Intermittent Stalling Issue at Idle
04-09-17, 10:24 AM
#1
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Intermittent Stalling Issue at Idle
Hi guys,
I've been having an intermittent stalling issue and figured I'd get some insight before i start throwing parts at the car. First happened while leaving a large car meet, took 30 minutes to get out. Car was running fine then suddenly died waiting in the line. Started her back up and immediately died again. Finally got out of there and a quick blast down the highway and she was idling fine again.
2 days later it died sitting in my work parking lot and today it died coming off the highway. A quick run down the highway did not fix it this time.
My thought is that since it wouldn't start last week before the car meet, suspected flooding, that i probably need to just put new plugs in but I wanted to hear what you guys think.
Thank you.
I've been having an intermittent stalling issue and figured I'd get some insight before i start throwing parts at the car. First happened while leaving a large car meet, took 30 minutes to get out. Car was running fine then suddenly died waiting in the line. Started her back up and immediately died again. Finally got out of there and a quick blast down the highway and she was idling fine again.
2 days later it died sitting in my work parking lot and today it died coming off the highway. A quick run down the highway did not fix it this time.
My thought is that since it wouldn't start last week before the car meet, suspected flooding, that i probably need to just put new plugs in but I wanted to hear what you guys think.
Thank you.
04-09-17, 12:26 PM
#3
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I'll look into a compression test. Plugs are relatively new but could be fouled from all the extra oil i pumped in for compression, starting the flooded engine.
04-09-17, 08:50 PM
#4
a possible leaking injector should be considered. its free and easy to check. these things do just............ happen -___-
unbolt the fuel rails and prime the fuel pump from the diagnosis box.... watch the injectors for fluid. simple, quick, easy. i had an issue recently with my car where it would have trouble starting and it had all the symptoms of a flood but it ended up being the o-ring at the fuel pump on the hanger. it wasnt sealing like it was supposed to. i thought it was strange since after driving the car X amount of time, i would shut it down and it may or may not start back up. i thought it was a leaking injector because even if i didnt start the car, as in i just primed the pump and left it, it wouldnt start. i had to give it a kick with some carb cleaner in the UIM through where the bov attaches. it would start everytime that way. 100%.
so i guess check that too. maybe youre loosing fuel pressure. as rotaryevolution mentioned, a compression test wouldnt hurt. the implication of one is a little menacing when troubleshooting so personally, its my last resort. although it makes more sense for it to be the first. there isnt much progress to be made troubleshooting a blown motor....
unbolt the fuel rails and prime the fuel pump from the diagnosis box.... watch the injectors for fluid. simple, quick, easy. i had an issue recently with my car where it would have trouble starting and it had all the symptoms of a flood but it ended up being the o-ring at the fuel pump on the hanger. it wasnt sealing like it was supposed to. i thought it was strange since after driving the car X amount of time, i would shut it down and it may or may not start back up. i thought it was a leaking injector because even if i didnt start the car, as in i just primed the pump and left it, it wouldnt start. i had to give it a kick with some carb cleaner in the UIM through where the bov attaches. it would start everytime that way. 100%.
so i guess check that too. maybe youre loosing fuel pressure. as rotaryevolution mentioned, a compression test wouldnt hurt. the implication of one is a little menacing when troubleshooting so personally, its my last resort. although it makes more sense for it to be the first. there isnt much progress to be made troubleshooting a blown motor....
Last edited by cr-rex; 04-09-17 at 08:56 PM.
04-10-17, 12:01 AM
#5
did you just say checking the injectors was quick and easy? you do know some people still have stock cars right? i know what i am doing under there and and i still hate working around the rat's nest. there is nothing quick or easy about it.
a compression test is a last resort? its the quickest mother effing test one can perform, it's also the last..... because people hate the results and would rather waste time doing stupid menial ****.
personally, if you want to know if an injector is leaking just let the car sit overnight then remove the egi fuse, crank it for a second and remove the lead plugs, if theyre sopping wet with gas then yeah. however injectors don't always leak during a test, it is a random occurrence when leaky injectors do actually leak. so putting them on a flow bench is about the best way to verify them, which means just sending them off for servicing. so yeah, i'd rather waste time doing a compression test as a first test, instead of a last one.
why do i have to be the bad guy to tell people that rotary engines are god damn unreliable? i hate it too, but at least i don't lie to myself everytime i glance at my car and whenever doing any work try to make my life even more inconvenient by doing all the wrong tests first.
i'll be honest with you because apparently no one else will. of all the times i had an FD stalling issue, it usually was due to compression imbalances/low compression. i may be wrong, and i hope i am for your sake but i hate seeing people steer others away from the wind, even if there is a storm on the horizon.
a compression test is a last resort? its the quickest mother effing test one can perform, it's also the last..... because people hate the results and would rather waste time doing stupid menial ****.
personally, if you want to know if an injector is leaking just let the car sit overnight then remove the egi fuse, crank it for a second and remove the lead plugs, if theyre sopping wet with gas then yeah. however injectors don't always leak during a test, it is a random occurrence when leaky injectors do actually leak. so putting them on a flow bench is about the best way to verify them, which means just sending them off for servicing. so yeah, i'd rather waste time doing a compression test as a first test, instead of a last one.
why do i have to be the bad guy to tell people that rotary engines are god damn unreliable? i hate it too, but at least i don't lie to myself everytime i glance at my car and whenever doing any work try to make my life even more inconvenient by doing all the wrong tests first.
i'll be honest with you because apparently no one else will. of all the times i had an FD stalling issue, it usually was due to compression imbalances/low compression. i may be wrong, and i hope i am for your sake but i hate seeing people steer others away from the wind, even if there is a storm on the horizon.
