420a obd1 to obd 2 conversion

[Psawangj90]

I need an ecu for my 1995 eclipse with a 420a. I have went to every junkyard nearby and only found one from a 95 talon since its the same thing. I bought it and as my luck would have it, its not telling the injectors to spray. My dads friend who is a mechanic sprayed starting fluid in the intake and the car started but wouldn't stay running. He said the ecu is no good. So i was wondering what it would take to swap over to a newer ecu that runs obd2. Is there anything different than the wiring harness? And how far back do i need to change the wires? Any help would be much appreciated. There's many 2g manual 420a eclipses that i can get all this for maybe 60 bucks which is a lot cheaper than buying from a parts store. Im willing to spend my free time doing this work so i can get my car back!

 

[synthetek]

All 2gs are OBDII

 

[Broke4speed]

If someone sprayed starting fluid into an OBD2 car, they are the worst mechanic in the universe. Never let them touch your car again.

If it fired up and ran, then it's not the ecu. The spark is CONTROLLED BY THE ECU. Did he scan it to see if there were codes? Did he try jumping the fuel pump/MFI relay? Did he do anything but try to diagnose it as if it were an old tractor?!

Find a better mechanic.

 

[cliffkemp]

Howell auto may have one. check out there site and see, if you want. As stated before too, all 420a motors come with OBD2 cpus. There are several places to find one if you look.

 

[1G Eclipse94928]

Sounds like you need a new mechanic based on title and post.

 

[Broke4speed]

The first thing a mechanic unfamilar with post - 1980's technology will say is "the ecu is bad".

I'm still floored by this.

 

[silvreclips]

If someone sprayed starting fluid into an OBD2 car, they are the worst mechanic in the universe.

There is nothing wrong with this.

 

[DJ Raydiate]

OP , have you tried to get any codes out of the ECU? The computer should guide you to letting you know what's going on. If you don't have a scanner, you're lucky enough to be able to do the key dance and count the cel flashes to get the codes. I would honestly start there.

 

[Broke4speed]

There is nothing wrong with this.

Not physically, but it points to HUGE gaps in their knowledge/ability to diagnose problems. An EFI'd car will not fire up unless the ECU is in control. Starting fluid is great for getting an engine to run when the carb is not set up, or iced over. Getting the engine running will force the carb to function, and a points-based distributor doesn't have an ecu, so it will fire if it spins.

1) DSMs don't have carbs.
2) DSMs don't have points-based distributors.

See where I'm going with this?

Prior to drowning it in ghetto fluid, they should check for spark and fuel, and then pull the codes from the ecu. If the scanner communicates with the ECU...it's not dead. If there's a problem with the ecu, the scanner will point that out.

Always use the right tool for the job.

 

[DJ Raydiate]

Not physically, but it points to HUGE gaps in their knowledge/ability to diagnose problems. An EFI'd car will not fire up unless the ECU is in control. Starting fluid is great for getting an engine to run when the carb is not set up, or iced over. Getting the engine running will force the carb to function, and a points-based distributor doesn't have an ecu, so it will fire if it spins.

1) DSMs don't have carbs.
2) DSMs don't have points-based distributors.

See where I'm going with this?

Prior to drowning it in ghetto fluid, they should check for spark and fuel, and then pull the codes from the ecu. If the scanner communicates with the ECU...it's not dead. If there's a problem with the ecu, the scanner will point that out.

Always use the right tool for the job.

While this is a good statement, I would have to disagree with some of this.

"Ghetto fluid" as you call it, could be a very useful tool even in todays technically advanced vehicles.

While I would agree the getting codes is the way to go, it is not always available. For example: if someone does not own a scanner and the car will not run for them to take it somewhere to get the codes read. That is why I said that the OP is lucky enough to do the key dance to be able to get the codes. Another example is if the ECU is not communicating with the OBD2 port. I got my car dirt cheap because the PO thought the ECU was bad because no shop could read the ECU through the port to pass it for inspection. I had to replace some fuses in order for it to be able to be scanned.

