another weird issue

Kenny Senter · 01-09-2009, 12:25 AM

so occasionally (happening more often now) the car will just die. This used to happen while decelerating but is now happening while just cruising, normal cruising. The car will just DIE. It falls flat on its face and dies, no hesitations, no stutters, nothing, just dead and it decelerates slowly like I let off the gas with no drag other than normal. It takes me a while to get it restarted by flipping the fuel pump switch off and on forever until it starts coughing then finally starts.

Problem is, I dunno WTF to think of it. It isnt running out of fuel, because it does sputter and spit til its dead, it just dies. It almost makes me think its flooding under normal driving conditions. I dunno if its an AFC problem, an injector problem, ECU problem, etc. Hell, it could be ignition for all I know. The only thing that makes me think its not ignition is when it finally does start back up, it coughs and hesitates for a few then finally fires. Almost like its clearing out from a flooded condition.

trying to find someone local with a wideband I can borrow to help diagnose if its a fuel issue or not.

Voltage is fine (around 13-14 volts it seems from stock instrum. cluster, most the time), water temps are fine (180-190*F), fuel level is half tank.

I am stumped.

please, any info is appreciated.

NoDOHC · 01-09-2009, 11:43 PM

This could be about anything... Leaking injector, bad Fuel pressure regulator, intermittent short on injector wire, bad spark plugs/wires, plugged fuel return line, Stick AFM, bad MAP sensor, and the list goes on.

I think that the wideband is a good troubleshooting option (they only cost about $200.00)

You could also install a fuel pressure regulator and visually inspect the wiring.

Polito Racing · 01-10-2009, 05:20 PM

have you checked compression on the engine?

vex · 01-10-2009, 07:39 PM

Quote:

Originally Posted by Polito Racing

have you checked compression on the engine?

I second this question. There's just not enough known about your engine. Lets see what the condition of the seals are in.

Kenny Senter · 01-11-2009, 01:03 PM

well, it is very intermittent so I dont suspect the engine all too quick. It was rebuilt about 20k miles ago by a very knowledgable rotary guy. Not boosted so the likelyhood is low, but I guess you can never rule that out.

The injectors were sent off and thoroughly cleaned, inspected, flowed, etc on the rebuild, but once again, they could always fail.

Not ruling anything out as of the moment but having problems diagnosing the problem, argh.

one320fc · 01-11-2009, 02:11 PM

I would recommend checking all the basics if you havnt done so already get a timing light and make sure your ignition if firing leading and trailing. If you know some one who has a efi fuel pressure gauge check the fuel pressure. Also a lil more info on your car could help others give you some ideas I assume its a 13B turbo and you have supporting mods if your running a AFC

RoughRex · 01-11-2009, 03:40 PM

haha, this was happening to my car too. It was so infrequent I never bothered to look into it (too many bigger issues). Anyway, I just found something interesting over thanksgiving.. I took my dad for a ride in the car and I didn't make it 2 blocks before it started dying, every time I hit the brakes the car died. I was pretty stumped because I had just driven the car all the way home from work (about an hour) with no issue. The next day something occurred to me.. I had a passenger EVERY time the car died at "random". So I started the car up in the driveway and let it get to normal temp, then I hit the brakes and tested, nothing. I put it in neutral, got out and went to the passenger side. I then proceeded to gently push the carpet down with my foot around the ECU area until BINGO!! the car started to sputter and die.

I haven't actually "fixed" the problem yet but I did move the wiring harness so that you can push on it and it has no effect.

Anyway, sorry for making it story time. But that's what was causing this problem in my car.

Phoenix7 · 01-11-2009, 04:13 PM

That's a good one. Sometimes people forget there is no brake on that side.

gotta start knocking things out in order...you're already on the right track...good luck. Have you checked the intake pipe for cracks/vac leaks?

Kenny Senter · 01-12-2009, 04:03 PM

havent really done much at all in way of checking things, as crappy as that sounds. There is just so many different things it could be.

The air intake tube is fine. Doesnt look to be any fuel leaks.

I swear its acting like a fuel issue, like its flooding or something. I was gonna get online and order some parts from mazdatrix and just start throwing parts at it, but then I got to the prices...HOLY HELL! Anyway, if it dies I can turn the key over and about 8-10 seconds into cranking it will start to sputter to life but if I even think about touching the accel. pedal it totally kills any progress, lol. Switching the fuel pump off does seem to help slightly but of course doesnt crank and same symptoms when pump is switched back on. Once it finally does crank, it runs like a damn champ...until next time of course.

Any other options for a fuel pump, FPR, Air Bypass Valve (idle surge every now and then, but small 830-550ish), Airflow Meter (FRIGGIN $900!!!, screw that!), etc etc?

unfortunately, not tail light related, lol.

I am gonna check all the connections on the SAFC again, but I really dont suspect it, but never know at this point. Just want my damn car to run reliably again, hahaha, rx7 = reliable?

Phoenix7 · 01-12-2009, 09:48 PM

checked your SAFC and TPS?

I'm rolling on 217K miles and all I've done was maintenance, preventative repairs and fuel. The unreliability rep comes from the owners....

So, can you get a video posted? Hot start issues? Is it a stock pump? has it been modified in the past?

I wanted to say injectors but they've been cleaned already....

Now even tapping the gas (barely raising the RPMs) kills it?

