ecu buying questions

[laser9320]

The cars a 93 laser 2 liter non-turbo manual transmission. I'm wanting to do a turbo conversion and I guess I need a turbo ecu. What should I look for in a used ecu? What questions should I ask about. What sensors/wires/harenesses will I need to get it to work? Will an ecu from an auto tranny work? What is an eprom ecu? What are the alternatives to buying a used ecu? As you can see i really have no idea what to get so any help is appreciated. thanks

 

[airkyd]

Well, I think that you need to get an ECU from your exact car to have everything running perfect. Now, I think the eprom chip is used for upgrading the ecu for performance. If you're looking for an ECU, call 800-546-2673. Good luck

 

[Boosted_TSi]

When looking for an ECU, the main thing to consider is which year turbo motor you are getting. the 1990 motor has a different wiring system than the 1991-1994, so you need to make sure that the ECU matches in that respect.

The next thing is what injectors the new motor uses. If it has 450cc injectors (engine is a 1G out of a M/T) then you need an ECU from a Manual transmission car. The automatic turbo cars were equipped with 390cc injectors, and their ECU's were programmed to deliver the right amount of fuel for those injectors. The manual trannied cars had the 450cc injectors, and their ECU's were programmed to make use of the extra flow.

Something that you should look out for when getting an ECU; there are three or four capacitors on the main board of the turbo ECU that are prone to leaking. This causes some VERY weird behavior. Thankfully, on www.vfaq.com there is a walkthrough on how to replace the capacitors. It is a good idea to change the capacitors, even if they don't look like they are going bad... YOU NEVER KNOW.

The Eprom chip is not something that you will most likely need to worry about. If your new ECU has an EPROM chip, that means that it can be "rewritten" to control your upgraded injectors, and a bunch of other little stuff. Check out www.TMO.com to learn more.

Questions to ask when looking for a new ECU:
1: What year is it from?
2: Is it from a Manual trannied car? or from an automatic?
3: Have the capacitors been replaced?
4: Is it an EPROM ECU? This should not be of great importance, and if you come across a good deal on a non-eprom ECU, by all means, get that one; you will at least have an ECU...

Hope this helps,
-Eric McCabe

 

[laser9320]

yes it helps alot thanks

What sort of moddifications does it take to make a 90 ecu work on a 91-94 wiring system? I found a ecu for $60 but its off a 90. If its more than $20 worth than I'll just find a 91-94 but I'm on a tight budget and any little bit helps

 

[ninja0331]

Any ECM from a 91-94 Non-Turbo will work on your car. Boosted_TSI gave a really good explanation but he forgot you have a NON-TURBO car. The injectors on your car are 240cc's whether it's automatic or manual.

The EPROM ECM is rare and therefore more expensive, you should get this one by all means if you plan on doing major mods to the motor. Don't get the turbo ecm because it has a different setup, not only in the fuel, but in many more parts.

The turbo car has a knock sensor, a blowoff pressure sensor, and 2 other sensors the non-turbo car lacks. Plus each ecm has a motor code that makes it behave differently depending on what motor it was applied.

One last thing, the california cars were equipped with more sensors for emmisions and if you put a california-ecm on a non-california car which lacks these sensors, the check-engine light might come on. I honestly haven't tried this, but on california cars if you so much as disconnect the egr, the check engine light comes on, so that's something to think about.

 

[Boosted_TSi]

The reason I did not mention anything about the Turbo- Non-turbo difference is that In the FIRST POST he said that he is swapping in a turbo motor, and he expressed that he understood that he would need a Turbo ECU to control it.
You do however bring up a good point about the California Emissions ECU. (not something that I worry about, because I don't live In CA. - but when buying an ECU from the internet, it is definately something to watch out for)
I believe the only difference between a 91-94 and a 1990 ECU is that two wires are in a different location. That means that you would have to remove the two wires from the ECU harness, and move them to another location in the harness. I believe there is also a VFAQ on this...

If you plan on modding the car to the point that you need the TMO mods, you would probably be better served with a standalone computer, such as the new AEM unit, or the proven performance of the Haltech.

-Eric McCabe

 

[ninja0331]

oopz!