4g64/4g63t Hybrid

[~MoMo~]

Need some help with my hybrid setup here.
Searched the forum but couldn't find anyone with this issue.

Fully built 4g64 block with 4g63t head, I degreed the cams with adj. cam gears and all is well. So, perfect mechanical timing with a 4g64 galant timing belt and degreed cams. Static compression equals stock 4g63t numbers.

Soooo.. I have to run the car with the stock T25, stock ecu/fuel/injectors/pump (inspection reasons), but it will not pull very well at all. Feels like it's waaaay down on timing, so I'm thinking this stock turbo/ecu/fuel deal isn't working due to the increased displacement? It boosts well and I can't find anything mechanically wrong.
I replace the FPR and got a low-mileage set of stock injectors from a known-good car too.

Would this setup cause the ecu to ramp up the injector duty cycles (due to the increased air flow) and thus pull back a lot of timing?
I'm not sure what else it could be?

I bought this car half-built and had to finish up all the loose ends but I can't get it to run well with the stock setup. Do not have a logger either, should probably get one but which to buy?

Would really appreciate whatever help I can get here guys!

 

[DogWhistle]

Did you add the knock sensor from the 4G63?

 

[bryanwheat]

The turbo will run out of air faster with more displacement. Have you checked for boost leaks? A leak with a T25 will make the car a dog.

 

[~MoMo~]

Did you add the knock sensor from the 4G63?

That's an extremely good question. I don't know, I didn't build the longblock, but I know there's a knock sensor connected. Any way to tell which is which?

And yes, I've done several boost leak tests and found the TB shaft seals leaking a lot. Changed them out and no more leaks.

 

[DogWhistle]

The knock sensor on the 4G63 is located on the rear of the block, approximately between the #2 and #3 cylinders. You will have to trace the siring to know if it is truly connected to the ecu. Without a knock sensor, the ecu will limit your total timing to about 10 degrees, which will not take advantage of your full potential.

 

[~MoMo~]

Well the knock sensor is connected at least. I need to trace it to the ECU, anyone know which pin the ECU get the knock signal to?

 

[DogWhistle]

Your profile did not say what year your Eclipse is. What year is it? Are you using the original ecu, or has it been replaced? Each ecu has a model number on the sticker on top of the unit. That number will tell you which year and version you have.

 

[~MoMo~]

Yeah sorry, this is a '98 spyder gs-t. ECU and pretty much everything else is supposed to be stock, but I should probably verify this. It does idle and drive nice though, good low end torque but incredibly dead up top.

It's a pain taking over other peoples half-assed work not knowing what's been done and trying to sort things out as sh*t unfolds

 

[DogWhistle]

Agreed. It is almost impossible to understand why some motorheads do what they do -- from ignorance, or being cheap. Many nice dsms can be found for reasonable money because the current owner can't track down what's wrong.

Here is a link to dsmlink that has the ecu wiring pinouts labeled. This diagram is for the 2G 95-96 ecu with turbo. Yours may be different, but start with this to see if your pinouts match up.

The knock sensor is located on pin 78, on the 22-pin, B-56 connector, using a white wire.

http://www.dsmlink.com/images/forums/2GECUPinout.pdf

To fully track this problem down, you will have to individually verify that all the sensors are working within spec, such as the O2 sensor, and throttle position sensor, etc.

You can find the procedures for checking all of these in previous threads.

 

[Riceburning101]

Honestly the lack of power is probably the stock ecu and a t25. I have a 16g and it spools retarded fast. I cant imagine the t25 on a 2.4 setup. People complain about the power drop off with a 2.0 on the top end with a t25 so a 2.4 is going to reach that a lot faster than a 2.0.

 

[WES_393]

Honestly the lack of power is probably the stock ecu and a t25. I have a 16g and it spools retarded fast. I cant imagine the t25 on a 2.4 setup. People complain about the power drop off with a 2.0 on the top end with a t25 so a 2.4 is going to reach that a lot faster than a 2.0.

Agreed.

Your now moving nearly 25% more air per RPM. And the T-2-Small isn't exactly known for it's flow capabilities...

 

[~MoMo~]

Granted, the t25 probably isn't the best match for this engine, but is it that bad?

Would a 14b or 16G be a better match? Those are close to bolt-on right? A new O2 housing and fab some intercooler pipes and I'm all set? Probably new oil feed too.

So to get this running better with a 14b/16G I'd need

- New oil feed
- O2 housing
- Fab some intercooler pipes (I have a fmic, just need a J-pipe?)
- Bigger injectors (?)
- Fuel pump (?)
- Air/fuel controller (like a safc2?)

Do I need a new fuel pressure regulator as well?

Not looking for an all out performer nor break any records (or parts for that matter), just need this engine to be more optimized. Right now I can safely assume a stock 4g63t gst/gsx would run circles around me.

I've decided to get EvoScan for logging purposes, should make it a lot easier to track down faults and whatnot.

 

[bigdnno98]

You have a built 2.4. I wouldn't go any smaller than a 20g. Also you're going to need to put very large cams in it. The motor is prob choking for air. You most importantly need to log though. This should tell you what's going on.