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Dozer1160

Probationary Member
7
0
Sep 2, 2015
Duluth, Minnesota
I have a 98 eclipse that I recently acquired... has been hacked together to say the least LOL... I'm pretty sure its a non turbo engine that someone put a turbo on at some point... it is not currently on the car but in the back of the car there is a round chrome thing spliced into the fuel line... I have included a diagram of where the hoses go ... what is it and what does it do... would it make the car run rich/ idle bad??... the large hose on the bottom of it goes all the way to the intake and is plugged into the port where the pcv hose originally goes
 

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That is an FMU. basically its a fuel pressure regulator that increases fuel pressure based off of manifold pressure. They are non adjustable set ratios. By the looks of it, its a cheapo ebay brand one.

And yes you have a non-turbo 420A engine. If someone did put a turbo on it and used that FMU then it was most definitely hacked together. Cheap part and a Sub-par way of 'tuning'.
 
You do have a turbo charged 420a DSM motor.

What you have there would be a fuel pressure regulator or FMU made by JDM Sport:
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You do have a turbo charged 420a DSM motor.

What you have there would be a fuel pressure regulator or FMU made by JDM Sport:
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can I take it out??? if I do where does the small line on top of the gas tank go to??? and do I just plug the line feeding the fmu??
 
so if I read that right I need to buy a stock fpr? and where does it go?
 
If you are keeping it turbo'd, I would not switch to a stock fpr. I would buy an afpr and megasquirt it if is hasn't been already. Otherwise, you're going back to factory fuel levels with a turbocharger, which is a grenade in the making. You're saying it's not installed now? You need to determine how the car has been tuned. FMU's like this was how people added fuel for turbo's before megasquirt or sfmu's became available. The guy who turbo'd your car was either trying to do it cheap or did it a long time ago.

Start by determining how this thing is getting the right amount of fuel now (if it is). Do you have a wideband installed?
 
I'm guessing no cause idk what that is LOL never messed with these cars... I have muscle cars....
 
No worries. A wideband is an oxygen sensor that reads a wider range than a factory "narrow band" oxygen sensor. You use it with a gauge and/or logger to figure out how rich/lean you're running. A standard narrow band signal will only tell you that you're off, not not if you're off an inch or a mile so to speak. For turbocharging an N/A car, it should be one of the first things you buy, because it's critical to know when you are lean. Leaning out too much, and in some cases being wildly too rich, can cause knock/detination, which can be catastrophic for a turbocharged engine. Knock is when the fuel in the cylinder ignites at the wrong phase in it's cycle. If you had one, you'd most likely have an aftermarket gauge in the car for it.

Start reading in the 420a sections of the sites what it takes to turbo one of those cars. You need to do a checklist to see what your car has and doesn't have before you buy or change anything. You need to know everything about the fuel setup and you need to know if they have megasquirt (an aftermarket ecu that you can reprogram to change the fuel and timing maps).

From the sounds of everything, this thing is likely untuned, and very likely isn't getting the right amount of fuel when boost kicks in. I would want to know what fuel pump it has, what injectors it has, what aftermarket gauges and sensors are installed, what turbo it's running, and how much boost it's pushing. You'll need to know at least all of that to figure out how to get a handle on the car.
 
There is no turbo on the car anymore... it has a 4 wire o2 sensor wich I'm assuming is stock just relocated.... it injectors have no markings on them so I'm assuming they are stock as well... there is a digital air/fuel ratio gauge in the car also but it isn't hooked up either.... I was gonna hook it up but I'm unsure of what wire on the o2 sensor to connect it to.... I'm not trying to returbo the car just trying to get it running right... it surges at idle and sometimes dies but only when you come to a complete stop... pulled the plugs and they are full of black carbon..... I also tried to locate the ecm wich I was told was behind the radio and can't find that either...LOL
 
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Behind the radio, you'll see three big cable connectors with a ton of connections on them about 6 or 7 inches wide total. That's the ecu harness. Should be able to trace that to find it.

If there's no other FPR on there, that would explain why it's so rich. I would still go with an AFPR myself. Not much more money and you get a bit of flexibility. I got mine from the classifieds here really cheap. Pull the fuel pump to see if they put it back to stock. Most people turbo with a Walbro 255, which is too much for a stock regulator anyway. Trace the injector packs back and see if they put a resistor pack on them. A lot of people go with 450's off a turbo model for a cheap upgrade, but it requires adding the resistor pack since the impedance is different.
 
On 420a powered DSMs, the stock location for the ECU is in the engine bay in front of the drivers side strut tower. The fuse box is right there with the ECU sandwiched between the strut tower and the fuse box.

Unless someone relocated it.
 
It's got the stock ecu....but I scanned the codes finally and it comes up with a temp sensor code so I got a new one and when I went to put it in I noticed the wires were broke off at the plug so does it matter what wire goes where? It's a 2 wire plug....
 
It's got the stock ecu....but I scanned the codes finally and it comes up with a temp sensor code so I got a new one and when I went to put it in I noticed the wires were broke off at the plug so does it matter what wire goes where? It's a 2 wire plug....
Test to see which one is the hot wire to be positive. It shouldn't matter, but if gauge sensors need the specifics I am sure engine sensors do. Just my $.02
 
It's got the stock ecu....but I scanned the codes finally and it comes up with a temp sensor code so I got a new one and when I went to put it in I noticed the wires were broke off at the plug so does it matter what wire goes where? It's a 2 wire plug....

looking at the plug as it sits in the engine bay I believe black goes on the left and green on the right. That 2 wire sensor goes to the ECU and supplies actual temp numbers. the other single wire one is for the dummy gauge on the instrument cluster.
 
looking at the plug as it sits in the engine bay I believe black goes on the left and green on the right. That 2 wire sensor goes to the ECU and supplies actual temp numbers. the other single wire one is for the dummy gauge on the instrument cluster.
I have black and black with a brown stripe
 
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