I have a 1987 IROC camaro that is currently running a 1227165 ecm. I have a Vortech S/C all hooked up but not running as the engine was just rebuilt. I am going to put around 1500 miles to break the engine in before putting the s/c on it. I have (2) 1227730 ecm's and a 1227749 ecm on hand and am going to repin the car within the next few weeks. I don't plan on running the S/C until next year. My question is, Can I put the 749 ECM on the car now and just run a 1 bar map sensor? Then when I put the S/C Belt and air redirector onto the car put the 2 bar map on? I know the 749 handles boost and retard and the 730 doesn't. But, would it hurt anything if I wasn't running any boost pressure until breakin occurs.

 

No problem using the 1-bar MAP, then switching to the 2-bar later.

Also, you can run $58 (Syclone/Typhoon) code just fine on a '730, if you wire it up as if it were a '749, in most cases, especially if you're using high impedence injectors.

There's plenty of info over in the DIY PROM forum regarding the $58 code and '730/749 interchange.

Also, just to make sure you know, you'll need to use a '730 V8 memcal, even if you do use the '749.

 

Even without boost, you can still use a 2 bar map sensor, and that'll give some time to start a good VE table.

 

Ok, I have all the parts to make it a 749 system now. I see it doesn't make a difference being a 1 bar or 2 bar unless you are running boost. I plan on repinning either tonight or this Sat depending on the weather. I was going through the conversion table and did find a few things that weren't clear. Having only worked on MAF systems, This might sound kinda simple but, where is the recommended Spot on a TPI engine to put the vacuum line for the map?? The next question is a little more complex.

On the repinning on Step 2 from a 730 to a 749

I see that the 1227730 F2 harness connection says


730 ecm 749 ecm
F2 --------------------> disconnect (AIR pump Solenoid)

Is it telling me that I am not to use the F2 connection anymore? Or should I disconnect the Airpump Solenoid and which one should I disconnect, the Green or the Gray Plug or Both?

And the last question

730 ecm 749 ecm
C1 --------------------> B12 (VSS output for cruise)

Looking further down in the instuctions it is saying that the 730 ECM signals not connected are

BC1 (VSS output 2000ppm)
BB9 (VSS Low)
BB10 (VSS High)
BB11 (VSS output 4000ppm)

So, after I repin to 730 should I then use the BC1 and pin to C1 on the 749?

 

I finally got my 87 IROC repinned from a 165 to a 730 ECM. Had a few problems like the Vats was still enabled and the Timing was a little flakey. But found the computer kicked out a Map High code.

I pulled a 1 Bar Map from a 1992 Buick Regal outside and installed it in the car and the engine came alive. Alot of thanks goes to my friend who is a computer / IROC-Z Guru. With his knowledge and my money, This might actually work LOL..

We chatted a little tonight about switching to the 749 ecm and he said to just keep it like this for now until I get ready to put the belt and oil feed line on the Supercharger. Then go for the switch. Shouldn't take more than 1/2 hour to repin the 6 or 7 pins on the ecu. Does anyone know why you can't run the 2 bar map on the 730 ECU though?