coolmike711

iTrader: (7)

Fresh 87 TII rebuild and the car would not start. Check every possible connection and sensor still will not start.
Put in a N/A ecu it started. Got a another turbo ecu because I thought the first one was no good. Put it in and still won't start. Put in the N/A ecu again and it started.
Someone please tell me something..........

HAILERS

What are the numbers on the Turbo ECU's? LIke N332 or N333? or???????????

coolmike711

iTrader: (7)

N332. That's what came with the car. The funny part is that I put the N332 in the N/A and it started with no problem.

HAILERS

Yeah. Real odd. I can put a N332, N333, N326 or N327 in my car and they all will START the engine. I'll think on it a bit and if I come up with any thought I'll reply. I can't think of WHY right now.

EDIT: A THOUGHT! EEEK. Well, rebuilds flood easily sometimes, not all times, sometimes. So the non turbo ECU MIGHT be delivering too much fuel? Meant for 460 injectors and you have stock 550's. Only thing I could come up with in the last few minutes.

I think I'd use the non turbo ECU and get it running up and hot and put some time on it, then try the Turbo ECU again????

coolmike711

iTrader: (7)

It is weird. Spent a day now trying to figure this out. With the N326 in the Turbo it started with one crank and the rpm's stood firm at 750.

pistones

iTrader: (5)

the only differences in fuel system is the fuel pump resistor relay, if i remember correctly the base model i worked on didn't have it but turbo models do. i think that it only makes a difference under idle and cruise, not starting.
is this a conversion of any sort? are you using any NA parts other than ecu?

coolmike711

iTrader: (7)

This was and is a 87 TII that was rebuilt. All TII parts. Just doesn't make sense.

HAILERS

I should have said the non turbo ECU MIGHT deliver LESS fuel than the Turbo ECU, therefore not flooding the engine. Other than that is does not make any sense at all.

The TURBO ECU does somewhat control the fuel pump resistor relay assy, but only in whether it sends a full batt voltage to the fuel pump OR cuts it down to 9vdc. Even then, IF memory serves, you get FULL batt power during START.

Or put another way, the fuel rail will see 39psi in either mode the resistor relay is in at a given time during starting.

This is done thru a green/red wire on pin????????? pin 3D from the ECU to the fuel pump resistor relay. I kinda doubt that is the problem. The non turbo ECU would not have that wire from 3D. The 3D on a non turbo goes god knows where...oh, inhibitor switch for a automatic car. Again, I can put a non turbo or turbo ECU in my turbo car and it will start and I can put a turbo ECU in my non turbo car and it will work as far as starting goes.

coolmike711

iTrader: (7)

Apparantly the N332 is missing some kind of input that it needs to idle and the N326 does not need it. But like what Hailers said and what I did, the N332 works fine in the N/A. What the ....?

Force Fed

Is there a bent pin in the computer-side plug maybe?

coolmike711

iTrader: (7)

no bent pins

HAILERS

Post number nine might leave one to think the Turbo ECU will start the engine but the engine won't hold an idle. I'm WRONG about that, right?

The pin outs are virtually the same except for, I think, four pins. But, like I say, I can use a non turbo or turbo ECU in my stock Turbo car allday long and vice versa.

Tell you what I'd do. PUll the CAS out of the other engine/car/shelf. Attach it to the Harness on the turbo car. Key ON. Spin the bottom gear of that cas with your fingers. Listen and look for spark and fuel injectors clicking. I'm talking using either of the non functional TURBO ECU'S.

Just a simple way of finding out if those ECU can support spark in that car and fuel injection pulsing. Seems if you hear spark and fuel injector clicking, then I might be right about too much fuel. Or just to find out a clue as to what is wrong.

Could backprobe each pin on the ECU with the plugs attached to the ECU and compare them with the FSM.

Yeah. Crazy problem. Turbo car with turbo ECU won't work but a non turbo ECU will work. Stupid problem. Odd. Shouldn't happen.

How about key to ON, jumper the fuel pump check connector and listen for the fuel flowing thru the rails and retuning to the tank. Turbo ECU. That would/should eliminate a possible fuel issue (hate that term, can't believe I used it) fuel problem.

coolmike711

iTrader: (7)

That's what happened the first few times I cranked it. It would start for 2 seconds and then shut off. Like if the ECU got a reading it did not like and shut the engine off. So yeah I guess it won't hold idle.

