Engine to ecu

[muddfisher85]

So I bought this 95 gst and was told it had a 99 gsx engine in it that was not running. I went on this site and looked up my ecu and the spare that came with the car Eclipse Talon Laser Galant 3000GT Stealth ECU ID Reference One of them model # E2T61683 which is out of a gsx made between 7/96-5/97. The other model # E2T61676 is out of a gsx made between 7/95-6/96. Now I can get the engine to idle rough and the air fuel ratio reads rich with the 61683, but when I put the 61676 in it will not start but the air fuel ratio reads lean. How can I figure out which ecu I need or can I just get one programmed for my car somewhere? And how can i tell what engine I really have?

 

[delta448]

First you need to determine if you have a 95-96 or either a 1G or 97+ Cam Angle Sensor. The numbers on the ECU cases aren't always reliable, boards can be swapped into different cases fairly easily.

If the boards are known to go with the cases, then you probably at least don't have a stock head. The 95-96 had the sensor on the opposite side of the head and it outputs an inverted signal to the other years. So, if an ECU from a 97 model year starts the car and the one from the 96 model year doesn't that would be the first thing I'd check.

If you have a 6 bolt swap, then you will have no crank sensor and will also have a 1G CAS, since the 6 bolt doesn't have provisions for a crank sensor and the 1G CAS must be rigged to output both of the necessary signals for the 2G ECU. If you have a 6 bolt swap then a stock 96 ECU will probably not run the car correctly since it will have trouble determining the actual cam position.

If you're running really rich at idle either the engine isn't warm, or you probably will find that the O2 sensor is bad, there's an exhaust leak before the O2 sensor, you have larger than stock injectors or you have really bad FPR overrun.

 

[muddfisher85]

So even with the 97 board in it it will not start all the time it will just putter then back fire for a while before it ever thinks of starting. And most of the time I end up unplugging the board and trying the other one unsuccessfully, but when I switch back to the 97 board it starts and it wants to die if you give it gas fast but if you give it gas slow it with rev up and show boost. What do you mean I dont have a stock head? And which sensor are you talking about is on a differnet side? But why a 97 board if I have a 99 gsx engine?

 

[delta448]

when I switch back to the 97 board it starts and it wants to die if you give it gas fast but if you give it gas slow it with rev up and show boost.

It sounds like you may have aftermarket injectors or really high fuel pressure. Especially if the throttle tip-in enrichment causes so much fuel to be delivered that it bogs and dies.

What do you mean I dont have a stock head?

I just meant that the head probably isn't the original one from the 96 engine.

And which sensor are you talking about is on a differnet side?

The Cam Angle Sensor. It attaches to the intake camshaft. The differences are that on a 95-96 engine the CAS is located behind the cam timing sprocket on the intake cam, whereas all 1Gs and 1997+ 4G63s have the CAS located on the transmission end of the intake camshaft. So, 95-96 engines produce a CAS signal that is inverted when compared to all other year DSMs.

But why a 97 board if I have a 99 gsx engine?

Any 97-99 turbo DSM ECU will run any 97-99 4G63T DSM engine.

 

[muddfisher85]

Does A larger fuel pump make more noise then a stock one? I do notice that when the car is running I can hear the fuel pump running like a steady humming noise. Now it might just be cause I have the back seat pulled out at the moment. How can I tell if I have larger fuel injectors or have a bigger fuel pump? And if so how would the stock ecu handle it? Could it? Does the maf sensor matter what year its from the car came with an extra one of those too. I tried them both didnt seem to matter which one was hooked up still ran rich

 

[delta448]

Does A larger fuel pump make more noise then a stock one?

Yes. Except for possibly the Supra pump.

How can I tell if I have larger fuel injectors or have a bigger fuel pump?

The easiest way to identify injectors is just to check the part numbers on the injectors using google. The fuel pump might be even easier since there are only a handful of different pumps it could be.

And if so how would the stock ecu handle it? Could it?

The stock 96-98 ECUs can't handle larger injectors without a piggyback fuel controller like an SAFC or MAFT to alter fuel delivery. A modified 1995 Eprom ECU, a black plastic cased reflashable 1998.5-1999 ECU or a rewired Evo 8/9 ECU can handle anything you throw at it with the correctly modified code.

 

[muddfisher85]

what if its stock injectors and bigger fuel pump can the ecu handle that? Sounds like i need a safc!

 

[delta448]

If the pump is larger than a 190lph, you will probably just need to install an aftermarket Adjustable Fuel Pressure Regulator (AFPR). From what I've heard many tuners have reported not needing one with less than 190lph of pump flow.

The actual problem is that the stock FPR is unable to bypass enough fuel back to the tank, so it becomes overrun, fuel pressure rises and the car runs richer and richer.

More specifically, you need to get an AFPR that raises pressure on a 1:1 ratio when referencing boost and also can bypass the larger volume of fuel needed to keep fuel pressure from rising when the engine is operating with a low Injector Pulse Width (IPW), such as with warm idle in warm weather. Aeromotive and Fuel Lab make some nice AFPRs.

 

[muddfisher85]

Will this one work it came off a first gen eclipse but its a good price? Aeromotive Fuel Pressure Regulator : eBay Motors (item 140382525197 end time Feb-17-10 13:30:32 PST)

 

[delta448]

If it is indeed the 13301, then it should be fine as long as you use the high pressure spring as mentioned in this link.

