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1G Eagle Talon TSi not starting (was fine the day before)

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
I'm currently in the process of restoring my 1993 Eagle Talon TSi, and have been working to diagnose an engine stutter under hard acceleration. Well after driving it around my neighborhood a few times, I parked it and left it overnight. The next morning, it would not start at all. The starter motor would go without any hint that it wanted to turn over. We found that the spark plugs were not getting any spark, and it didn't seem like there was any pulse coming from the injectors (fuel rail was getting plenty of fuel, however). My brother cleaned the spark plugs and replaced the coil pack. After the install we tried to start it up again and were met with the same result - it still wouldn't start. I noticed that there was corrosion on the spark plug wires and somewhat in the spark plug cavities as well. I was thinking maybe it could be the spark plug wires, but how could they all stop working overnight?

After doing some research, I found a few possible issues that could cause these symptoms:
1) Bad power transistor
2) Bad crank angle sensor
3) Bad cam angle sensor

I don't believe the check engine light was on, but I haven't scanned it so it could have codes. Do y'all have any other suggestions?
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
I'd swap the power transistor first, they're pretty common to go bad after 25 years. Also referred to as the (ignition control module).

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Yeah I think I'll do that. Thanks for the picture!
 

ErikTande

Supporting Member
1,426
415
Dec 17, 2012
Centennial, Colorado
Yeah I think I'll do that. Thanks for the picture!
That pic is from a 1990, the 91-94 are a little different if I remember correctly. But yeah, I'd swap that first.

Mine did the same thing, just died one day. Took me forever to figure it out.
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
That pic is from a 1990, the 91-94 are a little different if I remember correctly. But yeah, I'd swap that first.

Mine did the same thing, just died one day. Took me forever to figure it out.

Where's the best place to find a replacement? RockAuto is charging almost 150 dollars:boring:
 

ErikTande

Supporting Member
1,426
415
Dec 17, 2012
Centennial, Colorado
Where's the best place to find a replacement? RockAuto is charging almost 150 dollars:boring:
Yeah, they're not cheap. Even an non-oem one from autozone or other parts store is gonna be at least $100. Good news is most parts stores have them in stock.
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
Finding them for about 17-30 dollars on eBay...Looks to be the right one too, says it will fit a 1993 Mitsubishi Eclipse
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
Bought a power transistor for 15 dollars on eBay, I hope it works!
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Red_EcliPzE_GsX

Proven Member
124
38
Nov 25, 2002
Irving, Texas
Should do the trick, same thing happened to me. After swapping it out, if the check engine light comes back on for a few seconds and the stock boost gauge needle jumps to zero when turning the ignition to on, it should def fire right up.
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
I was finally able to replace the power transistor, however, the car still isn't starting up and still isn't getting spark. The fuel pump is running. Something I noticed was the engine light isn't coming on at all when I am cycling the ignition, now this might just be because the dash light for it is burnt out, but I heard that can be an indication that your computer isn't functioning properly. I think it could be the Cam/Crank angle sensor, but that is a little more complicated to diagnose, and I honestly am not confident in how to reset the sensor if I were to remove it. I know you need cylinder #1 at TDC, and to have the notched side of the plate on the sensor aligned with the notch on the sensor all mounted at TDC, however I am not sure how to get cylinder #1 at TDC. I am going to test the signal coming from the power transistor harness as well as the CAS harness today to try to narrow down the source of the problem.
 
Last edited:

steve

DSM Wiseman
13,736
828
Feb 3, 2002
Boulder, Colorado
If the check engine light doesn't come on for about five seconds when you turn the ignition on and the boost gauge doesn't go to 0 then the ECU isn't running. Needless to say the car won't start in that case. You can also check the ECU diagnostic pin to make sure it's outputting a on-off-on heartbeat pulse repeatedly.
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
This is what happens when I cycle the ignition, not sure if it is doing this because of a low battery or not. Also, where is the ECU diagnostic pin?
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1990TSIAWDTALON

Moderator
7,739
3,748
Nov 14, 2013
Independence, Kansas

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
We have already replaced the ECU with an EPROM, so if it's that the car is basically scrap, not going to spend another $500 on something that can't seem to last.
 

1990TSIAWDTALON

Moderator
7,739
3,748
Nov 14, 2013
Independence, Kansas
The guys at ECMLink repair ECU's and are very good and reasonable. If it is a NEW ECU it will be warrantied I would think. An ECU with ECMLink installed in it is about $5-600 so I hope that is what you spent the money on.
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
How much do they typically charge for repairs? And unfortunately, my dad is the one who purchased the computer and it was bought a long time ago. The car has been sitting for awhile so even if my dad can find the receipt I doubt it is still under warranty/:
 