Last edited by RotaryEvolution; 04-10-17 at 12:15 AM.
04-10-17, 12:28 AM
#6
I agree with Rotary Evolution, most times its a compression thing- an emerging symptom of time for a refresh, etc.
However,
just to give you that little bit of hope before you go down the injectors and compression path, I had intermittent and unreliable stalling issues a few years ago just like you describe. I had a stock ECU and was able to pull a fault code via the LED, resistor in the Diagnosis plug under the hood (JDM car with no check engine light like the USDMs) and it told me the coolant temp sensor had gone open circuit intermittently.
If the car gets faulty signal or no signal from the coolant temp sensor, it will shut off and stall at any rpm. Mine was doing it at idle, at traffic lights and at low speed. I replaced the coolant temp sensor and the fault code went away and the car never stalled again. So it does pay to have a look at that.
However,
just to give you that little bit of hope before you go down the injectors and compression path, I had intermittent and unreliable stalling issues a few years ago just like you describe. I had a stock ECU and was able to pull a fault code via the LED, resistor in the Diagnosis plug under the hood (JDM car with no check engine light like the USDMs) and it told me the coolant temp sensor had gone open circuit intermittently.
If the car gets faulty signal or no signal from the coolant temp sensor, it will shut off and stall at any rpm. Mine was doing it at idle, at traffic lights and at low speed. I replaced the coolant temp sensor and the fault code went away and the car never stalled again. So it does pay to have a look at that.
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04-11-17, 09:51 AM
#10
did you just say checking the injectors was quick and easy? you do know some people still have stock cars right? i know what i am doing under there and and i still hate working around the rat's nest. there is nothing quick or easy about it.
a compression test is a last resort? its the quickest mother effing test one can perform, it's also the last..... because people hate the results and would rather waste time doing stupid menial ****................
a compression test is a last resort? its the quickest mother effing test one can perform, it's also the last..... because people hate the results and would rather waste time doing stupid menial ****................
in my experience, its always been something else. i would rather spend time troubleshooting components than go through the trouble of getting a compression test done and spending that money to be shown something i already know. if i can take the plugs out and rotate the motor and hear all the hissing nice and healthy, then thats good enough for me to move on. depending on the symptoms, i will go through all applicable components then work my way outward. even with a chipped seal or a broken/cracked corner seal, the car will still start. depending on the symptoms, calling the motor bad may be the outcome.
we all do things differently and where some may start with a compression test, others like myself work up to that.......... depending on the symptoms. its a method thats worked for me for the past 5 years and until i get my own tester, i dont really see a need to change.
04-11-17, 10:51 AM
#11
RX-7 Bad Ass
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People are getting too carried away with compression tests. This isn't something you need a specialized rotary engine tester for.
Yes, a rotary tester will give some better information, but a standard tester will tell you the big news.
Get a $30 tester from the auto parts store. Unscrew the schrader valve at the end that screws into the plug hole. Disable fuel and spark, floor accelerator, crank. You will see the needle spike with compression pulses. If you see low-low-HIGH, that's a broken apex seal. HIGH-HIGH-low is a corner or side seal issue. Even pulses and the motor is happy. All low and you have a real problem.
Vacuum at idle is a big indicator of motor health. 10" of vacuum is a weak motor, 20" is crazy strong. Really anything 14-15" and higher is good.
Dale
Yes, a rotary tester will give some better information, but a standard tester will tell you the big news.
Get a $30 tester from the auto parts store. Unscrew the schrader valve at the end that screws into the plug hole. Disable fuel and spark, floor accelerator, crank. You will see the needle spike with compression pulses. If you see low-low-HIGH, that's a broken apex seal. HIGH-HIGH-low is a corner or side seal issue. Even pulses and the motor is happy. All low and you have a real problem.
Vacuum at idle is a big indicator of motor health. 10" of vacuum is a weak motor, 20" is crazy strong. Really anything 14-15" and higher is good.
Dale
04-13-17, 12:00 AM
#12
what ^ said
everyone who owns a rotary car and does anything more than oil changes should at least have a basic compression gauge handy. the inevitable happens to all of us, and it just saves worthless running around checking everything except the engine, which the engine isn't already notably the most reliable one ever built.
everyone who owns a rotary car and does anything more than oil changes should at least have a basic compression gauge handy. the inevitable happens to all of us, and it just saves worthless running around checking everything except the engine, which the engine isn't already notably the most reliable one ever built.
Last edited by RotaryEvolution; 04-13-17 at 12:04 AM.
04-13-17, 05:02 PM
#13
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I'm in the middle of a Unit Effectiveness Inspection at my base so I'm having trouble finding free time to troubleshoot.
I do know the vacuum which when warm it is sitting around 420 mmHG or 16.5" if my math is correct.
I do know the vacuum which when warm it is sitting around 420 mmHG or 16.5" if my math is correct.
04-14-17, 03:24 PM
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