01-09-2009, 12:25 AM	#1
Kenny Senter The Newbie Join Date: Sep 2008 iTrader: (0) Posts: 27 Rep Power: 0	another weird issue so occasionally (happening more often now) the car will just die. This used to happen while decelerating but is now happening while just cruising, normal cruising. The car will just DIE. It falls flat on its face and dies, no hesitations, no stutters, nothing, just dead and it decelerates slowly like I let off the gas with no drag other than normal. It takes me a while to get it restarted by flipping the fuel pump switch off and on forever until it starts coughing then finally starts. Problem is, I dunno WTF to think of it. It isnt running out of fuel, because it does sputter and spit til its dead, it just dies. It almost makes me think its flooding under normal driving conditions. I dunno if its an AFC problem, an injector problem, ECU problem, etc. Hell, it could be ignition for all I know. The only thing that makes me think its not ignition is when it finally does start back up, it coughs and hesitates for a few then finally fires. Almost like its clearing out from a flooded condition. trying to find someone local with a wideband I can borrow to help diagnose if its a fuel issue or not. Voltage is fine (around 13-14 volts it seems from stock instrum. cluster, most the time), water temps are fine (180-190*F), fuel level is half tank. I am stumped. please, any info is appreciated.

01-09-2009, 11:43 PM	#2
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin iTrader: (1) Posts: 855 Rep Power: 17	This could be about anything... Leaking injector, bad Fuel pressure regulator, intermittent short on injector wire, bad spark plugs/wires, plugged fuel return line, Stick AFM, bad MAP sensor, and the list goes on. I think that the wideband is a good troubleshooting option (they only cost about $200.00) You could also install a fuel pressure regulator and visually inspect the wiring. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)

01-10-2009, 05:20 PM	#3
Polito Racing so you got pistons oh wow Join Date: Mar 2008 Location: Raeford NC iTrader: (0) Posts: 87 Rep Power: 17	have you checked compression on the engine? __________________ Polito Racing 2000 F-350 SD (Daily Driver) 2002 CBR 954RR (Back on the Road) 1987 RX-7 Turbo II(red bullet!!)

01-11-2009, 03:40 PM	#7
RoughRex Out of Nickels and Dimes Join Date: Mar 2008 Location: Nashville, TN iTrader: (0) Posts: 192 Rep Power: 17	haha, this was happening to my car too. It was so infrequent I never bothered to look into it (too many bigger issues). Anyway, I just found something interesting over thanksgiving.. I took my dad for a ride in the car and I didn't make it 2 blocks before it started dying, every time I hit the brakes the car died. I was pretty stumped because I had just driven the car all the way home from work (about an hour) with no issue. The next day something occurred to me.. I had a passenger EVERY time the car died at "random". So I started the car up in the driveway and let it get to normal temp, then I hit the brakes and tested, nothing. I put it in neutral, got out and went to the passenger side. I then proceeded to gently push the carpet down with my foot around the ECU area until BINGO!! the car started to sputter and die. I haven't actually "fixed" the problem yet but I did move the wiring harness so that you can push on it and it has no effect. Anyway, sorry for making it story time. But that's what was causing this problem in my car. __________________ 1988 GXL

01-11-2009, 01:03 PM	#5
Kenny Senter The Newbie Join Date: Sep 2008 iTrader: (0) Posts: 27 Rep Power: 0	well, it is very intermittent so I dont suspect the engine all too quick. It was rebuilt about 20k miles ago by a very knowledgable rotary guy. Not boosted so the likelyhood is low, but I guess you can never rule that out. The injectors were sent off and thoroughly cleaned, inspected, flowed, etc on the rebuild, but once again, they could always fail. Not ruling anything out as of the moment but having problems diagnosing the problem, argh.

01-11-2009, 02:11 PM	#6
one320fc one Apex @ a time Join Date: Feb 2008 Location: Culpeper VA iTrader: (1) Posts: 272 Rep Power: 17	I would recommend checking all the basics if you havnt done so already get a timing light and make sure your ignition if firing leading and trailing. If you know some one who has a efi fuel pressure gauge check the fuel pressure. Also a lil more info on your car could help others give you some ideas I assume its a 13B turbo and you have supporting mods if your running a AFC

01-12-2009, 04:03 PM	#9
Kenny Senter The Newbie Join Date: Sep 2008 iTrader: (0) Posts: 27 Rep Power: 0	havent really done much at all in way of checking things, as crappy as that sounds. There is just so many different things it could be. The air intake tube is fine. Doesnt look to be any fuel leaks. I swear its acting like a fuel issue, like its flooding or something. I was gonna get online and order some parts from mazdatrix and just start throwing parts at it, but then I got to the prices...HOLY HELL! Anyway, if it dies I can turn the key over and about 8-10 seconds into cranking it will start to sputter to life but if I even think about touching the accel. pedal it totally kills any progress, lol. Switching the fuel pump off does seem to help slightly but of course doesnt crank and same symptoms when pump is switched back on. Once it finally does crank, it runs like a damn champ...until next time of course. Any other options for a fuel pump, FPR, Air Bypass Valve (idle surge every now and then, but small 830-550ish), Airflow Meter (FRIGGIN $900!!!, screw that!), etc etc? unfortunately, not tail light related, lol. I am gonna check all the connections on the SAFC again, but I really dont suspect it, but never know at this point. Just want my damn car to run reliably again, hahaha, rx7 = reliable?