wrong ECU?

[Deadly BlaZe]

i have a question for all of you. my car has been running very slow. i just drove my friend's mx-6 and that thing was faster than mine STOCK. so i call up my dad and ask him what's wrong with my car because it doesnt accelerate at all. he tells me that the ECU in the car is not the original one, it's from another talon. he's also telling me that the ECU for the car has to be very specific and that even an ECU from a different talon (even though the ECU it self is functioning perfectly) can mess up the performance of a different talon. is what he's saying true? i would think that an ECU from any 1g talon would be identical.

 

[Quasimondo]

There's a few possiblities I can think of.

You have an ecu from a n/t dsm. Not sure if your car would even run with one in there, but it's possible.

You have an ecu from an a/t dsm. That ecu is tuned for a smaller turbo and smaller camshafts.

Have you checked everything else on the car and eliminated all other possiblities for why your car is running sluggish, such as boost/vacum leaks, proper tune up, replacement of all filters, etc?

Swapping ecu's just seems like an extreme step, and I'd hate to see you waste a good $200 only to find that the ecu wasn't your problem.

 

[Deadly BlaZe]

well, i've recently had a tune up done and i KNOW there is a problem with the turbo. but even with a semi-functional turbo the car should accelerate faster than it does now. my dad also tried 4 other ECUs and they all had problems with them and he said the one i have currently was the best choice but he says he's almost positive its the ECU. he said it has to be very specific.

 

[Quasimondo]

If there's a problem with the turbo, then you need to replace that first. The difference between running with a good turbo and running with a bad turbo is night and day. Is that turbo spooling up properly?

 

[Deadly BlaZe]

i really dont know if it's spooling properly, i've never driven a turbo before..infact this is my first car and i learned to drive a standard with it. how do you tell though if its spooling right?

 

[Quasimondo]

Max boost of 9-11 psi should be reached by 3000 rpm. You can check by doing a 3rd gear pull. At 2000 rpm in 3rd gear, floor it, it should start buiding boost by 2500 and max at 3000.

If you don't have a mechanical boost gauge, you need one. The stock boost gauge is inaccurate and useless as it doesn't give you a real boost reading, just an estimated one based on various sensor inputs.

 

[Deadly BlaZe]

so if its producing 9-11 psi the turbo is functioning fine? and does it have to be a mechanical boost controller or can it be an electronic one. and also, im not really sure about the answer to this, but when you floor it in 3rd gear at 2000 rpms is the acceleration supposed to be significant or barely go. because mine barely moves.

 

[Quasimondo]

Electronic or manual gauge is fine, as long as it's not the factory one in your dashboard.

When you floor it in 3rd at 2K, it'll start off sluggish, by 2500, it should start building, by 3000 it should be at full boost. I suggested 3rd gear bacause it's a high enough gear that you can actually check to see if your turbo is working properly or not.

 

[Deadly BlaZe]

alrite thanks for the advice

 

[oldman]

Electronic or manual gauge is fine, as long as it's not the factory one in your dashboard.

Only if "digital" is what he meant by electronic. The stock one is considered a electronic gauge because it does not measure boost pressure directly from a boost source like a mechanical one does. I don't like digital ones because I like to know how I get there as well as where, kinda like a tach. Tell us the MD#on the ecu in your car so we can tell you if you have the correct one. Your dad is wrong, the correct ecu should not affect performance in another car. Like Quasimondo said your problem is probably the turbo. Tell us why you think your car is slow, examples in detail. If we all try to boost at 2k, we would all be slow.

 

[Deadly BlaZe]

Only if "digital" is what he meant by electronic. The stock one is considered a electronic gauge because it does not measure boost pressure directly from a boost source like a mechanical one does. I don't like digital ones because I like to know how I get there as well as where, kinda like a tach. Tell us the MD#on the ecu in your car so we can tell you if you have the correct one. Your dad is wrong, the correct ecu should not affect performance in another car. Like Quasimondo said your problem is probably the turbo. Tell us why you think your car is slow, examples in detail. If we all try to boost at 2k, we would all be slow.

i mainly think my car is slow because i drove my friend's stock mx-6 and it was faster than my car. he drove my car and said it was slow as ####. when your in first gear revving up to lets say 4000rpm and when you floor it when going into 2nd gear, the car doesnt push its self forward, it barely speeds up. my friend who drives the mx-6 says that even with a f'd up turbo, the car shouldnt be this slow. my dad says he's almost 100% sure that its the ecu thats causing the problem. but im so confused now with what the problem could be. these are the things that my friend suggested is wrong with the car: either the clutch is bad which affects acceleration , maybe the turbo, or the ECU. oh and with the whole digital/electronic thing, i was thinking of boost controller at the time for some reason, not boost guage.

