Weak 7MGTE

[IRONMAN]

I just got my GTE running and it idles smooth (too high but smooth), and runs smooth. However, when ever I get into boost it starts leaning out bad.
It pulls strong but then it start to gets weak when the turbo start spooling. I haven't been able to figure it out.

Mods:
Intercooler kit
3 inch exhaust
Walboro 255lph
Aeromotive AFPR (42psi)
Lexus AFM
Aftermarket OEM Replacement turbo with adjustable wastegate
New Knock Sensors and rewire (Can't get code 52 to go away)

It acts fine until it's boosts where it starts to feel like it is leaning out. (and by no means just a little bit)

 

[Poodles]

lexus AFM without the 550cc injectors...

 

[suprarx7nut]

Code 52 will cause issues until you clear that as well

Sent from my Galaxy Nexus using Tapatalk 2

 

[IRONMAN]

I have done a complete rewire on the knock sensors with 100% shielded cable and added new knock sensors. I adjusted the fuel pressure and it help a ton but it is still lean.
The AFM is cause the lean issure now but was not causing it to be as bad as it was. I adjusted the pressure from 36 to 24.

 

[IndigoMKII]

Fix your code 52. Add 550cc injectors with the lex afm. Keep pushing the engine like this and you'll soon be posting a thread about why the 7m is such a bad engine because you already have rodknock.

 

[MadRPM]

Also, you didnt mention any form of engine management. Do you have any engine management?

 

[IRONMAN]

No engine management. The AFM is it now. The code 52 never changes the way it drives and won't go away. No no I will not be posting that thread because as long as I open the waste gate not to boost it doesn't run lean. So under normal conditions I'm fine to drive it. A/F only goes lean at about 3 or 4 pounds of boost. No Boost no lean.

 

[Poodles]

I have done a complete rewire on the knock sensors with 100% shielded cable and added new knock sensors. I adjusted the fuel pressure and it help a ton but it is still lean.
The AFM is cause the lean issure now but was not causing it to be as bad as it was. I adjusted the pressure from 36 to 24.

Are you using a wideband to see the lean spot? Also, if you do a rewire, you have to ground the shielding.

Fuel pressure for the lexus AFM isn't nearly high enough, and it's not recommended (some people do get away with it, but I would never do it). Injectors are cheaper than an engine rebuild to me...

 

[IRONMAN]

I actually have replaced the fuel pump (Walbro 255lph) then retuned the pressure and it helped a lot. However I need to ground the shielding and I'm waiting on injector money.
No I'm not using a wideband I have equipment just good enough to tell it is going lean. but it doesn't even really leave the range of my little meter I have.
It only runs lean over about 3-4 pounds anyway. I opened up the wastegate so no boost, no lean. ( This is just temporary of course.)

 

[Poodles]

I still don't get how you know it's lean without a wideband...

 

[MarkIII4Me]

In for the ::bhg::

 

[suprarx7nut]

I feel a face palm moment coming up in this thread.

Sent from my Galaxy Nexus using Tapatalk 2

 

[Supraguy7M]

I second that..^... more air (about 25% more air with the lex afm) with stock fuel injectors.... lean conditions makes the combustion chamber gasses hotter... gunna end up with a bhg sooner or later, seeing as the back 2 cyl run hotter anyways... or worse.. id put the factory afm back in, and run the car that way. then when you have money for the injectors, then its safe to do the lex/550 mod..

 

[Another MkIII]

Code 52, no wideband, stock injectors with a Lexus AFM, no enginemanagement and you want to know what's wrong with your car? I think the problem is somwhere between the seat and the steering wheel.
-AM3

 

[gsxr141]

add 550's then get back to us.

 

[IRONMAN]

A regular gauge on the stock O2 until I get a better one. If it runs lean it will read lean no matter how far the gauge reads.
On this gauge it just reads all the way leaned out when I get out of range. In which case I don't care how lean it is, there is obviously a problem.

On another note The Knock sensor also makes it runs richer. Not only that but if I am only running leaner in boost the obvious answer is to not boost.

Third, My factory is bad and the car only idles with it in. Another obvious answer, keep the part that works. Now I know that when I replaced the fuel
pump and dropped the pressure it evened out the A/F ratio a lot (except in low rpm's where it is really rich), not only that but with both new knock sensors and a rewire with grounded shielding I still get a knock code.

So I'm trying to find:
Why the Knock code still exists
and
why it runs lean under boost (which is the AFM)(Will replace injectors soon)

The knock code retarding the timing and making it run too rich down low is what I am concerned with.

 

[ForcedTorque]

Did you check for continuity from the ECU plug to the knock sensor plug AFTER the repair? BTW...I did that repair myself today. If you did, how did you get your test lead into the harness connector?

 

[jetjock]

I feel a face palm moment coming up in this thread.

Well done, Kemosabe...

 

[ForcedTorque]

If you are on a limited budget, your cheapest option is to replace the AFM with a used stock one. Then retrace every step that YOU have done, and find the mistake.

 

[Poodles]

A regular gauge on the stock O2 until I get a better one. If it runs lean it will read lean no matter how far the gauge reads.
On this gauge it just reads all the way leaned out when I get out of range. In which case I don't care how lean it is, there is obviously a problem.

Not really as the car cycles rich/lean and does some other odd quirky things for very good reasons. A narrowband gauge is mostly just a light show as you have no idea how lean you really are or how to tune correctly for it.

On another note The Knock sensor also makes it runs richer. Not only that but if I am only running leaner in boost the obvious answer is to not boost.

Yes and no. Not richer, but it will retard timing to stay safe so it won't run very well. Not driving would be a better option...

Third, My factory is bad and the car only idles with it in. Another obvious answer, keep the part that works. Now I know that when I replaced the fuel
pump and dropped the pressure it evened out the A/F ratio a lot (except in low rpm's where it is really rich), not only that but with both new knock sensors and a rewire with grounded shielding I still get a knock code.

The electronics can be swapped between the housings. The housing is what increases the airflow, and the electronics are what can fail.

If they're 2 new (and good) knock sensors and are rewired correctly, the only thing that could be wrong would be the ECU at that point, which is highly unlikely. It's more likely to be the wiring as it is 99% of the time...