Mitsubishi 3000GT & Dodge Stealth Forum banner

1 - 20 of 32 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
For the first time in 28 1/2 years my Stealth won't start, I went out with it yesterday June 18-2020 all normal, came home, parked it in the garage as usual. This morning I wanted to go out with it but to my surprise no start, it cranks but no go, battery is brand new and I even connected a booster but no luck. The car is spotless, never seen a winter, never went out when raining, It could not be rust related. It usually starts on the first turn of the key even after it was sitting for the winter. I have contacted my mechanic and he suggests could be the fuel pump or the spark plugs but from reading similar posts in this forum it could also be electronic related. The car is going in next week but in the meantime any suggestion is appreciated and I could relay it to my mechanic, he is very good but he has never worked on a Stealth. Thank You
 

·
Senior **i.e. OLD** Member
Joined
·
13,415 Posts
Hrmm...
My first thought is have the capacitors in the ECU ever been replaced? 1g cars are NOTORIOUS for having leaking electrolytic caps in both the ECU and ECS computers.
Secondly, have you checked all the fuses? Both under the hood and under the dash.
I am assuming the lights and other electronics work?

Bob.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #3 (Edited)
Hrmm...
My first thought is have the capacitors in the ECU ever been replaced? 1g cars are NOTORIOUS for having leaking electrolytic caps in both the ECU and ECS computers.
Secondly, have you checked all the fuses? Both under the hood and under the dash.
I am assuming the lights and other electronics work?

Bob.
Thank You for your quick reply Bob. What are the fuse label I should be looking for?
No the ECU capacitors have never been replaced, the only thing I ever had to replace is the item on the photo also did the 60K maintenance kit and that's about all other than regular maintenance. The car has 101,000K
288672
 

·
Senior **i.e. OLD** Member
Joined
·
13,415 Posts
That is the computer for for your keyfob doorlocks.

Underhood Fuses:

288673


Since it cranks, I wouldn't think it would be one of these, but I would still check 4 and 6 (I don't think you would have ANYTHING without #1)

Under dash fuses:

288674


Biggest suspects here would be 1, 12 and 19

Hope this helps...

Bob.
 

·
Senior **i.e. OLD** Member
Joined
·
13,415 Posts
If your feeling like you want to tackle this, you can pull the ECU and check for damage (leaking capacitors, funky fluids on the PCB)


Bob.
 

·
Senior **i.e. OLD** Member
Joined
·
13,415 Posts
If nothing else, you can share that link with your mechanic....

Bob.
 

·
Senior **i.e. OLD** Member
Joined
·
13,415 Posts
It could be other things as well....

Fuel pump could be bad.
MFI relay could have failed.
Not likely, but the PTU could have totally failed (normally just one of the three circuits inside it fail and cause rough (very) conditions...

Bob.
 

·
Senior **i.e. OLD** Member
Joined
·
13,415 Posts
I'm sure others will chime in with more ideas...

Bob.
 

·
Registered
93 NA ATX 3000gt DOHC
Joined
·
1,993 Posts
Bob (OhioSpyderman) has already cover most of the more common areas, I’ll simply add you might also check the 20amp #1 dedicated fuse circled in red as it feeds power to the MFI relay and engine will not start without that power. Its most likely marked ECI on box cover.
relay box.JPG
Click on image to enlarge
 

·
Registered
Joined
·
369 Posts
TUrn key on and see if check engine light come on, do not crank.




If you don’t see it light up, try a spare ECU
 

·
Registered
Joined
·
13 Posts
Discussion Starter #12
TUrn key on and see if check engine light come on, do not crank.




If you don’t see it light up, try a spare ECU
Thank You Ohio Stealth, I checked all the fuses and they all appear to be ok'
When I turn the key on, the check engine light is not there, would that mean an ECU problem?.
Unfortunately I have no idea where to get one, if someone can help I appreciate and based on the information
that Bob provided I can probably change it myself. I think i'll wait before sending it to the mechanic. I hope is ok to post a picture, if not I apologize and will remove it. Thank You
288684
 

·
Registered
1991 Dodge Stealth Base SOHC ATX
Joined
·
80 Posts
I had a crank-no start condition on my base model recently, another thread helped me discover the ecu was the issue. If you decide to replace the ECU, I would suggest that your mechanic check the IAC servo to make sure it isn't shorting like it was on my car. That is what caused my ECU to go, and would cause the new one to blow right away as well.
 