pauleyman

DSM Wiseman
6,559
1,733
Nov 19, 2011
oklahoma city, Oklahoma
We have already replaced the ECU with an EPROM, so if it's that the car is basically scrap, not going to spend another $500 on something that can't seem to last.
The car is old. You said in your originial post you were trying to restore it. "can't last" isn't a fair statement given the cars age. Most repairs are simple but you've got to be willing to put in the time to diagnose. If you had key on in that video your ECU is not responding. Assuming this is a stock chip and you didn't buy ECMlink the boost gauge should zero out and the check engine lights for 5 sec and then shuts off. Diagnosing the ecu shouldn't be hard and you can start at the diagnostic port at the fusebox. The procedures are well documented, easily searchable and easy to execute if you have basic tools and basic skills.
This took me 10 sec to find on google.
https://www.ecmtuning.com/wiki/diagport-12pin
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
No need to be rude, I am just trying to learn how to work on this car and looking to people with more experience to help save me some time. I have a shoestring budget that I can't really help and if a 500 dollar computer is what is broken, I am going to be forced to scrap the car. The cost to fix everything else on top of the cost of a computer that has already been replaced is just too much. I love this car and fully understand that old cars have tons of issues. But I'd like to find a fix I can afford so I can get this car in better shape. I was referring to the ECU when I mentioned "can't last" btw. These cars have a ton of common electrical issues and I am JUST learning about them, it may have been a ten second search for you, but I do not know exactly what I should even be searching for. There is no need to criticize someone looking for advice. Thank you for the link, I have a multimeter and will try to see if I'm getting a pulse.
The car is old. You said in your originial post you were trying to restore it. "can't last" isn't a fair statement given the cars age. Most repairs are simple but you've got to be willing to put in the time to diagnose. If you had key on in that video your ECU is not responding. Assuming this is a stock chip and you didn't buy ECMlink the boost gauge should zero out and the check engine lights for 5 sec and then shuts off. Diagnosing the ecu shouldn't be hard and you can start at the diagnostic port at the fusebox. The procedures are well documented, easily searchable and easy to execute if you have basic tools and basic skills.
This took me 10 sec to find on google.
https://www.ecmtuning.com/wiki/diagport-12pin
 

Vegas Smith

Proven Member
4,442
2,262
Dec 2, 2002
Houston, Texas
No need to be rude, I am just trying to learn how to work on this car and looking to people with more experience to help save me some time. I have a shoestring budget that I can't really help and if a 500 dollar computer is what is broken, I am going to be forced to scrap the car. The cost to fix everything else on top of the cost of a computer that has already been replaced is just too much. I love this car and fully understand that old cars have tons of issues. But I'd like to find a fix I can afford so I can get this car in better shape. I was referring to the ECU when I mentioned "can't last" btw. These cars have a ton of common electrical issues and I am JUST learning about them, it may have been a ten second search for you, but I do not know exactly what I should even be searching for. There is no need to criticize someone looking for advice. Thank you for the link, I have a multimeter and will try to see if I'm getting a pulse.
A new ecu won't run you $500, maybe $100 or less. From the video, it seems like a bad ecu. Where specially do you live in Magnolia?
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
I live on Honea Egypt by FM 1488 if you know where that is
 

pauleyman

DSM Wiseman
6,559
1,733
Nov 19, 2011
oklahoma city, Oklahoma
No need to be rude, I am just trying to learn how to work on this car and looking to people with more experience to help save me some time. I have a shoestring budget that I can't really help and if a 500 dollar computer is what is broken, I am going to be forced to scrap the car. The cost to fix everything else on top of the cost of a computer that has already been replaced is just too much. I love this car and fully understand that old cars have tons of issues. But I'd like to find a fix I can afford so I can get this car in better shape. I was referring to the ECU when I mentioned "can't last" btw. These cars have a ton of common electrical issues and I am JUST learning about them, it may have been a ten second search for you, but I do not know exactly what I should even be searching for. There is no need to criticize someone looking for advice. Thank you for the link, I have a multimeter and will try to see if I'm getting a pulse.
My apologies for my blunt demeanor. 30 years of this gets a little routine. Sadly the age of the car will require some funds. I suppose that would be true of any model given 27 years. The benefit is the plethora of information. Its pretty easy to get up to speed on these vs when they were new. I encourage you to look at some of the faq sites and get back to us. Your current repair shouldn't be much. I'm basing that on past experience. We will need a little more info I think. Keep tinkering.
 

TSi-wesley

Probationary Member
15
1
Aug 16, 2019
Magnolia, Texas
Update: I just checked the MPI relay fuse and confirmed that it was okay. I just took off my ECU to find that it is EPROM ECU rebuilt by Motoguys garage which, coincidentally, is no longer in business, so I'm assuming I don't have a warranty on the ECU. But I did check the diagnostic pin by the driver side fuse box and got no signal from it when cycling the ignition. I contacted ECM Tuning and they suggested testing the MPI Relay before sending the ECU in to them. If the MPI Relay checks out then its more than likely a damaged ECU
 

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pauleyman

DSM Wiseman
6,559
1,733
Nov 19, 2011
oklahoma city, Oklahoma
Update: I just checked the MPI relay fuse and confirmed that it was okay. I just took off my ECU to find that it is EPROM ECU rebuilt by Motoguys garage which, coincidentally, is no longer in business, so I'm assuming I don't have a warranty on the ECU. But I did check the diagnostic pin by the driver side fuse box and got no signal from it when cycling the ignition. I contacted ECM Tuning and they suggested testing the MPI Relay before sending the ECU in to them. If the MPI Relay checks out then its more than likely a damaged ECU
You're on the right track. Shouldn't take much to narrow it down now
 

steve

DSM Wiseman
13,736
828
Feb 3, 2002
Boulder, Colorado
You can see all the corrosion that wasn't taken care of before. I wouldn't be surprised to discover that either the trace to the pin from the ignition switch or the trace to the pin to activate the MPI relay is no open due to the corrosion from the original capacitors leaking.

The guys at ECMTuning should be able to fix that all up but it should have never gotten out the door of Motoguys garage without cleaning that all up.
 
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