surges.. but i dint look into it then. i hooked my intercooler up and it was still there. i figured it was a boost leak.. i havent run a boost leak test yet but im almost positive there isnt any major leaks.. so i looked more into wires and all my sensors and the coolant sensor with the two wires which is the one for the ecu had a wire broke off. but no code came on until today. i read it with my datalogger and it was code 21 coolant temp sensor. my car will surge until its warmed up and then go away... could this also caught sputtering and hesitation under boost? since that sensor affects air/fuel because the ecu isnt reading the right coolant temps?

Sorry if im askin stupid questions i been trying to read up on this more and more but havent found the best info... also what is the part number for the sensor i have went to oreillys and autozone and they give the wrong sensor to me. They gave me the one with the two spades shaped like a T thats in the lower thermostat housing instead of the one in the upper left of the housing. They tried to find the ecu one but cant find it. Thanks in advance.

 

[Indian]

This sounds more like a boost leak. You might want to loosen back up all the clamps and see if you can push the piping further into the coupler,and then re-tighten. When I had a boost leak, the coupler was sitting at an angle,and the piping was barely pulled out of the coupler. I could barely tell it was even there.

Also for the surging, Try pulling out your ISC,clean it, and install a new o-ring. Boost leaks also cause surging.

 

[Andrews93gsx]

I pulled the couplers apart and re tightened them many times like 10 times still same.... the pipes all are in the couplers.. and i have the short route so there is only one pipe for each side... its got me stumped... Could that sensor and check engine code 21 have anything to do with it tho.... ### i think i broke that wire all the way off the connector when i hooked my new intercooler up. i saw them before and they were cracked and brittle. and my boost gauge seems to stay at 11 psi pretty good. but seems sluggish getting there. But tomorrow i will go threw the pipes again for the 11th time...

Tomorrow i may make a boost leak tester to really figure out the boost leaks... im kinda scared to do this i will probably find many i dont want to. but it will pay off after i get it done.

 

[Jesse__c]

fix the wire and see if it helps.

 

[Andrews93gsx]

i fixed it yesterday but the sensor still threw a code. so im sure the sensor is shot. and autozone and oreillys seem to have no clue about that sensor. they just know about the other two. one for the gauge and the one for the fan. And not the one for the ECU.