The same statement about checking for fuel and spark first is still true for carbed vehicles. Just because it has a carb and the very early ones have points, doesn't make it any less of and engine. It still needs the triangle to be able to run. Not all carbed vehicles have points.

 

[1G Eclipse94928]

While this is a good statement, I would have to disagree with some of this.

"Ghetto fluid" as you call it, could be a very useful tool even in todays technically advanced vehicles.

While I would agree the getting codes is the way to go, it is not always available. For example: if someone does not own a scanner and the car will not run for them to take it somewhere to get the codes read. That is why I said that the OP is lucky enough to do the key dance to be able to get the codes. Another example is if the ECU is not communicating with the OBD2 port. I got my car dirt cheap because the PO thought the ECU was bad because no shop could read the ECU through the port to pass it for inspection. I had to replace some fuses in order for it to be able to be scanned.

The same statement about checking for fuel and spark first is still true for carbed vehicles. Just because it has a carb and the very early ones have points, doesn't make it any less of and engine. It still needs the triangle to be able to run. Not all carbed vehicles have points.

I think the point is imo it sounds like a fuel problem and the guy just decided the computer is broken cause it cant unclog injectors or redo your fuel system for you. If the car starts after injecting a fuel supply into it, the ecu is giving the car spark, but the car isn't getting gas. So its pretty obvious its a fuel system issue, or something electrical... Not the ecu. People who claim to be mechanics but don't really spend time to diagnose anything are the worst, and must like to burn your money.

 

[DJ Raydiate]

^ This. I too think it's a fuel problem. No mention of fuel pump whine, or the last time it had a tune up. It could be as simple as a relay and or fuse. There does need to be someone else there to diagnose the car but the fact that it ran with the starting fluid as a tool, is a good sign. I was just trying to agree with silvreclips that there is nothing wrong with using starting fluid and that not everyone has the opportunity to have the codes read.

 

[pauleyman]

Why couldnt it be ecu? Its obvious fuel is the issue and ecu could be one possibility. Not necessarily most likely but a very real possibility. Dont be so quick to say it is or is not something. You do not have all the facts. What you have is assumption.

 

[AK Maniak]

Not physically, but it points to HUGE gaps in their knowledge/ability to diagnose problems. An EFI'd car will not fire up unless the ECU is in control. Starting fluid is great for getting an engine to run when the carb is not set up, or iced over. Getting the engine running will force the carb to function, and a points-based distributor doesn't have an ecu, so it will fire if it spins.

1) DSMs don't have carbs.
2) DSMs don't have points-based distributors.

See where I'm going with this?

Prior to drowning it in ghetto fluid, they should check for spark and fuel, and then pull the codes from the ecu. If the scanner communicates with the ECU...it's not dead. If there's a problem with the ecu, the scanner will point that out.

Always use the right tool for the job.

While I'm not saying everyone should go out and do this you can use "ghetto fluid" to check for boost leaks.

 

[jayson427]

I bought my ecu through a junk yard finder online it's easy to Google. I got it within a week and it had a warranty. Take the fuel rail out with the injectors intact and try to start the car to see if it sprays fuel really quick. It's not the best method but it works. Then go from there.

It would take way to much work to swap to obd2 then it would be to just fix your issue.

 

[pauleyman]

I bought my ecu through a junk yard finder online it's easy to Google. I got it within a week and it had a warranty. Take the fuel rail out with the injectors intact and try to start the car to see if it sprays fuel really quick. It's not the best method but it works. Then go from there.#

You dont even have to do this. You can listen tothe injectors with a mechanics stethoscope or screwdriver and see if its being activated. If you want to check fuel flow look at fuel return and/or listen for fuel pump.

 

[jayson427]

You dont even have to do this. You can listen tothe injectors with a mechanics stethoscope or screwdriver and see if its being activated. If you want to check fuel flow look at fuel return and/or listen for fuel pump.

