I just got a synapse waiting for it in mail. I also have been getting random cylinder misfires and recently a cylinder 4 misfire. I wonder if it's related to my injectors...

 

Bump

 

I have this same problem but like previously posted, its random.

 

Many times the issue is with the IAC or something else mechanical, with that said it's possible it's in the tune itself. There are a lot of idle tables, cams can cause it, fuel trims being off, the PS switch being bad etc.

 

Ps switch?

 

Yes, there's an electric input to let the ECU know when the power steering is under load. Single wire that comes off the pump.

 

So then my next question would be is there a way to tune this out or do you just have to replace the sensor to get drivability back(well pump since you can't buy sensor alone).

 

He said it could be multiple things im pretty its the iac, alot of threads comment about this because the gears are plastic

 

Have you talked to your tuner? It's probably in the tune, but I've seen brand new FIC's have problems. It's rare though. I'd have your tuner try and fix it and if it can't be resolved then it may be the injectors.

 

No it's not iac I have evo 9 which has metal teeth and I have already tested mine, it is good according to ohm, visual inspection of valve movement and disconnecting and watching my rpm go insane( don't trust one test). On the other hand my ps pump is completely missing the wire altogether. It works fine but I was wondering if you could tune that read to be mimicked good like we can with the rear o2. But I am in the process of sourcing a new one to test that possible cause as well as preparing to swap in an aeromotive fpr and rail. Op I will replace each part separately and see if one leads to a fix in my car to give you a possible fix to your issue.

 

Thanks Jason. I think I'm gonna try to buy a used known good iac and see what happens. I read something about a few people having iac pass all tests and they replace it anyways and it fixes the problem. I'm more weary because my car only has 25k miles.

 

Yeah I hear ya mine had 54k when it blew its first engine and I've just been trying to get the new one running right since. Good luck with the new iacv hopefully that fixes it just post your results and if you have luck maybe I'll try mine as well, and I'll post my results in case that doesn't fix it or if someone else has the same problem later on and find their way to this thread it might help them. I hate finding threads with my problem then no final word on if it fixed their issue or not.

 

Ya will post once I find a iac and install. Thanks for all reply. Would like to add my biss screw had a leak and I replaced screw and o ring and cleaned tb, maf, and iac and no difference.

 

Ok got the new adjustable fpr in and finally tested it after I fixed the studs on my coilovers (broke one putting strut bar back on and apparently another on was stripped and no way I'm driving my car with one stud holding my coilovers on) But didn't fix the idle drop issue, but did fix a couple other things which was a little odd. Hoping to do the fuel rail this weekend once I get the new O-rings from stm (doubt that will effect this but I want to replace injector seals and mind as well put the ams fuel rail on that's just been sitting with the rest of the extra parts for a year haha). The new ps pump should also be here this weekend or next Monday so I'll update after I get that in and connected.

 

Waste of money putting an adjustable FPR on an EVO….