Using an N/A ecu in a TII
 

I recently swapped a TII engine into my car and it runs beautifully. It has an awsome idle and good compression. My problem is when I try to restart it when its hot. It doesn't. I have an s4 tII ecu in my car which is also a s4. It seems like the ecu is stuck in cold start. I thought if I unhook the battery that it would restart the ecu but that didnt do the trick. My question is would it be ok to put the n/a ecu back into the car? It would be like running a turbo on an n/a and plus with the n/a ecu the car starts just fine when its hot. I have an a/f gauge and safc so I can monitor and compensate for the fuel with the n/a ecu, but can I use it?

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Considering emishions are removed. The PS is different the MAF is larger you have a nock sensor and larger fule map a PS on the elbo Twin scroll silinoid.

So far you have the fule coverd MAF is interchangeable PS is swapable. That leaves the nock sensor the sensor on the elbo and the twin scroll. If you work thows out then in theory it should work I say stand alone if you can. However I do not know for a fact.

LOL. The ECU isn't your problem, it's old dirty injectors and probably low compression. You have the standard hot start issues common on even N/A's. Don't touch the ECU, get your injectors cleaned and check your compression.

I thought it was my injectors at first also. I put the N/A ecu into the car tonite and there is no problem starting it up when its hot. Also the compression on the car is fine.

You cant run that TII with that N/A ECU, but you CAN start it.

And for clarification, the hot start CAN be caused by the ECU.

Oh, and more likely, you have a sensor that is causing the ECU to hot start. Our ECUs are dummies, they dont remember shit (kinda like me after a good night on tequila). Once you turn the car off, the ECU has just dumped anything it had (which wasnt much to start with).

Rat

Ok cool thanks J-Rat.

Thats what I thought
Learn something new evryday

Oh, and more likely, you have a sensor that is causing the ECU to hot start. Our ECUs are dummies, they dont remember shit (kinda like me after a good night on tequila). Once you turn the car off, the ECU has just dumped anything it had (which wasnt much to start with).

Rat

Unless you have an S5, they are slightly less dumb.

It is an s5 engine in an s4 shell.

How are u doing this with an S4 ECU? u have to double check the impedianc on your injectors as well the S5 has a nock sensor built into the ECU where the S4 has a stand alone computer for that as well the ECU is exspecting a electric OMP and if im not mistaking that will cause it to go into limp mode without this but maybe not since its a s4 on s5 and not other way around but your engin should allso have 2tps's where s4's have 1

I guess the applicable question here would be....

What ECU is the car using? S4 or S5?

Pay attention people, he said in his original post that it's a S4 TII ECU.

I ran my stock vert ecu for a bit and it ran just fine. Idled great and boosted just perfect.. The only thing was that it ran a lil rich using the 550's and didnt have good fuel economy. But I got haltech now. So yes you can use the n/a ecu.

The vert ECU is the 'special' case where it can generally do both just fine (for the s4's), however, all other ECU's should not be swapped, though they might function to some extent. It's just a plain bad idea.

Shaddup rat..

Gladly, this forum makes my head hurt. Too much PIIDB from the GDFHFK :(

How about STFUSRAT

How about LHTD Mr.Rat. I bet it won't take long for you to figure that one out. ;)

You two need to join the military service and learn some discipline! humor

I used all of the S4 electronics basically. I used 1 tps on the throttle body and instead of switching front covers I decided to just run premix. As for the knock sensor I just ran the single wire from the sensor to the box itself. Also as for the injectors I just used low impedance 550's primary and 720's secondary. If I wanted to run the high impedance S5 TII injectors I could have just removed the resistor pack.

I was just checking you had your stuff straight. nice job

i already wear the salad suit!

I had my tII engine running on a NA ecu for over a year @10psi and still going. I agree it is not the best solution but that is all I had. But it worked much better with the NA ecu than the turbo ecu. It was smoother and more bottom end pull.