Hi, all

Today I picked my car after 1 week settling and car wasn't runing good at all... car is losing power under soft load... even with 15% of accel.... it feels like... flooding...

1st. i was on a circle.. shifted to 2nd gear and while pressing accel car flooded at 3k rpm.. and was backfiring hard.... constantly.. like a fuel cut.. on piston cars... i lifted foot instantly...

after that was trying to drive always with soft load and cars runs normal with low load 10% accel or less...

2nd. cruising on highway... runs normal but when reaching the 3k rpm... again floods...

3rd. exiting a circle on 2nd gear at 1.5k rpm... needed to put some load on accel and again!!! flooded....

I've made a short video returning to home check carefully secs 0:06 you will note...

http://www.youtube.com/watch?v=PRnbucb5xYg

Please help me I'm very worried... I don't know what could be the problem, car was perfect last week.. I've no check engine light or something

P.S. boost reads are moving differently... today driving slowly.. on 3rd gear 2k rpm... light load... boost gauge was showing a read from vacuum closer to 0 psi...

and before this problem normally i only got reads above 0 psi with some load on accel... never like this...

 

sound like either you're in limp mode or your coils are firing correctly. I will try to pull codes to see if there is any.

If not, please make sure your car is not lowered enough to rub the passenger front wheel-well harness which can cause this problem.

How's the idle? Also, check your MAP sensor to make sure everything is plugged in.

Report back after you've checked these.

-AzEKnightz

 

Check hoses for MAP sensor.

 

You might want to read the Mazda technical bulletin attached in post #42 of this thread.

 

Great info, but I think this is mislead due to the fact that he's having backfire and the car doesnt pass 3000 rpm. It's different from what was describe on the thread you posted.

-AzEKnightz

 

Updates

Today I've tried to get the codes followiing webinstructions about bridging gnd and ten on diagnosis conector...

but when I've tried i found that my car was dead!!! when moving the key to "ON" position only the light of "recirculation" on dash was turning on... nothing else...

so i went to engine bay to check battery... after a small hit on battery positive contact car was back to life...



I don't know if all my problem could be a false contact between that small black box next to postive contact... just in case here is picture of the mentioned box..

so decided to get the codes



nothing!!!



So, I was thinking maybe ECU got reseted when car was dead.. so decided to took car for a ride... and still the same... floods... but i used that failed ride to make a video to show you the weird boost pattern... even with light throttle... boost needle is moving closer to 0 PSI

http://www.youtube.com/watch?v=F1fJ-jJ5pzI

and also 1 video of car idling

http://www.youtube.com/watch?v=uzd5p8B5JK0


so came back to home to check why i didnt get any code.... and i found that JDM cars doesn't have the check engine cell light in dash.... "more problems" for me...

so tomorrow im gonna with a friend and he has a bulb tester... (that one to find voltage sources when installing gauges, etc) or gonna try with a multimeter...

Also I've checked wheels.. if there is some cables getting touched by wheels... but nothing... Everything clear...

Im desesperated.. I'm really worried... gonna try changing spark plugs tomorrow...

does someone experienced the same? should i check something else?

thanks for helping....

 

First of all, let's try resetting the ECU's memory by disconnect both battery terminal and connect them together for 10-15 seconds. Re-Attach the terminals and then try to retrieve code.

I dont know about "No check engine cell" for JDM cluster true or not. Otherwise it'll be difficult to diagnose if there's no check engine light.

Did you check your MAP sensor hose to make sure it is attached?

Very interesting as I've not work on a JDM FD before, would love to help you out but you are too far away for me to diagnose this problem. I will try my best through the internet though =).

-EZ

 

Sounds like fuel system is screw (injectors to be exact) I remember having an issues like that back in 96, the rear secondary injectors was stuck open. According your rps cut off power tha's when the secondary kicks in. Again you may get right fuel pressure but how well does the injectors spray under load? Only way to tell is send them out for cleaning.
Khris

 

More updates, I've tried to get the codes following this post https://www.rx7club.com/3rd-gen-archives-73/there-any-chance-read-ecu-codes-without-ecl-238994/ without sucess...

Also warmed up the car and it can rev more than 3k rpm in neutral...

but still the same coming back to home... car bucks under light load... can't press the accel too fast.. and boost needle is moving closer to 0 psi at low rpms... in 1st gear 2nd gear if i go slowly pressing the accel i can pass the 3k rpm but no in higher gears...

I'm very lost... when it happens.. it feels... like a spark cut...

I don't know if its maybe turbo actuators working badly...

please help me... im start hating rotaries... can't bring the car to any normal workshop to get help... and just a few info...

 

The electrics running an RX-7 engine (like a lot of others) are very sensitive to ground connection cleanliness and tightness. I would do "management by walking around" first, i.e. make sure all the electrical grounds, including those in my link above, are in fact in good shape. Maybe that's not the problem... indeed it could be fuel injectors... but they certainly could be the source of your misery.

 

Have you checked this one allready? As two people have suggested this one. The MAP sensor is in the fire wall at the passanger side as you have JDM, black littlebox one vacuum hose goes to UIM from it, check both ends.