Aeromotive|Universal Bypass Regulator

 

[muddfisher85]

It says that I will have to install the Bypass line to the top of th tank is that right and if so how I have never really messed with fuel lines other then swapping a fuel pump. You do run it under the car right? And will the kit come with the hose or will I have to buy that too? Does this one come with a pressure gauge or do you not need to know what it is it just regulates it on its own I thought it was adjustable.
Thanks so much for your help

 

[delta448]

You only need to connect it to the stock fuel return line. The stock FPR is on the driver's side of the fuel rail and the return line is attached to it.

You may need some fittings and line to install the AFPR, and you'll also need to buy a pressure gauge in order to set base pressure. Many vendors offer solutions for this, but you'll have to double check which fittings are included versus which ones you need for your specific AFPR. Here's an example.

I think if it were me, I'd just try to buy a new regulator and maybe one a little more robust. Something like this kit.

Have you verified that you actually need the AFPR? You might not need one if you have a stock or even a 190lph pump.

 

[muddfisher85]

Have you verified that you actually need the AFPR? You might not need one if you have a stock or even a 190lph pump.[/QUOTE]

I have yet to verify yet I will try to get to it tomorrow. To bad you dont live a little closer Id just pay you to help me figure out what I have and whats going on with it. There is not any tuner shops around that I know of and have yet to meet any local tuners who are willing to help me out. Ill post more after I check everything out. How can you tell if you need a new ecu any test other then just hooking it up?

 

[delta448]

You can open it up and check the board for any leaking capacitors or damaged traces. There would probably be a fishy smell and the appearance of the caps would be pretty obvious if they were leaking badly enough. From my understanding this is more of a 1G ECU issue though.

Still wouldn't hurt to verify which boards you have in those cases.

I'm really surprised nobody else is posting in your thread.

 

[muddfisher85]

Does it say on the board which one it is I opened them up and they look the same and nothing looks burnt and didnt smell funny. I am surprised that knowone else has posted either

 

[delta448]

Look at the number printed on the top of the wiring harness connector and see if it matches the last 4 digits of the E2T number on the case's sticker. If they match then the board belongs to the case.

 

[jeffo]

As Delta448 said way back, you really need to also make sure what Cam Sensor you are running. Did the guy take the 99 motor complete, and drop it in your 1995? If so, how did he handle the difference in the Cam Sensor position and wiring? That E2T61683 1997 ECU should run the car perfectly, if you have stock injectors. Don't go off buying parts until you get us more information to go on.

 

[delta448]

I agree.
I think that the injectors will probably be identified as being 550-650cc or maybe even slightly larger.

The guy you bought it from probably pulled out his stock Eprom ECU and/or SAFC before selling. Was the car running when you got it?

My opinion right now is that the 96 ECU won't start it because of the wrong CAS signal and the 97 is flooding the engine. That's why the 97 starts it after the 96 has cranked it a few times, the 96 ECU is allowing some of the excess fuel to get pushed out into the exhaust.

 

[muddfisher85]

The Cam Angle Sensor. It attaches to the intake camshaft. The differences are that on a 95-96 engine the CAS is located behind the cam timing sprocket on the intake cam, whereas all 1Gs and 1997+ 4G63s have the CAS located on the transmission end of the intake camshaft. So, 95-96 engines produce a CAS signal that is inverted when compared to all other year DSMs.

So my CAS is located on the transmission side of the intake cam and the wiring doesnt seem to have been switched or anything.

And to Jeffo's question the told me he took the whole engine as far as wiring im not sure. The car was not running when I bought it. It needed a starter the guy said and it would run great I knew that was a joke for 1000 bucks it has a good bit done to it full trust exhaust, hks turbo timer, stage 2 clutch, lightened flywheel, aftermarket side mount intercooler and intake hard piping and forge blow off valve, boost and air fuel gauge. So i replaced the starter and here is where im at. My best guess is the car was never running. So what do you think he used the 95 harness and never switched those wires? Any way to tell?

 

[delta448]

I think you need to ditch the 96 ECU for now and stick with getting the 97 ECU to run the car correctly. I imagine that the previous owner had either not started the vehicle after the swap, or had a modified ECU he removed and just threw these two ECUs at you in case you complained.

 

[muddfisher85]

So which wires should I switch do you think it has 95 wiring?

 

[delta448]

I don't know for sure about any wiring differences, but I don't think it matters as long as the ECU is getting all the necessary signals to start the car. Does the CAS not have a harness plug attached?

 

[muddfisher85]

no it does but I thought it might be sending a inverted signal if the wires were from a 95

 

[delta448]

I think you may have misunderstood something or maybe I was unclear on what I meant, it's the CAS sensor that is different. It's signal is inverted compared to the others, it's not as simple as switching wires. I can't seem to find it now, but I remember seeing a drawing that compared the two different signal types as viewed with an oscilloscope. I can't swear by this info but, IIRC, it looked something like this:

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The trigger being represented by the bump from the reference voltage.


I think the next step in fixing your problems is to find out exactly what size injectors you have.

 

[muddfisher85]

I understand now. So check the injectors and fuel pump are next on my list