 

[Quasimondo]

Time for a bit of process of elimination here:

1. Clutch. Clutches are like on/off switches. Either they work, or they don't. If your clutch was bad, you'd have a horrible smoking smell which lasts for a few days followed by a car that doesn't move at all because the clutch would be fried.

2. ECU. Like said, it's only a bad ecu if you got one that was pulled from a non-turbo 2.0 engine or from an engine with an automatic transmission. Give us the part number on the ecu (should be MD*****) and we'll check to see what kind of ecu it's for.

3. Turbo. Most likely situation. Either the turbo is blown or you're dealing with problems that are affecting the turbo's performance. When you have an engine with a low compression ratio like ours,which is 7.8:1 (most natrually aspirated cars have compression ratios of ~8.5:1), if the turbo is not running right, it will feel dog slow.

Another possiblity is that the wastegate arm might have popped off of the flapper on the turbo.

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The silver can on the left is the wastegate actuator. The rod coming out of it is the wastegate arm. The thing it attaches to is the flapper door. When your engine hits 11 psi, a pressure signal is sent to the wastegat actuator, pushing out the arm and opening up the flapper door, slowing down the turbo and regulating boost. If that wastegate arm is not attached to the flapper door, as soon as you give it any gas, instead of spinning the turbo it's bypassing it and going straight out your exhaust and you'll get no boost.

 

[Deadly BlaZe]

thanks, im gonna get all this checked and ill try to get that number from the ecu

 

[Deadly BlaZe]

well i think i figured out the problem. that diagram above helped alot. i noticed that the flapper door does not open at all but the wastegate arm is attached to it. i would assume that this is the problem but whats causing it? also, the actuator looks like its been bent pretty weird but yea, is it the turbo that's causing this or what?

 

[Quasimondo]

Get an air compresssor. Hook the hose up to the wastegate actuator and pressurize it to 15 psi. It should force the arm to move. If it doesn't then the wastegate may be keeping the flapper open.

Pull the arm off of the flapper door, and make sure it swings open and shut freely. When you reattach the arm to the flapper, make sure that it cloes the flapper all the way and doesn't leave it open.

If those check out, then you may be dealing with a cracked turbocharger exhaust housing. 1G exhaust parts are notorious for cracking after years of extreme heat. When I pulled my turbo off, there was a 2mm gap around the flapper that even when it was closed, it caused enough of a leak to slow up my spool and I wouldn't hit full boost until 4000 rpm.

 

[Deadly BlaZe]

well, i did the air compressor test. the arm only moves half way, not all the way. but the flapper does swing freely when you take off the arm (or so my dad says, but that was a few months ago). also there's no air pressure going through a vacuum hose. oh and the housing isnt cracked.

 

[Quasimondo]

Did you ever get the part number of the ECU that's sitting inside of your car?

 

[Deadly BlaZe]

Did you ever get the part number of the ECU that's sitting inside of your car?

no i didnt because i just assumed that the turbo was what was causing the car to be so slow.

 

[steve]

Also there's no air pressure going through a vacuum hose. oh and the housing isnt cracked.

The hose to the wastegate actuator is connected to the outlet of the turbo compressor so that there is pressure in that hose when the car is boosting. Once the pressure in the hose exceeds the spring force in the WGA the wastegate arm moves and opens the wastegate.

I keep a ECU list on my site that shows what ECU originally went with what car. You can check your numbers against that.

Steve

 

[monotalonawd]

I keep a ECU list on my site that shows what ECU originally went with what car.

Steve, I see on your site that an ecu from a Federal manual 1g non-turbo 2.0l and from an automatic have the same part number (MD166255 E2T36572).

So they're interchangeable? I want to be sure 'cause I'm about to buy the ecu from a manual 93 Laser to put in an automatic 93 Talon. The two are non-turbo. Thanks!

 

[steve]

Steve, I see on your site that an ecu from a Federal manual 1g non-turbo 2.0l and from an automatic have the same part number (MD166255 E2T36572).

So they're interchangeable? I want to be sure 'cause I'm about to buy the ecu from a manual 93 Laser to put in an automatic 93 Talon. The two are non-turbo. Thanks!

The core data in the list is from Mitsubishi's CAPS program. It claims that the same ECU is used by both NA Federal MT and ATX Cars. Mitsubishi gives ECU's different part numbers if something a minor as a config resistor is different, so I'd bet the MD166255 works in either car.

Steve

 

[monotalonawd]

Thanks for the fast reply, Steve!

 

[i1nk83]

to the original poster you might want to check you timing as well. it could be to far retarded to provide you with power.