So here's my problem at idle the car seems to have a weird sputter/ miss. This doesn't always happen at the same time so I've tried to rule out a internal engine problem I've talked to unichip n they seem to think its in the idle map. So I tried letting the car run off the stock ecu n still the same problem ( keep in mind I never reset the ecu) with using my larger injectors not stock ones I thought it was a miss so I've already replaced plugs checked my injectors replaced the o rings n the isolators the car runs fine under boost with a 10.6-11.2 afr with the unichip plugged in I get a short trim is about 6% long term 3% . Crush chime in whenever need be lol. So u know also running 630cc moroton (sp) injectors

 

hmmmmm....tough one...fuel trims sound great.

are the injectors pnp or spliced in with pigtail? check connections to em if you havnt already.

now the fuel trims you posted are they at idle when your having these issues? when you feel a mis what are the fuel trims doing? dos the fuel trims change at/around the mis? what does your ign look like when the mis happens? any codes? is primary o2 sensor in good health?

could try swapping out with a friend o2 sensors, its quick and easy and will rule out o2 sensor being damaged/fouled. Kinda doubt its o2 sensor cause your fuel trims look good but its still worth looking into.

what plugs are you running (part number if you have it)

has it always done this since boosted or is this a recent issue?

any possible boost leaks?

 

if possible post a vid of this mis

 

The injectors have been spliced in. They were soldered n tapped like factory. Fuel trim readings were at idle. Fuel trims to change when it misses 02 looked fine when I installed it. Was white but other than that it was ok. Only having problems sitting still. While driving the car is on the money. Stepped on my scan tool so I can't tell u ign specs but I'll have one back by this weekend running one step colder ngk. Don't have a on but this also happened when I was on stock plugs. Idk of any boost leaks

 

Watching this........ Have the exact same issue with my t-netics kit. Have yet to figure it out. Guessing its a uni-chip issue trying to control the larger injectors at idle. My idle is always good, no cel's, fuel trims around 0, and no drive ability issues. Probably wouldnt notice it if I didnt have aftermarket exhaust. You can hear the spudder at the tail pipe and the motor will slightly shake. AFR at idle is steady 14.7. It's annoying but I figured I would get it figured out when I get tuned. Good luck and let me know if you figure it out.

 

whats your idle afr street? I assume its around 14.7 but want to make sure.

 

btw i dont tune the unichip so i really cant get too deep into tuning aspect of it. it doesnt sound tune related though. its going to be sensor issue, vac leak, wireing, or mechanical issue.

just for grins do a comp test.

 

oh and hook us up with a vid of this mis

 

Streetsweeper, Your saying you completely took out the uni-chip and your car started up and idled with 630cc injectors? Also did you have the issue as soon as the install was done? I think in my case and yours that possibly an injector isn't being told to fire when it should. I'm gonna ohm check mine....you should do the same and we can compair. I'm guessing your have zero miss fire codes also...right?

 

any updates on this?