Force Fed

Can you keep it running w/ the pedal or no?

coolmike711

iTrader: (7)

no, will not stay running when i hold the pedal down

Can you drive the turbo with the n/a ecu in it without problems?

HAILERS

This thread is getting long and I forget easily. Question: Did you put the Turbo ECU in the non turbo car? And will it run in the non turbo car? I'm making an ASSUMPTION you have a non turbo car also, but could be really wrong on that.

Here's the Way Stuff Works on a RX-7 during Start (see attached jpg). The AFM is not used for fuel delivery during Start. The ECU uses an internal fuel map for Starting and it uses that map IF the ECU sees a Start signal from the start circuit.....if rpms are under 500rpm..........and the water thermo sensor signal (determines amount of fuel injected by *F temp).

So you KNOW the engine will Start with the Turbo ECU, but won't keep running. I've seen that happen with a Disconnected water temp sensor on the back of the water pump housing. Too little fuel will be injected during Start and the engine will be very difficult to start because of too little fuel. The ECU defaults to 180*F if that sensor is not connected, and as you can see on the attached jpg, very little fuel will be injected during Start.

Then again, if that sensor is connected up and working, then the engine will start, but once over 500rpm, the AFM will not determine the fuel amount (plus make the fuel micro switch in the afm to keep the pump working). A bad AFM would keep the engine from idling/running after Start. But yours works just fine with the non turbo ECU. So that just about eliminates the afm as the bad player.

I'd at least check out the water thermo sensor for being connected up.

The STARTING of the engine with the turbo ECU makes one go back to the fuel angle, one way or the other. Can't be the afm or it's internal fuel switch. You might get the engine hot using the Non turbo ECU. Then swap the ECU's to the turbo and see what happens. Get the engine fully HOT before doing that. In fact that's the first thing I'd do this morning. Hot engine using the non turbo ECU then swap to Turbo ECU.

Just rambling.

Also, if the ECU does not see the Start signal, then the ECU uses the AFM during Start, instead of the internal fuel map in the ECU. That also results in too little fuel during start because the internal map isn't used and the afm is used. Start signal is seen on pin 3B for turbo or non turbo cars. It would be batt voltage on that pin/wire, only when the key is HELD to Start.

I'm sort of implying that the non turbo ECU is causing enough fuel during the start and idle but the Turbo ECU isn't. The HOT engine idea would prove that one way or the other. If the engine is hot, then the Turbo ECU has no good reason to not work. Hot would be approx 180*F, the default value for a non working water thermo sensor. Plug away at it, you'll fix it.

coolmike711

iTrader: (7)

So we decided to put the N326 in, start and run the car. So in doing the timing and idle adjustment with the N326 notice that the BAC and Variable Resistor needed alot of adjustment. So the idle and timing was set with the N326. Then we put the N332 back in and it started and idled. It was not smooth but it finally ran with the N332. Then we did all the adjustments to the CAS, BAC and Variable Resistor and now it's running good.
The problem was that with the old engine my brother had to do alot of adjustments to keep it running, so when we put in new the engine all those adjustments would not make the new engine run.

HAILERS

That's cool. Now you have spare parts! (ECU). Be cool.

By the way, I've found out in the past, that if a non turbo boost sensor is used with a Turbo ECU, the idle is not so good and vice versa i.e a turbo boost sensor used with a non turbo ECU makes for a crummy idle etc.

The output of those two sensors is of a different value at idle and on up the range. Just FYI.

coolmike711

iTrader: (7)

Yeah man it was crazy. The next step I hope will be stage 2 BNR turbo and front mount intercooler.
Can I block off the Air Control Valve?

HAILERS

Probably, if you don't have to pass an emissions test each year.

You'll need to find a source of vacuum for the boost sensor if you do that, since the source is directly from a nipple on the ACV on turbo engines.

In fact if that is the case (going to remove the ACV), you might make that your next move. ACV can leak air into the intake if they're corrupt. So say your engine ran just fine, then you remove a corrupt ACV. The idle will change and become crummy due to the air that WAS leaking into the runners, and is NOT leaking into the runners since you removed the ACV. Something like that.

IF you find the idle has changed after you remove the ACV, and you have a good gasket on the blockoff, then most likely the ACV WAS leaking a bit of air when installed.