Is there any where (hopefully in the US) that I can send my PFC to be tested/repaired?

I’m having a tuning issue that I can not for the life of me track down.


In a condensed nut shell, I am having a part throttle LEAN spike. So lean in fact my LM-1 cant even read it. Right before the secondary throttle plates open. Its not boost dependent but it is very position dependant. Whether it’s in vacuum or boost doesn’t matter. Its also not temperature dependant.

Of course logic would dictate it’s a TPS sensor problem. Unfortunately its not. As I have checked the sweep (both High and Low over and over) I even replaced it with a new one. I assume there isn’t a problem with the harness since the PFC reads through the harness(checked the sweep throught the commander). My next thought was a problem with the map sensor. Checked and replaced also to no avail.


To make a long story short: One day wile racking my brain and cussing profusely. I noticed some thing kind of odd in my data logit log . Wile I was logging IDC’s I did not see any spike when I blipped the throttle. So I decided to see if some thing is wrong so I set acceleration MS setting to ungodly values and still I don’t see any spike in IDC’s. So I’m thinking I have a problem in my PFC/Commander.

If I have a problem with my PFC it would explain my issue along with some other goofy things is does every now and again.


So the question stands, Any one know if I can get it repaired? (Apexi has been LESS than helpful in regards to this)

 

About leaness just before/around secondary throttle plates opening:
I have posted about this before. In a nut shell: the secondary plates open and air flows through the secondary ports and mixes with the air from the primary ports.
But there is no fuel being injected into the secondary ports air flow. This initally causes poor mixing and misfire. This is only noticeable at cruise or very slow throttle opening. Those fuel cells need to be richer. The seondary injectors also come on line too too late. The PFC when set up show 40% but is actually about 47% IDC. Better to set this to 30% on settings 5.

As for your IDC not increasing when blipping, instead of only trying ACCEL richness, also try FUEL CELL richness. The blip may be to short for the DL to see. If the DL HOLD OFF value is set higher than the injector change time, it will not be shown! For logging, a hold off of 20ms is normal.
That means any data not within the cells for at lease 20ms is removed.
Have you ever looked at at a log and notice how this affects data and data count?

 

Hey Chuck,



My lean spike isn’t related to any cell, its not load or rpm dependant. Its only throttle position dependant, (only wile moving. if I keep the throttle steady even at that point the AFR’s stabilize. Its only when I am depressing the throttle and go past that point that I get the lean spike) And my PRI/SEC transition is at 30%, and my sec transition MS is at .7……something (can’t remember the exact number off hand) with my 1600 sec injectors. (3 ohm resisters)


When I was logging to look for IDC spikes I only logged IDC (to speed up the capture rate) and I set the “hold off” to 0, and ran the test over and over. Now I could be wrong, but I would have expected to see an IDC spike at some time, even with a slow capture rate. Even if it was just dumb luck to capture that specific moment.


However, wile reading another post here I realized that I reset my TPS wrong. I set it with the idle stop set to keep my large street port running (I use manual control over my idle). It just slipped my mind to wind the throttle stop back down to stock. I’m going to sort that out real quick but I don’t have any real hopes that that will sort it out. But its Sunday and its nice out, so I might as well do some thing out side

 

My car is set to factory specs for TPS voltages but my engine idles around 1000 rpm. Thus my idle TPS voltages are higher than stock. This is what you would see if you reved a stock engine to 1000 rpm.

ZIP and mail me your map to cewrx7r1@yahoo.com and I will give it a quick critique. List all engine mods, and boost your run.

 

Ok will do.


I also logged a few runs today so I’ll toss them in there as well. From reviewing the logs from today I think I know what’s up with it. But I’ll reserve judgment till I get a chance to chat with ya. No sense in spending the coin to send it in, if it turns out I missed some thing in the data.


Thanks a bunch for taking a look at it.

 

BTW reseting my TPS improved throtle responce but didnt efect my lean spike problem.