New and need some help with m20 turbo

[BayE30]

Hi everyone, I recently sold my e36 m3 to get into a turbo e30. The car is an 88 325is that i bought already fitted with a turbo but had a missfire and wasnt running. The car as of now is running an ebay turbo thats a t3/t4 with an internal waste gate (will upgrade when car is running right and money allows), it has an older begi cast adjustable fuel pressure regulator, m30 afm, 36lb injectors, tcd turbo chip in a 525 motronic 1.3 ecu, and runs a 3" straight exhaust into one muffler (no cats or resonators).

List of replaced parts: New 36lb injectores, new ignition coil, new distributor cap and rotor, new ignition wires, new m30 afm, new tps, new fuel pump and fuel pressure regulator, intake manifold gaskets, bitch tube with all new hardware, throttle body gasket, idle control valve hoses and cleaned the icv, new o2 sensor.

Now my problem is that when i hit the gas pedal to rev it, whether the car is warm or cold, it revs smooth and then when i let off the gas and its returning to idle, it dips down to 500rpm, feels like it is almost going to stall, then shoots to 1100rpm, and then goes right down to 700 rpm idle and is rock solid there until i touch the gas again. At idle my car throws a 1222 code and then when i rev it goes off then returns a couple minutes after its idling. My afrs are about 13 when warmed up and my fuel pressure to the rail is about 50 psi.

Any thoughts are greatly appreciated.

[ADlBOO]

Why are you running a m30 afm if you have a m20? When was the fuel filter replaced last?

[BayE30]

It how the p/o had it for the slightly large size and he told me thats what the tune is set up for. Sorry the fuel filter has been replaced as well.

[ak-]

Even though the setup doesn't sound too dependable I'm going to assume your idle tune is "GOOD".

Are you running the AFM blow thru or draw thru?
If it is draw thru, you have to have the blow off valve recirculated.
That rev is possibly leaving the valve open and creating a vac leak till it picks itself up again.

[ADlBOO]

Even though the setup doesn't sound too dependable I'm going to assume your idle tune is "GOOD".

Are you running the AFM blow thru or draw thru?
If it is draw thru, you have to have the blow off valve recirculated.
That rev is possibly leaving the valve open and creating a vac leak till it picks itself up again.

Thats a good point, forgot to think about the turbo part. Sounds like its more of an arrangement problem, than it is a running problem.

[BayE30]

I believe it is a blow thru although im having a hard time grasping the difference. The afm is on the intake side. It goes from the intercooler, to the bov, afm, and then throttle body.

[ADlBOO]

If it is a blow through, seems like you need to get the bov closer to the turbo, maybe before the intercooler. Its almost like the blip, is spooling the turbo enough to give a surge of boost, and the bov isnt dumping it fast enough. And with it being so close to the afm there isnt enough expansion room in the system to "absorb" some of that boost.

[BayE30]

Here is a pic of how close they are together to give you an idea.

[MR 325]

You need to ditch that whole Motronic setup pronto.

Get yourself a plug and play Megasquirt from somebody like whodwho and have it tuned properly.

Everything else is just a guess and a band-aid.

[BayE30]

Ok so you think the problem is the ecu cant handle everything that has been changed and with a properly tuned meqasquirt i should be good to go?

[ak-]

Ok so you think the problem is the ecu cant handle everything that has been changed and with a properly tuned meqasquirt i should be good to go?

Yes. Motronic cannot handle blow thru setups especially let alone minor boost.
I just didn't want to be the one to tell you.

[BayE30]

haha yea....its set for 10psi as of now but it looks like alot of the parts i replaced was for nothing but learning how to work on this engine.
I was reading up on megasquirt a bit and is that why a lot of m20 turbos i see have no afm because its not needed?

[einstein57]

Motronic usually can't handle above 30lb injectors unless you had someone who really knows what they are doing burn you a new chip. A TCD or fleabay chip wont cut it.

[BayE30]

I opened up the ecu and it had the tcd chip in there, highly doubt it was reburned because this turbo setup definitely seems like it was done on the cheap for most components. Looks like ill end up buying a megasquirt plug an play unit. Im assuming that the base tune that comes with the unit be able to run the car so i can drive it to get tuned?

[ak-]

Could be yeah, just don't go into boost.