·
Senior **i.e. OLD** Member
Joined
·
13,415 Posts
As luck would have it, I just sold my 2 spare MD159966 ECU's after selling my 92TT last Sunday :(

Checking the IAC is easy, all you need is a meter that accurately measures resistance...

288685


Basically, what this drawn out explanation is saying is place one lead of the meter on pin 2, the put the other lead on pin 1, write down the Ohm measuremet
Then move the lead from pin 1 to pin 3 (keeping the other lead on pin 2) write down the Ohm measurement
Then move the lead from pin 2 to pin 5, put the other lead on pin 4, write down the Ohm measurement.
Lastly move the lead from pin 4 to pin 6 and write down the Ohm measurement.

All 4 of your readings should fall between 28 and 33 ohms (give or take a few ohms).
If any of the readings are wildly off, then you IAC is probably bad.

Bob.
 
  • Like
Reactions: stealthcart

·
Registered
93 NA ATX 3000gt DOHC
Joined
·
1,993 Posts
When I turn the key on, the check engine light is not there, would that mean an ECU problem?.
Not necessarily a positive indication of bad ECU, as it could be bulb burnt out or even 15 amp #11 fuse that you might not have checked yet (see OhioSpyderman’s post #4 for box location). But as already mentioned more than once ECU failure is common with these early platforms.

One thing you might do is unplug the ECS as they have been known to cause problems with ECU operation. To see if that corrects starting problem, located inside right rear quarter panel.
ECS.JPG

my mechanic, he is very good but he has never worked on a Stealth. Thank You
This gives me pause as it appears to be an electrical problem; he not only would have to be proficient in electrical troubleshooting, without him understanding how many of the electrical problems are unique to this platform he may get lost.
 

·
Registered
Joined
·
369 Posts
I dont think the check engine light problem is a only Burnt bulb because the car would start,


You recently put a new battery in it, probable putting the aged ECU circuit board over the hill by circumstance.....


ECU can be rebuilt for only 100$. Dont even bother with a testing with a ECU replacement, take old ECU out yourself and ship it off. (Make Sure repair man check for corrosion and replace caps.




'
 

·
Registered
Joined
·
13 Posts
Discussion Starter #17
Hello guys, really appreciate your help.
I have disconnected the ECU myself, i opened it up and it appears to me that everything is in good shape no sign of any corrosion, here is some photos, don't know what to do next? I have disconnected the ECS, the only other thing i have not tested the IAC because i am not sure where is located.
288755
288757
288758
 

·
Senior **i.e. OLD** Member
Joined
·
13,415 Posts
The IAC won't keep the car from starting, but it can destroy an ECU if fails. I agree that your ECU looks clean.
Well, do you have a spark tester?
Just because the ECU looks good, it doesn't mean that you have spark.
Once you've determined you have spark, the next step would be fuel.
You can pull a plug after a bit of cranking and see if the plug is wet or dry. Dry could be a dead pump, badly clogged fuel filter....

Sucks when out of the blue something that's been working for years says "sorry, not today"....

Bob.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #19
The IAC won't keep the car from starting, but it can destroy an ECU if fails. I agree that your ECU looks clean.
Well, do you have a spark tester?
Just because the ECU looks good, it doesn't mean that you have spark.
Once you've determined you have spark, the next step would be fuel.
You can pull a plug after a bit of cranking and see if the plug is wet or dry. Dry could be a dead pump, badly clogged fuel filter....

Sucks when out of the blue something that's been working for years says "sorry, not today"....

Bob.
Thanks Bob for your reply, i have replaced the fuel filter last year, found an original one. I don't have a spark tester but that could be out of my league, i wouldn't know how to test the spark. Maybe i will look for a used ECU with the same number and try it, if that won't go then will look at the fuel pump, and i don't mind keeping the ECU as a spare.
 

·
Senior **i.e. OLD** Member
Joined
·
13,415 Posts
Damnit.
Just last week I sold both of the spare ECU's I had for my 92TT that got sold a week ago Sunday.

There is the non-mechanics way of testing for spark (but I would wear LEATHER gloves).
You can have someone crank the car and then singularly pull the plug wire from the top of the coil, the spark should jump from the wire to the coil (if you keep it about 1/4" away....).
I would do all 6, but there's probably a good chance if you have spark at one, you have spark on the others (not 100%).

I need to do a little research on how to tell you to test pump circuit. I know there is a wire near the battery that you can supply with 12 volts to see if the pump comes on....need to find that pic....

Bob.
 
1 - 20 of 32 Posts
Top