Like I said not the best method but for someone that's not sure how to do a compression test I'm sure what I suggested is the easiest way, it's only 2 bolts. And just because the pump turns on doesn't mean the injectors are pulsating.

 

[pauleyman]

Did you even read what I wrote?

 

[electrohead]

All 2gs are OBDII

On 420a powered cars, '95 was the only year they were OBD1. That's why I have to do the sniffer test every year for emissions, no diagnostic port. It also was the only year they tried a secondary air valve for emissions (which didn't work). And it was the only year that did not have a returnless fuel system. It doesn't make sense why they didn't just go OBD2 from the start, but it's just the way it is.

 

[1G Eclipse94928]

You dont even have to do this. You can listen tothe injectors with a mechanics stethoscope or screwdriver and see if its being activated. If you want to check fuel flow look at fuel return and/or listen for fuel pump.

I've never had injector problems so i'm not an expert but if there clogged could you still be hearing them pulse but there clogged so no fuel is getting in there? Would be my only reason why his was would be more definite, if i'm wrong invest in a mechanical stethoscope, there very useful!

 

[electrohead]

You might want to try wiggling the wires in the ECU harness. The wires are really crammed in there. I had a problem with my car dying in traffic and not wanting to turn over after it warmed up. I thought it was the ECU, so I replaced it and the problem was still there. I trier wiggling the wires just for laughs and car fired right up. Never had a problem since. Just some food for thought.

 

[1G Eclipse94928]

You might want to try wiggling the wires in the ECU harness. The wires are really crammed in there. I had a problem with my car dying in traffic and not wanting to turn over after it warmed up. I thought it was the ECU, so I replaced it and the problem was still there. I trier wiggling the wires just for laughs and car fired right up. Never had a problem since. Just some food for thought.

woh, thats bad, I would assume one of your wires is partially broken. worst place for a broken wire is hidden back in the dash.

 

[synthetek]

On 420a powered cars, '95 was the only year they were OBD1. That's why I have to do the sniffer test every year for emissions, no diagnostic port. It also was the only year they tried a secondary air valve for emissions (which didn't work). And it was the only year that did not have a returnless fuel system. It doesn't make sense why they didn't just go OBD2 from the start, but it's just the way it is.

You have to do the sniffer test because OBDII wasn't required on cars until 1996. DSMs had OBDII in 95 before it was required but cars before 96 don't have to do the OBDII emissions test. DSMs were some of the 1st cars to have OBDII

OBDII: Past, Present & Future

 

[DJ Raydiate]

+ 1. My parts car was a 95 and it had obd2. Just fyi.

 

[Broke4speed]

While this is a good statement, I would have to disagree with some of this.

"Ghetto fluid" as you call it, could be a very useful tool even in todays technically advanced vehicles.

While I would agree the getting codes is the way to go, it is not always available. For example: if someone does not own a scanner and the car will not run for them to take it somewhere to get the codes read. That is why I said that the OP is lucky enough to do the key dance to be able to get the codes. Another example is if the ECU is not communicating with the OBD2 port. I got my car dirt cheap because the PO thought the ECU was bad because no shop could read the ECU through the port to pass it for inspection. I had to replace some fuses in order for it to be able to be scanned.

The same statement about checking for fuel and spark first is still true for carbed vehicles. Just because it has a carb and the very early ones have points, doesn't make it any less of and engine. It still needs the triangle to be able to run. Not all carbed vehicles have points.

I've been working with EFI cars for 20+ years, and while I don't doubt the usefulness of ghetto fluid...I've never had to use it. I'm self-taught too, so if a trained 'mechanic' doesn't have a scanner to check codes, then he's not a technician. I have one, and it was $15. For this mechanic to spray it, then diagnose it as a dead ecu is pretty dumb, IMO. He didn't even do half the work he should have in order to come to that conclusion.

The right tool for the job.