bdender

I'll list out what happened, cause some or much of it will likely be relevant.

- Recently installed a power FC on my 94 rx7
- Experienced idle hunting when car was hot
- took off throttle body elbow to adjust throttle screw
- closed screw and turned half turn out
- drove for a while
- idle hunting issue persisted at hot temps
- went to adjust throttle screw to a more closed position
- found that one of the top bolts had ripped in half and end screw was gone
- adjusted throttle screw as noted to a more closed position
- reinstalled throttle body elbow with only one top screw in place
- heard a loud gunshot volume pop when starting the car
- tiny amount of oil on top of throttle body found
- have adjusted throttle screw several times - very rough idle start each time i start car now
- white smoke from exhaust accompanies the rough idle

Wishing now I hadn't messed with it... the loud pop scares me dearly... thoughts? suggestions?

MR_Rick

iTrader: (7)

Did you fallow the idle learning procedures?

If you haven't done this, I would start here.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/how-make-your-untuned-pfc-basemap-safer-idle-better-no-datalogit-needed-841706/

bdender

I'd done all that except turning the o2 sensor off for the learning procedure. Problem is that the car used to idle fine for the learning procedure, now it just surges big time from ignition even after clearing the PFC to learn all over again.

I still need to get the top two bolts from the throttle body elbow out and replace them. The thread ripped in half due to being overtightened. Maybe since i can't bolt those top two screws on outside air is getting into the throttle body?

I really can't figure this out.

bdender

Also of note, white smoke pours from exhaust when I idle now. This is definitely new. Smells a little sweet, which makes me think coolant.

bdender

bump

bdender

Been a very frustrating past two days... let me list out what has happened, as it may help diagnosing the issue. I really need your guys' suggestions/help.

I'll list out what happened, cause some or much of it will likely be relevant.

- Recently installed a power FC on my 94 rx7
- Experienced idle hunting when car was hot
- took off throttle body elbow to adjust throttle screw
- closed screw and turned half turn out
- drove for a while
- idle hunting issue persisted at hot temps
- went to adjust throttle screw to a more closed position
- found that one of the top bolts had ripped in half and end nut was gone
- adjusted throttle screw as noted to a more closed position
- reinstalled throttle body elbow with only one top screw in place
- heard a loud gunshot volume pop when starting the car
- tiny amount of oil on top of throttle body found
- have adjusted throttle screw several times - very rough idle start each time i start car now
- white smoke from exhaust accompanies the rough idle
- used pliers to remove top bolts from throttle body elbow and replaced with same size bolt
- noticed that after some idle smoke was turning grey, and that boost was registering at -40 on power fc
- vacuum to map sensor had come loose - plugged that bad boy back in
- no more smoke from exhaust and boost is back
- car still idles rough though, and car is shaking a little at idle
- loud pop from exhaust is heard and it's accompanied by a static noise from or in very close proximity to throttle body

Any idea what that could be? Any help/suggestions are very much needed right now

bdender

Also something that may be of note - idle speed right now when attempting to do the learn idle with power FC sits over 900rpm with A/C and everything shut off. Higher than it should be.

bdender

Also, static noise persists when car is not running

KKMpunkrock2011

iTrader: (5)

static noise is usually a wiring problem, bad ground or a blown relay, wiring might also be the cause of shitty idle.

Lemme know what you find, mine behaved similarly before I blew the motor.

bdender

Last thing anyone wants is a blown motor. Based on what you're saying, sounds like it's time for me to tow it into a professional. That sound about right?

KKMpunkrock2011

iTrader: (5)

I'm not sure whether the idle problems were a precursor to a blown motor or not. There are two facts in that statement.
1)I had idle problems.
2)A few months after they developed, I blew the motor.

Whether 1 led to 2 or not I do not know. Check compression, and pressure check the coolant system if the smoke is white and sweet smelling. Pray for the best but plan for the worst.

bdender

I'm fortunate that i found the cause of the smoke. Vacuum to the map sensor had come loose. What i have left now is rough idle and static noise from throttle body. Think i'll have a professional check on all the wiring and hoses. While they're at it, also replace remaining hoses that aren't silicone yet.

I'm just actively avoiding the thought of what it'll cost me for now... Bad time financially. I can only hope that'll fix things up.

rfox

BDENDER:
I am having identical things happen to my car.

Here's what happened to me. Parked car for winter, took car out. Coolant leak. Turns out mice ate through many of the hoses in the car. Fixed hoses, car ran good but I noticed smoke under full throttle.

Fast forward - mice got into engine bay again and this time ate the coolant overflow cap. I took the car out, not realizing it and the car overheated. I stopped and shut the car off. Then 20 minutes later got water into it, and drove home. As I approached my house the temp surged again so I coasted home and shut it off. Then I bought a new cap and installed it. I also flushed the coolant and put fresh coolant in.

Started car and it now has horrible idle and absolutely pours white smoke.

But I know everything got really hot when it overheated so is it possible a hose popped off?

I want to know what your final outcome was.

KKMpunkrock2011

iTrader: (5)

overheating and smoking like a sonofabitch means it's time for a rebuild, your coolant seals are done for.

bdender

Hey all,

Since getting a Power FC in my FD, I've been experiencing some idle hunting issues. I've found that it only kicks in when water temps are at or above 103 degrees Celsius. Once temperature drops below that it goes away.

Any ideas? Likely a non issue once I get the new intercooler in there, but I was hoping someone might be able to shed some light on the issue.

bdender

Quite honestly I don't understand why that thread was merged with this one. Many of the issues described here were unrelated and resolved.

Since I have no choice, I'll update here. The FPR solenoid had gone bad, and the air control valve needed to be cleaned out. I did a few other things as well while I was at it... replaced vacuum hoses for hose tech silicone hoses, replaced the stock FPR for an aeromotive FPR, and removed excess solenoids (simplified sequential).

Ran the learning sequence for the Power FC, and adjusted idle a little till it was feeling right. However, one issue remains as explained in the post that was moved here. Any thoughts?