Hey all,

My car is a s5 t2 running a n370ecu with the cosmo map and afm. Im using a FBCD and running 8psi with 800cc secondaries. No emissions.

The issue suddenly happened when I was driving my car home after filling her up with gas. I was going about 45mph and then the car just started bucking and lost all power. It dropped to about 200rpms. I turned it off and back on and it was back to normal, but it suddenly lost power again. I made it home and turned the car off then back on. It was 'normal' again and idled for a good 10-15mins no problem. I have no vacuum leaks according to my boost gauge. I took it for a short drive, about 2 miles down the road and back, and the problem didn't occur again. This morning when I started the car it was back to running on one rotor.

When the car is 'running on one rotor' it does not make power, my wideband is reading extremely lean or all over the place, and it does not rev freely.

Is this an issue with my ignition coils? or is this something a lot bigger? any help will be greatly appreciated.

Thanks

 

fuel issue, most likely, sounds kinda like limp mode, but you wil have a cel with that. you didn't say whether it was or was not on. if it's on bet on an OMP problem.

 

no CEL at all. i can hear my fuel pump on however, its a walboro 255lph in tank pump wired to a switch and inline fuse to my battery.

 

if it was limp mode it would idle perfectly fine without any stalling issues.

sounds like a faulty primary injector connection or a loose/corroded ground on the main engine harness to block.

 

Hey Ben, thanks for your input. How can I check for a faulty injector connection? As in, which wire should I check with a multi-meter and what voltage should it be at, or do I have to strip the car down to the injector first?

thanks

 

Light Green/Black wire at pin 3Y should read 12 volts w/key to on. This would tell you that the injector plug is connected solidly to the injector and that both wires are mated well within the plug housing.

 

all 4 injector wires are right in the vicinity where satch mentioned, you may as well check all 4 to see if they are reading 12v key on and close to that while running.

 

all wires checked out. replacing the primaries with new oem ones. However, car has been sitting for quite awhile now because of school and just life in general. Been sitting since august. I want to do the steam cleaning for built up carbon on seals. If I start the car and it is running on one rotor still because of a stuck seal, do I let it warm up to temp on one rotor? Seems kinda sketchy. What is my best alternate option if that is not advised?

 

This is exactly what happened to my s5 before It blew an apex seal sometimes it was on one rotor other times it wasn't I think (not sure) but an apex seal could be getting stuck. I let mine warm up on one rotor (I know I know probably not the best thing) then it would kick back over to both and run perfectly fine. But eventually with it fully warmed up ran it hard and it blew the apex that was sticking. Also this was on a NA.

 

you always have to be careful when issues like this arise, don't push the engine too hard into boost because it's just stressing the rotor that is pulling the engine along and when/if the non firing rotor sees fuel while in boost it creates a lean spike immediately before catching up, which causes detonation.

if the injector clips do not cure it, disconnect the TPS and see if it runs better. a faulty TPS is another possibility for an engine to run on a single rotor if the ECU thinks the engine is decelerating with the throttle closed. it's semi rare but if the TPS registers less than 1.5v and over 1300 RPMs it will go into fuel cut for the rear rotor. if the engine is idling below 1300 RPMs but still only on one rotor then this is much less likely the cause and just a faulty injector/injector clip.

 

Thanks Ben, I got it running. I pulled manifold and saw 12v to both injector clips. Took out the injectors and tested them and cleaned them. Redid the main harness ecu ground, and also found out I don't have a block to chassis ground. Made a new ground and she fired right up. Didn't even need to replace the injectors. Thanks for all the advice guys and sorry about your motor skkitz.