 

More updates

Spark plugs changed, Grounds, checked and cleaned, Map sensor hose checked (both sides) and nothing... problem stills...

boost stills building at low rpms, and car floods under load... and boost needle is doing crazy things...

pictures of my spark plugs

they're bur7eq (leading)




bur9eq (trailing)




can this be a problem with turbo valves? or a boost leak?

 

bump for help!

 

More updates... went to mazda official service to get "check engine codes" and nothing...

they've mentioned that maybe is a cloged fuel filter the problem...

 

Bump! after hours searching can't find anything related... please help im pretty sure there is a lot of people who had experienced something like this...

 

Did you've checked your TPS?

Had similar problems on my old fc3s, this was the solution...

 

Bad spark plug wires and /or coils could cause this. I had a similar problem years ago and it was a bad plug wire.

Anything bad in the ignition system will have similar results.

Also, since it seems as though the connections to the battery may be questionable, based on one of your comments, make sure you clean those and make sure they contact with almost zero resistance. As someone said earlier, bad grounds will cause many problems.

 

Try adding some high octane fuel on it.

 

uh, in your picture you bridged the B+ post and not the "ten" terminal which should blow out the computer fuse in the cabin(or the ignition fuse, i've never messed with that B+ diagnostic circuit before). assuming you replaced that to get the car running again, for getting codes, pin "ten" is right next to the terminal you need to ground. i also ground pin "ten" to the battery negative instead to avoid any possible wiring issues or faulty ground circuit to the diagnostic box.

usually your issue is attributed to the Y pipe rubber coupler cracking and/or blowing out, losing boost. or the wiring under the left front fender getting munched from wider wheels on lowered suspension, turn the wheel and inspect the fender splash guard to see if the wheel is rubbing through into the harness.

a pressure tester for the twins system isn't too difficult to make with plumbing couplers from any hardware store, pressurizing the system and looking for leaks with a spray bottle with soapy water and your ears listening for hissing sounds.

all else fails, get a wideband to see if it is rich or lean and start testing fuel pressure and injectors.

that is if no codes are present when checking properly(at least that picture REALLY looks like the wrong spot, could be camera angle).

 

thanks for repply today I bought a multimeter decided to check my TPS, but firstly I've tried to get "again" ecu error codes following instructions

and got it! I'm not expericienced reading this things so just to be totally sure I've made a video with the flashes

http://youtu.be/YdtSgvJgg70

If i'm not wrong I've codes " 13 " and "45"

13 Pressure Sensor (Intake Manifold Pressure) <= where is that sensor?

45 Solenoid Valve (Charge Control) <= any procedure to diagnose or maybe the pressure sensor is affecting this valve?

or any procedure to diagnose them? maybe unplugging etc..?

and the most important those 2 things can be the reason of my problem?

 

if you're getting a map sensor code do the check of the left front harness i described earlier, that is usually the cause for that code.


usually your issue is attributed to the Y pipe rubber coupler cracking and/or blowing out, losing boost. or the wiring under the left front fender getting munched from wider wheels on lowered suspension, turn the wheel and inspect the fender splash guard to see if the wheel is rubbing through into the harness.

 

More updates

yesterday I've checked the fender splash turning the wheel, and nothing everything was clean







After that I've decided to check the famous rubber joint of the Y Pipe and i found everything in good condition... rubber joint is pretty thick and looked in good condition no fissures or dried out... also I've checked my crossover pipe and looked in pretty good shape... strong... I don't know how it breaks... its a thick tube.... i was expecting a thin tube prone to crack...

but i found that my crossover pipe (on the side that connects to Y Pipe) was a bit oily and also that Y pipe joint was oily and looking inside of the Y-Pipe it looked oily too check below pictures...

















So, after inspecting... I've decided to clean with a rag a bit carefully and reassembled everything adjusting everything properly... in regard to avoid any possible leak

I've decided to reset the ecu... ground unplugged for 30 secs brake pedal pressed and went for a ride to test car... and after that check for any error code

and voila! car was able to pass the 3000 rpms... is not bucking under load... boost looks normal now.... so, returned to home and went to check error codes...

and now im getting "error code 6"

http://youtu.be/g2Cd4D9F-O0

I've made a video with the new code... just in case im reading the codes on the wrong way...

why I'm getting this code now? speedometer is moving properly no issues at all...

 

Here is the Code 6 troubleshooting procedure from the 1994 FWM. (Click the picture twice to enlarge it.)

 

Arthas,

Any updates? Is your car back to normal still? I am having the same issues you were. I haven't pulled any codes yet but it has been having the same hesitation/bogging/feeling of fuel cut past 3000rpm. I am going to check my y-pipe, crossover tube, and coupling/rubber joint as I know it's caked in oil. Then I'm going to reset the ECU as well. Hopefully this takes care of my issue, too.

 

why not check ur codes before you reset your ecu and checking the rest of the list? Start with the basic, you dont wanna reset the ecu and "hope" for the car to cure itself.

-AzEKnightz