brett0712

Ok... So I just got my car custom tuned down at EPL and it runs strong as hell! But it idles rather odd. So I'll start with here are the codes I am getting:


Address 01: Engine
Control Module Part Number: 8D0 907 551 M
Component and/or Version: 2.7l V6/5VT G 0002
Software Coding: 06611
Work Shop Code: WSC 06325
5 Faults Found:

18058 - Powertrain Data Bus: Missing Message from Instrument Cluster
P1650 - 35-00 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16688 - Cylinder 4: Misfire Detected
P0304 - 35-00 - -
16689 - Cylinder 5: Misfire Detected
P0305 - 35-00 - -
16685 - Cylinder 1: Misfire Detected
P0301 - 35-00 - -

Readiness: 0010 0000

I've already re-coded the cluster so the 18058 code is no more. So here is my issue.

When I start the car up it starts up great but once the idle settles down to about 840-880rpm the misfires start. So I take it for a ride and it drives pretty damn well. Part throttle is pretty good, boost feels good and then I come to a stop and the misfires start. They aren't violent misfires where the whole car shakes but due to my mounts I can feel them. If I hold the idle around 1500rpm it's really rough. Here is the strange part. If you depress the clutch so there is NO load on the engine from the tranny the misfires subside (from what I can tell) and it idles perfect. As soon as you let the clutch out, the idle stumbles and you can then again feel the misfires. I am thinking the idle torque (load at idle) settings are out of whack, but why would that cause the misfires? Why would it ONLY misfire at idle and run fine while in gear and driving. This is why I think the load settings are off...

I flip flopped the ICMs and that changed nothing. I Swapped the coilpacks around and installed all new sparkplugs that came with the EPL fueling kit. I am still getting misfires on the same cylinders!

I was running the APR ko3 93 code before this with a MBC on the KO4s with NO misfires at all. As soon as I installed the hitachi maf, maf housing, injectors, and the new ECU I started getting the misfires. I figured I'd just wait till I went down to EPL to have Tony and Dave check it but the whole time it was on the dyno they had no issues at all.

The whole clutch thing is confusing the crap outta me. When looking at blocks 002, 015, and 016 I notice that while the car is in neutral the engine load is around 16-18% with about 40 misfires per refresh cycle on cylinders 4 and 5. As soon as you depress the clutch, the engine load goes up to about 20-22% and the misfires drop down to about 1-5 per refresh cycles on cylinders 4 and 5.

Like I said... I have pretty much checked everything there is to check for misfires... Plugs, coils, ICMs, some wiring, injectors, pressure test and nothing changed the misfire pattern.

I'm starting to think that the idle part of the tune may be corrupt or something. Is it possible that I have a bad ECU? I bought a stock one and had it flashed with a base map and then drove the car down to EPL. I was getting misfires on the base map as well as after the custom tune was flashed onto it. Is there anyway to test if it is a ~bad ECU. Is it even possible that a ~part of the ECU ram could be bad....

Any help would be MUCH appreciated. I am working with Tony on this to try and figure it out. But seeing he is pretty busy I figured I'd post up here to get some additional help!

Thanks in advanced.


Car info:
2000 S4 6spd
KO4s (all required H/W)
EPL Fueling kit
EPL Custom Tune

Tony@EPL

I will call you in a little while to discuss further.

brett0712

Thanks Tony!!!!!!!

2001s4loored

and increase the idle torque load and up the idle rpms a tad....

brett0712

Or have a really good idea anyway! Thanks though

TheTodd

Please elaborate, since lots of us have similar issues.

brett0712

But it seems as though its bad injector. Im not possitive but ive elminated pretty much everything else.

When i got the injectors from fedex they were just tossed in a box with no padding at all. No caps or anything. So chances are one of them is faulty. Having one bad injector can put the engine out of balance and provoke other misfires.

I will post back after I swap them and see what happens.

TheTodd

before resetting?

On my car they usually get up to around 8 on a cylinder or two before resetting, but at times it gets up to 25. Apparently its never been enough to throw a code, so I'm curious how high it has to be to throw a code.

brett0712

in block 016 cylinder 4 would get up to 25-50 misfires and cyinder 5 would hit about 25 before resetting...

NYImola::NYMisano

Curious cause I had a bad one (and may still have another)