Snowblind113

Hey guys,

This is my first time using the Power FC on my car, before I plugged it in I rebuilt my entire motor and removed the OMP. I've run the idle learn procedure and have a smooth idle at ~750rpm.

Now the problems,

Difficulty starting after it has warmed up
Acceleration is lagging
When put in gear and gas pedal pressed it will struggle to start moving.

The car is 100% stock other than the omp removal and I am running 1oz per gallon of premix.

Sorry to flood the board with more question threads, but I appreciate any feedback on these issues.

-Pete

blmcquig

iTrader: (15)

do you have a wideband?

Snowblind113

Nope.

Mods:

OMP removal (was convinced after tearing down my motor)
Power FC w/ Commander

Model:

1994 RX-7

Snowblind113

I thought I should add that after going through my IGL map it has a lot of zeros, especially under the n01-no3 column

cewrx7r1

iTrader: (2)

No stock or base mod map has 0 IGL around the idle area.
Now give us the history of the PFC and who touched it?
Have you re-initialized the PFC which should help?

arghx

iTrader: (3)

Go to the water temp screen, press the Next button, and you should have your cranking fuel there. You can remove fuel at the higher water temperatures to possibly help with hot starts. Otherwise your motor may just be building compression still.

If it were me, I would put the stock ECU back in and plug in the OMP (leave it dangling somewhere) until the engine is broken in.

Snowblind113

You're correct, the values i thought were zero were actually set at 8. The screen wasn't illuminated well enough. A gentleman on the forums owned the pfc before me and it was set up for a single turbo, I have reset the Power FC and done the Idle Learn procedure.

I have blocked off the vacuum tubes from the rats nest going into the omp "injectors", will this throw a trouble code on the stock ecu? And what about the 4 wires that I removed for the power fc?

blue87

iTrader: (2)

Correct me if I am wrong guys, but I don't think the vac lines will cause a trouble code. just like ARGHX said electrically connect the OMP... Can you temporarily reconnect the other 4 wires.

I would also connect teh stock ECU since the vehicle is stock during the break-in period. If nothing else it will allow you to troubleshoot the rebuild. If it runs fine with the stock ECU then you can tune the PFC. if you are having other problems, vac leaks, building compression etc you might keep going in circles with the tuning...

Bascially just trying to change as little as possible in each step... easier to troubleshoot.

blue87

iTrader: (2)

Oh, and I would strongly recommend getting a wideband if you plan on tuning your car, if you are going to have someone else do it maybe not necessary... but it would be my first "mod" otherwise it is really hard to tell what is going on, as many driveability syptoms could be too rich or too lean and hard to tell the diff...

arghx

iTrader: (3)

the wires you cut are for accelerated warmup system and EGR. they might throw a code on the stock ECU (I've never tried) but I wouldn't worry about it, as long as you don't go into limp mode.

I agree with blue87. you have the luxury of doing this incrementally so you might as well take advantage of it

Snowblind113

I reconnected the stock ECU (without the 4 wires reconnected) and here are the results thus far in the form of youtube videos:

http://www.youtube.com/watch?v=sQUv5tJBXaY - Shaky Idle and lagging throttle response time.

http://www.youtube.com/watch?v=QrPkYdrFyjo - At full temp, starts up fine when cool or warming up.

These might not be real issues at all, but this is my first rotary rebuild and Im being as cautious as possible. Thanks for all the help thus far, I really appreciate it.

blmcquig

iTrader: (15)

kinda sounds too rich? like its flooded maybe...
did you try holding the pedal to the floor? (usually that cuts fuel off when cranking, on the stock ecu)
i have no idea really, the sound on the video is quiet.
idk, just a thought.

arghx

iTrader: (3)

On the subject of the rough idle: is the engine ported? On the stock ECU did you perform the idle speed adjustment procedure in the factory service manual? I don't understand what you mean by throttle response problems, based on the first vid. Could you clarify? And have you checked to make sure your TPS voltages are in spec? You can plug the PFC in real quick and they will be listed under etc --> sensor/sw check. Full range is VTA1 and narrow range is VTA2.

The hot start problem can occur on rebuilt engines that have not broken in, especially when you reuse a lot of stuff. If you have loose clearances or worn housings it can take a while for the engine to build enough compression for a good hot start. If you do decide to put the Power FC back in you can try reducing the cranking fuel during a hot start. This is under the water temperature screen in the Commander.

Snowblind113

Ill check the TPS voltages in the morning and run the idle speed adjustment procedure. but in the first video I was hitting the gas to rev it to 3k and it couldn't make it without me pushing even harder on the peddle to get it there, it was making slight popping noises as if the timing was off (this happened with the PFC as well but only when the car was in gear and I tried to drive, but it didnt stall like this or have throttle problems when idle)

Snowblind113

plugged the stock ecu in and it won't even start now. i then took it out, reinstalled the power fc and it also wouldnt let it start.. but now something weird is happening, after trying to start and leaving the key on im getting a buzzing noise near the rats nest, it goes away when the key is shut off, must be a solenoid.

also i checked the tps voltages, they are as follows:
vta 1: .48v
vta 2: 1.10v

Ive included a photo of the sensor check screen, i apologize for the blurriness.

and here is a video of the most likely bum solenoid:

http://www.youtube.com/watch?v=5V-ZQAMjGfg

oh and the engine is not ported..

again thank you for helping me troubleshoot this online.

cewrx7r1

iTrader: (2)

If the engine has the original engine wiring harness, then most likely that is the problem. Because once you remove and re-install it, it is hosed. This problem was notice with original harnesses only about 5 years old here in the south. Heat destroys them.

Any FD that is being rebuilt and has the stock engine harness, MUST include a new harness. A few of us have learned the hard way when rebuilding engines and now we make it a REQUIREMENT for our customers.

My new 1999 harness (11 years old now) is in better condition that my original was when replace at age 7 years. Better quality wiring!