Quote:
Originally Posted by PTAddict
BTW, lest it seem I'm just picking on FAST, we've recently had two potential customers drop in with the same kind of issues using the MSD "Atomic" system. We've told them we can try to help within the parameters provided by the hand held tuner, but there are no guarantees or even high confidence we'll fix their problems. So far, no takers on that bet ... Maybe I just live in some kind of vortex that attracts these problems  |
I'd suggest that troubleshooting begins with a complete review of the install before you ever pick up the handheld.
The definition of insanity is to do the same thing over and over again and expect a different result. That is usually what happens with the handheld settings -- they're run over and over with minor tweaks --- resulting is a POS running car because it didn't fix the issue.
Finding the fault should simply begin with the fuel system - since that's all the ECU controls.... Are they running old crappy fuel lines that the new fuels have disintegrated and they're now causing issues with the filters or injectors.... Are there pre and aft filters of the proper size surrounding the fuel pump.... is the pressure set correctly in the ECU and actual readings... Next I look at the O2 sensor. It's usually fouled beyond recognition. I won't tell you how to clean it... I assume you know how. If not - just replace it.
Then I go for the wiring -- and that's where 90% of the issues are. Bad connections - connectors poorly crimped - bad or missing grounds - wiring intermingled with the MSD box or ECU too close to the MSD box.... Then I jump to the distributor curve and timing... checking the MAP sensor and it's install and source... and then finally pull the plugs because they'll be a disaster.... because usually the issues are from TOO MUCH fuel once the car runs like crap and the system can't adjust.
I don't bother to even turn the car over until I've checked every single facet of the install -- to include any sensor install (like tape used to seal the threads). The system won't start to self tune until it hits 140*.
Clear out the "program" and start over... making certain to know what injectors are being used. I like to default to putting in the injector sizing etc rather than selecting one of the "known" kit numbers.
On IR systems it takes a bit more prep -- and something that many don't do is they don't disconnect the linkage before making adjustments. They are IR systems for a reason! There's this word in there --- INDIVIDUAL..... side to side linkage has to be disconnected... and a manometer used to adjust each intake until they're perfect. If one is missed up the entire thing is messed up.
Sometimes the actual physical butterfly(s) needs to be tweaked.
And then the linkage is hooked back up once the idle and everything else is running as it should... and if hooking that up changes anything - then the linkage needs to be adjusted.
Finally I go back in to the handheld and reset the throttle for idle and WOT.... and fire it back off and adjust the idle in the handheld to where the car is currently idling. I never use a IAC in these systems - it's not necessary. But I like to set the physical idle - get the timing all dialed in etc -- and then go back and tell the ECU what the idle RPM is. It, of course, can't adjust the idle which is why it's asking for that info (it wants to control the IAC)... so I want the ECU to just see the tach input is say 800 --- and I know the motor is idling at 800 so I tell the handheld that the idle is set to 800. DONE.
I just did a Brodix headed 496 BBC --- IR --- It's idle doesn't vary 25 rpms using my dial back timing light that has RPM capability. That's confirmed by the handheld info screen as well.
Brian Hobaugh SCCA National Tour June 2014
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