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New sparks - started fine, died, wont start

2K views 22 replies 5 participants last post by  white93gt 
#1 ·
Installed all 6 sparks with new NGK Iridiums yesterday, along with a new IAC and it started just fine and test drove just fine. Now today after 5 minutes it bucks and stalls. Started back up just fine but then did it again a few more times. Got it back to the garage and popped the hood and watched it for a few minutes until it bucked and died again, this time with the car not moving. Now it won't even fire back up. It tries sometimes but just sputters and dies out. I swapped the old IAC back in but it still won't start up at all.

If it was just a faulty plug, wouldn't it fire up and just misfire like a b*tch? All wires have a good connection to the coil pack, but don't want to rip it all back apart to get to all the sparks until I have a plan.

ANY advice is welcomed!!
 
#3 ·
So when your ECU went, the car bucked and stalled check engine light came on, but then it started right back up and the check engine light went off... and drove for a little while and then same thing... started back up and after a minute same thing... then when the car was not moving it died and won't start again... just want to be sure that we are talking about the same symptoms...

And all of it coincidentally happens when I switch out the spark plugs and IAC? Or might that somehow have caused it? I've never had to deal with a bad ECU before :(
 
#9 ·
....And all of it coincidentally happens when I switch out the spark plugs and IAC? Or might that somehow have caused it? I've never had to deal with a bad ECU before :(
My ECU didn’t even smell and signs of leakage were questionable. I just replaced capacitors because of known failures of capacitors in 1g units and more or less considered it maintenance item at that age. But car started right up with no more problems.

Yes, symptoms were very close with exception I don’t recall a (CEL) indication. If I can find my old post I will post link below. It could easily be coincidence about plugs and IAC; engine will run with IAC unplugged and with some spark plug wires removed.

There could be something else causing problem but if ECU didn’t fail, you can count on it happening in near future if it still has original capacitors in it. So replacing them will not be a waste of money, it will either cure your present problem or save you from future problem.

Read post #6 in this link describing my symptoms:
http://www.3si.org/forum/f1/ecu-capacitor-question-634001/
 
#5 ·
Have you made sure everything is plugged in? MAF, CAS, spark plug wires on the correct coils? If the inside of your ecu smells like rotten fish, you know you have a problem...

Also side note: How do you like that aluminium flywheel? Does it chatter at all?
 
#6 ·
Haven't ever had to dabble with my ECU before, so I'm not even sure where it is. I will google around and see if I can find where to get to it, if it's a 10 minute thing then I don't mind cracking it open and taking a sniff.

I have double and tripple checked that everything is plugged in. I thought maybe something was coming loose when I was driving and was planning to wiggle them with the car idling in the garage but it died before I had the chance to touch any of them and now it won't restart.

So majority opinion right now is ECU, any other ideas at all?? I mean, isn't that extremely coincidental? Could it be the coil pack?
 
#8 ·
I don't think it has to be the ECU, its just an easy spot to start because you could spend a whole year searching for the problem and it might end up being the ecu. If you pull off the panel by your right foot while sitting in the driver seat, you will see the ecu under the radio kinda.

There is 2 screws on the driver side and one screw on the passenger side. then unplug it and pull it out of the car. It can be a pain to unlpug but after that its easy.
4 screws hold the case over the actual ecu board, unscrew them and have a sniff and look for fluid leaking from the cylinder capacitors all over the board.

The real guide
http://www.stealth316.com/2-ecmremoval.htm
 
#7 ·
Shane - missed your side note - the alum flywheel was a great upgrade. I didn't get any chatter until the second clutch, but majority vote there is that the chatter is coming from the throw out bearing. Only hear it at idle and when I put the clutch in the chatter stops.
 
#10 ·
Really good feedback everyone. I'm going to pull the ECU and have a look. The car does have 300k miles on it, and it's on the original ECU. I'll be sure to update with pix after I pull it...

In the meantime... who do we all recommend getting replacement ECUs from these days? I usually like 3SX but $1200 for an EOM replacement seems crazy.. any experience with this Jester ECU? If there's a better replacement than going OEM I'm very open for feedback. Thanks all!
 
#12 ·
Looks like only one of the caps is leaking, and it doesn't look "that bad" to me (someone who knows nothing about circuit boards)... I'll be getting a replacement anyways, but can someone tell me if this looks bad enough to cause the symptoms? I'll upload one more pic after this since I can only do 3 per post.
 

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#13 ·
Couple more pics
 

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#14 ·
Also, I need the car on the road (as I'm sure do we all), so I don't have time to send it in for repair. So I need a new one like ASAP. Any recommendations on source? Thoughts about aftermarket versus OEM?
 
#15 ·
Yeah that C105 looks to be leaking and those are the originals. You can’t tell if bad enough to cause problem visually unless something is burnt up. My ECU didn’t appear any worst than yours, but it shut engine down and was corrected by only replacing the four barrel capacitors you see on your board, coincidently which is same unit as mine MD190662.

Shoot you could even buy these:
ECU CAPS Capacitors SET*-*Mitsubishi 3000GT*/*Dodge Stealth Parts

And have local electronic repair shop replace them on your board. However places like Ninja Performance has test bench to test all components, but they will automatically replace those four capacitors.
 
#17 ·
There are a handful of people selling used parts that would have one for sale. Post in the parts wanted section.

Another company that repairs and sells these ECU's is ECM to go in TX. I have used them before and they seem to be quite knowledgeable about our cars.

-SP
 
#18 ·
Can anyone tell me what the other info on the sticker means? Should I be worried if the replacement doesn't show "2x23" or "M" at the bottom? There's some used ones that have the same part number but I'm worried there's some logic in here for the RT versus the base model that might be missing or something...
 
#20 ·
Thank you for your help! I found that autozone had this one that they could get next-day, hope it works!
Product Detail
 
#22 ·
With the replacement ECU installed the car fired right up and the test drive around the block went great! Good call there and thanks everyone for the assist! I am pretty sure that piece-by-piece I'll eventually replace everything and the car will be like new again haha
 
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