What kind of affects would you get if someone ran a obd1 ecu with with a 97 3800 TB and all other sensors? Would it ever run right?

Specifically speaking - most of the sensors are the same. The 3800 ODB1 doesn't use a MAP sensor. The 3800 SC S1 I looked at had two CTS sensors on it, but I assume only one was used for the ECM. It also was a two wire sensor where most 3800 S2s use a three wire sensor, even if they don't have a temp gauge.

I do believe they use totally different MAFs on them.

---

Now generally speaking, are you talking about a 3800 ODB1 computer or a 2.8 or 2.5 ODB1 computer. There is no chance of a Fiero computer running a 3800.

I suppose a ODB1 3800 ECM could be made to run a series 2 engine. You would have to rewire things. You would also have to tune it to run that engine. So yeah you could but there would be little reason to do it.

Also the ignition system of a 3800 is totally different from the ones on either the 2.5 or the 2.8/.

[This message has been edited by phonedawgz (edited 09-06-2011).]

If you mean the Fiero ECM, then no, it doesn't support all those sensors. If you mean the later OBD1 ECMs like the 7730, then maybe, though most likely you will need the same type of sensors, but for the OBD1 ECM. Likely the sensors are different between the OBD-I and OBD-II ECMs that came on the 3800.

As far as I know it's a series 1 3800 ecu running the series 2 engine. I'm going to wire it up to a 98 or newer PCM. Just wondering how crappy it would make the car run? Definitely has bad fueling issues. Starts but spits and sputter and does not want to stay running. Have over issues to fix also but like I said just wanted to know what the affects are. If it can't read the maf that would lead to fueling issues for sure.

Well, knowing absolutely nothing about the swap in question, I can't really say what is wrong exactly. If the sensor data doesn't match what the ECM expects, then you're going to have problems. But if the right sensors are on it for the ECM being used, and you just plug in a new OBD-II ECM, it will probably run worse. And you can't judge whether the sensors are the same or not, based on how many wires are connected. If you're running an OBD-I ECM, and all the harness and sensors are straight from the OBD-II setup, it's not going to run right. So if that's what you have, and you already have the OBD-II ECM, go plug it in.

The difference between the two wire CTS an the three wire CTS is the third wire of the CTS connects to the temperature gauge sender. The CTS portion of either the two wire or the three wire are electrically the same. The CTS of the 3800s use the same negative coefficient thermistor as the 2.8 and 2.5.

The two wire IAT also uses the same negative coefficient thermistor. That would be for all the engines in this discussion.

The series 1 TPS uses a different connector than the series 2 but electrically they are the same.

Oil Pressure Senders are the same, but they don't make any difference to the ECM since they don't connect to them.

The IAC motors are the same between S1 and S2. The IAC motor has a quite a bit different connector on the 2.5/2.8. I don't know about the electrical aspects of the two.

The knock sensors are different between S1 and S2. The connectors are different also.

The EGRs are quite a bit different.

The same EVAP solenoids can be used on either engine. The connectors can be quite a bit different however.

Manual transmissions don't make any difference.

Automatic transmissions need to match up to the ECM. The different automatic transmissions use quite different connectors and different wiring.

ODB1 ECMs(PCMs) have a totally different footprint, and connectors and wiring from the ODB2 PCMs

[This message has been edited by phonedawgz (edited 09-06-2011).]