View Full Version : Random Power/Ignition Loss and Shutdown

02-18-2008, 02:43 AM
Here are the stats...

95 S14
sr20det (vtc)
Greddy Emanage Ultimate
300zx MAF and Ignitor
WideBand o2
550cc injectors
New Optima battery
New Plugs
Fresh Oil

Car was not driven for about 4 months for various reasons...Decided to get it going again. Replaced battery. Drove perfectly fine for about 4 days - left work early in the morning (somewhat colder temps then normal) went to the gym while parking the motor basically died...almost like i was going too slow and let the clutch out too soon and the enging cuts off. Turned the key and the car cranked back up (though i just made a shifting error) Leave the gym and drive approx. 10 miles home -

About .5mi. from the house same thing happens except this time im in higher rpm not speeding just lightly spirited gas bump - basically there was no way i could have just slipped the clutch. Engined dies again...try to crank (with clutch pushed in an rolling) but motor will only turn over - will not fire. Try to release clutch while still rolling to "pop" the clutch - still will not pop start either.

Im able to pull to the side - wait for about 10 minutes - after 2 or 3 tries (along with some very loud backfires) car fires back up again. This time i drive maybe 200yards and the car dies again (only thing i can equate it to is the same feeling as when your driving and just turn off the ignition by the key - like it almost sounds like the car should be running but if you step on the gas pedal nothing happnes.)

I repeat the 10 minute wait process until i can get the car to the house....

A few days later my friend gets a 240 (same basic setup) and wants to take my harness out to copy it for his car....He does this and last night we put the harness back into my car... Car cranks and runs on the first try with no issues...In fact it idles even better then before.

I drive the car back down the street about 1/2 mile and the exact same proble again.

Most logical thing i could think of was what the ignitor is maybe overheating somehow or dying out after X amout of time...???


02-18-2008, 09:10 AM
same thing happened to my buddy derek's 180sx. he replaced everything, relays, ecu's, dc'd the turbo timer. still would just die for no reason.....ended up being the maf.


02-18-2008, 11:55 AM
ok...so then i should get a bad MAF voltage right? - i think i have an extra one so ill try that first -

still looking for possible remedies....:confused:

02-18-2008, 04:27 PM
his car ran perfectly fine 90% of the time, never was hard to rev passed 3 grand like the typical bad maf scenarios.....then sometimes cold sometimes when the car was warmed up (it didn't matter) he'd be going down the road and it'd just die....he'd try to start it back up and it'd just turn over....he'd wait a second. turn the car all the way off, then it'd start back up. 90% of the time the car would run perfectly fine. it'd rev to 7200rpm no problem etc etc. then for no rhyme or reason it'd just die.

like i said, he replaced EVERYTHING, i was scratching my head trying to think of something it could possibly be because i never saw a defective/bad maf produce those symptoms before. finally he just got fed up and said, aiight lemme try another maf, and voila. before the maf he tried , ignitor, cas, relays, ecu's, coolant temp sensors, o2's dc'd the turbo timer, dc'd the boost controller, knock sensor....then he remembered it started doing it ever since he got his maf.....so he put in another maf, and never had the problem again.

i was like wtf....maf's don't make the car do that....but in his case...it did so...figured since i'd seen some crazy shit that was costly for him to diagnose, i'd offer the advice.

worst case, just try your stock maf or a different maf for a week and see. seriously,
Dave =]

02-18-2008, 05:04 PM
Injectors flooding the cylinders?

02-19-2008, 01:08 AM
Trust me its most likely you got a bad igniter chip test that first.

02-19-2008, 06:58 PM
Trust me its most likely you got a bad igniter chip test that first.

yeah...im gonna try my friends 300z ignitor and see what happens ...btw i checked my maf voltage and it is idling at around .8 - .9...its been a long time since i had to worry about maf voltages....but that is about where it is supposed to be right???

02-19-2008, 10:20 PM
i hope the ignitor fixes it.....

it's kind of hard to check a patient for high blood pressure when they walk in your office and his blood pressure is normal. what i mean by that is, on an intermittent problem you have to make your diagnosis while it's exhibiting the symptoms. if everything's doing what it's supposed to do, you won't find a problem...cause everything is doing what it's supposed to do. maf voltage changes, it's a 0-5volt reference.

i'm not saying when ur car dies run out with your multimeter and do a pin point test on your maf.

i'm saying i hope the ignitor fixes it, if not try your stock maf or another whatever you're using maf for a week and see if it doesn't act up anymore
Dave =]

03-15-2008, 02:36 PM

ok...since my last post the following has happened.....

Pulled the entire harness out for a friend to look at everything was good....put the harness back in...exact same problem happens. Then I went out of town for a week...came back and tried to start the car but now it wont start at all!!! this is what ive done to try to fix it.

tried 3 different ignitors, just tried a new cas, took out harness to check for issues, checked all grounds, checked all voltages at cas, checked voltages at ecu, checked voltages at maf, checked ground at ignitor. when i pull the plugs they are wet with fuel

this problem seems like it should be SOOOOOO simple to resolve but ive tried all ideas i have read about on here but i still cant figure it out!!!!!!

last thing i can think of is to pull the harness and soder all the connections but i am already for sure that everything is getting the power that it should.