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runs good then dies then starts right up??

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jonathanmaples

Probationary Member
7
0
Feb 25, 2009
waxahachie, Texas
i have a 96 eclipse rs 420a with a 5 speed,, it will run great for a little bit then the tack and speedo drop to zero and everything dies just like as if i turned the key off while driving. its gotten worse since it happen the first time i could drive it to the gas station and back now it doesnt run long enuf to get out of my driveway. after it dies it will not restart till i turn the key off and let it sit for a few seconds,, but after that it will start and run fine like nothing happen. no smoke, no noise, no lights,, i checked my fuel pressure and its at just over 50 while its running. it has spark on all four cylinders, it has 165 lbs of compression across the board. i thought it was a bad batt cable so i replaced both terminal ends but to no avail. i scaned it with my scanner and it pulls no codes but theres also no check engine light on either its a fairly new motor was rebuilt like 3 months ago but i reused the old sensors. im starting to think pcm but i dont like that theory i am hoping for someone to shout out and say hey i had the same problem and all i did was ________. does it worse after running for 10 mins.

i would appreciate it if you could email me [email protected]
 
ok i took off work today to figure this out (also due to the fact it is my way to work). ok this is what ive found so far i went ahead and put a new crank and cam position sensors on it runs great for a lil bit then the gauges drop off and the engine dies so i started looking more into it the fuel pressure is still good when it dies so i marked off the fuel pump, i opend up the harness to search for broken or burned wires and found nothing no breaks burns or anything other than stock harness, checked the voltage its putting out 13.7 which i'm assuming should be fine with the radiator fans on. i checked the ground on the cam sensor and its fine i checked the yellow wire on the cam sensor and it has 5.15 volts but soon as it dies it drops to 0. i traced the wire no breaks gounding out or burns. i think the pcm is toasty?? anything else i should check before i hit the junk yard for a new pcm?
 
umm well i dropped a new pcm in it just now it started right up but did the exact same thing as earlier run for a lil bit then just die it will not start back up untill u turn the key off for a sec then back on and it will start just fine. im lost,, ima go back threw the harness again to see if i missed a wire or some thing i jiggled the harness next to where it plugs into the pcm and it dies almost immeadtly.
 
my 97 did this a while back and I tried a billion things before I finally took it in and had it looked at and it ended up that it was a wiring issue and needed a new ecu. You might be able to go get like a junk yard ecu and try that and solve your issue. Hope this helps. If not, good luck finding the cure. At least you know when you do figure it out, you'll know for next time, DSM'ers are some of the best mechanics due to having to fix the car every 44 minutes, haha. good luck my friend.
 
ok guys this sounds a lil sketchy let me know what you think ok during all this harness searching and recoving i found that the fuel pump relay and asd/mfi relay were both corroded so i cleaned them both i made shure the harnesses where all clean and connected at the right spots. i noticed that i was half a quart low on oil so i toped it off. now it runs fine i let it run for like an hour at idle just to make shure it wasnt gonna just quit on me or overheat, ect. any way u guys think that could be it bad connections. or maybe when i changed my oil pan last week the cheap oil i threw in it just doesnt hold up well with heat( like the car warms up it thins out and loses oil pressure the pcm shuts it down due to lack of oil pressure?? any way im going to put the air cleaner back on, finish eating and go drive it down the road a lil bit and see what happens.
 
ok the eclipse is killing me it ran fine all night last night i drove it to town back and around just because got it out on a back road and drove the crap out of it no problems. i started to go to work this morning i didnt make it 2 blocks before it died on me again no codes no mil light. i got home from work today and it sputterd down to the house and after running for bout 15 mins its cleared up currently running great in my driveway im so confused??checked the relays fuses and such nothing amiss fuel is good still spark is still good compression is at 160 on all cylinders im lost. im going to jack it up and see if anythings hanging lose like a second o2 sensor?
 
well first i trailered it up and brought it to a local mitsu dealer to hook it up to the diag machine they hooked it up ran it and reran it the car did the same thing to them it did to me ran fine, died randomly then started right back up all while on there machine while logging the sensors after 3 hours of watching them go threw the same test i went through they told me its ###### a short in the harness some where the best thing tey would recomend was buying a new harness.. REALLY THAT'S THE BEST YOU COULD COME UP WITH! they couldnt even explain why they thought that or back up there claim that the harness is bad. so i trailed it home after not paying for a bad diagnostic session. Any way long story short i looked more into the wiring that goes to the cam and crank sensors i found that on my car the cam pos and crank pos draw there power threw the vechial speed sensor (vss) so i when ahead and just grabbed a new one. lucky me it starts right up and runs great without randomly dieing.


vss is the verdic
 
have you tried injector cleaner.?? this happend to my taurus and we threw some injector cleaner in the tank and she stopped it! hope that helps
 
appreciate the help but i found it. it was the vss sensor it had a intermittant short in the sensor itself that would cut the power to it and the cam and crank sensors causing the pcm to hit the asd relay cutting off everything all at the same time. thats also the reason after i turned the key to off for a sec and back on it would start right back up and run fine (till the sensor effed up again). cycling the key off and back on again would reset the asd relay and the computer wouldnt know anything was wrong when it just starts back up and runs fine (mitsu's explanation of the no codes).

ps the speedometer was working. just because it was working doesnt mean it was working right! the odometer and tripometer was not working but now they are..

thanks anyway guys.
 
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