BaOz FD

Hi guys, I have experienced some difficulties with my newly bought PFC. I first installed the PFC on a 93 touring and works great. Two weeks later, I swap the whole engine into a 94 body. I don't think I mess up anything during the installation and basically wires are the same. It starts right up after the installation.

When the engine get totally warm, it revs up and down from around 900 to 1300. It stop after awhile and if I hit the gas pedal, it starts again. It was all working well before the swap. I double check all connections before posting this up. Weird thing is when I put back a stock ECU, it turned out to be very normal. Reading from the PFC commander at idle shows that Inj. Duty bounces around from 0 and 20ish. 0 is where the rpm drops and 20ish is when the rpm raise again. Please help!

Current Mods:
==========
Garrett GT40 Single Turbo Kit
Stock fuel system 550cc/850cc
Stock IC (to limit the PSI because not enough fueling)
DP and MP with stock Catback
Power FC (un-tune)

Things I did trying to solve the problem from search the forum:
============================================
Did the PFC learning procedure
Adjust the idle under the elbow
Connect back the A/C wires
*Nothing works on my case

Thanks inadvance!

cewrx7r1

iTrader: (2)

Do a search about idle problems which is the most common problem for newbs with a PFC.

This has been discussed more times than the SCHIAVO case and it also needs to be put to rest!

Jodeny

iTrader: (3)

You have A LOT of work ahead of you with a stock intercooler/stock injectors and an untuned PFC. How do you expect it not to blow up with a stock PFC map...let alone a stock intercooler which will not limit psi however it will crack open like an egg if you get a bad boost spike..just be very careful and make sure your boost controller works. And get a decent map in there asap. Thats the reason your idle is funky.
John

Matt Hey

Most likely a vacuum leak considering it was working fine before with the same motor. Look a couple of more times. It may just need the idle screw adjusted too. Start with the screw under the elbow. PowerFC needs some time to learn idle also.

Why didn't you upgrade the injectors when the motor was out?

BaOz FD

Problem solved. Thankyou all =)

birdy01

wat was the problem? in case i ever come upon it hehe

i installed my PFC with no problems but jus in case it ever happens to me

BaOz FD

Read the top. It was an idling problem.

1stGenT2

Okay, what was the fix?

fd3s7007

Please share. I'm having similar issues. Morning start idles at 1500-2000 until water temp stabilizers then fluctuates from 900-1300 for bout 30 seconds then normal. I reckon it could be the TPS. Will know this weekend

BaOz FD

What is your idle setting on your PFC?

BaOz FD

I fixed my idle problem by adding a MSD box.

1stGenT2

Thanks for sharing, seriously.

I took my car in to a Mazda dealer to fix a fuel leak and in the process the mechanic found a vacuum leak. He fixed that but the idle now "hunts" over about a 100rpm range and my PowerFC idle adjust setting does nothing except change the displayed number setting (it has no effect on the actual RPM even though the setting is changed).

Thank you again for your information.

BaOz FD

Try to adjust it by using the screw underneath the elbow. There are two more bolts that you can adjust at the throttle body and the throttle cable.

1stGenT2

I did adjust the idle so it's right (~850 rpm) after the engine has warmed up, but on cold start the car stalls because the idle is too low until after warm-up.

Is the PowerFC supposed to control the coldstart idle? The dealer's mechanic might have disconnected the battery to effect the fuel leak repair, which might have reset the PowerFC. so does the PowerFC need to re-learn the idle adjustment?

The mechanic insists that the PowerFC does not control the idle, but ever since he made the repair to correct the fuel leak (caused by a combination of a bad fuel pressure regulator and leaking injector O-rings), the idle hasn't been right and I swear I used to be able to adjust it with the PowerFC.

Where to go from here? Give the PowerFC a few more days to re-learn the proper engine idle RPM under various temperature conditions (assuming the PowerFC controls the idle), run it back to the dealer, or find a local specialist to make it so the first start of the day doesn't stall out?

BaOz FD

What is your PFC idle setting? Do you know how to complete the PFC idle learning procedure? Yes, your PFC can control your idle. Let me know your idle setting.

1stGenT2

PowerFC idle setting had been 900 in all three categories. The dealership adjusted the idle screw -- said it had been backed off nearly all the way, so the mechanic advanced it to about the halfway point of the adjusting screw's length -- it's near 850 rpm. Yesterday I upped the idle settings on the PowerFC to 1200 and left them there just to see if eventually it would have any effect. No change yet.

I don't know if the battery had been disconnected during the fuel leak repair which I understand would reset the PowerFC to its default settings. I do know that I used to be able to adjust the idle speed with the Commander (now it has no effect whatsoever) and the coldstart idle speed is the same as after engine warm-up -- about 850 rpm where he'd manually set it with the idle adjustment screw on the throttle body. That's what really bothers me -- this coldstart idle... When cold, the car starts right up but the idle is too low so it immediately stalls and will continue to do so until the engine has warmed up. The idle on startup used to be around 1500 rpm and would automatically settle to 900 rpm after warm-up. Not anymore...

Even if the PowerFC has been reset to defaults, seems to me that changing the idle settings should have an immediate effect, which it did in the past -- before this guy tore everything apart to fix the leak. I mean like does the ECU need to relearn its settings before they can be adjusted using the Commander?

BaOz FD

The PFC will not reset due to battery remove. My PFC can only go up to 1100 for A/C setting and 900 on normal. You do not need to relearn if you have a commander. You can manually change the idle settings. I drive a 3 gen with a single setup. Idle is a bitch at the beginning, but after all the work, it's now great and staple as a rock. If you have a stock engine with very few mods, you should load your base map in. What's the history of your PFC? If it's used, maybe the previous owner had a different setting than yours. -Rick