I have a 1998 LS1 from a Firebird that I'm installing in a 1990 RX7. It has been decked and cleaned. Crank turned and original rods trued and pistons reused. Original bore. It has a 228/230 cam with 112 lsa with 799 heads that have been milled .020 with mild porting.
I have the stock 1998 manifold and injectors on the engine.
I have the stock harness and ECU but was advised to purchase a different ECU so the tuning would not be as difficult.
I purchased a 2000 Tahoe DBC ECU and Harness.
I also have a 2005 Tahoe intake with injectors.

My questions are,
If I use the 2000 ECU and harness with the 1998 injectors will the injector conectors fit?


If not, Is there a way to use the 2005 injectors in the 98 intake with the 2000 harness?


Should I get larger injectors to provide better performance with this set up? Suggestions?


Anyone here do the LS harness mod. I would like it extended to put the ECU in the passenger dash?


Not looking to go to the LS6 intake right now. Just trying to get it running.
This is a street car to play with. Maybe NOS in the future but not now.

 

I believe the injector connections on the truck harness are different and there is no way that I know of to use the truck injectors on the car fuel rail and intake. If you are already in the process of modifying the harness to extend the PCM connector, it should be a simple fix to take the '98 harness injector connectors and solder them onto the '00 harness. The stock car injectors should work just fine for your set up as is.

 

Thank you for the info. I'm going to use the 2000 ECU and harness and change the injector plugs. I may go to larger injectors once I get it running.

 

The main difference youd want a truck harness is the location of the PCM. Trucks have the PCM on the drivers side, fbodys on the passenger side. 98 PCMs are fine, they are NOT harder to tune. Thats an internet myth created by idiots that needs to die. If youre set on the truck setup they make injector adapters that are plug and play. 98 car will also have a 3 prong temp sensor and trucks will have the 2 prong. I would recommend larger injectors yes! Also, as injectors change from platform to platform the connectors AND the length changed. So keeping everything from one vehicle style makes piecing parts together much easier IMO.

 

Why do some people say the 98 computers are harder to tune? I'm not a tuner and this is the first time I'm not going carbed.
I spoke to Tom at LT1350 and let him know what I have. After speaking to him I think I will be using the 1988 harness so I do not have to use adapters or change the injector plugs. I will also be able to locate the ECU behind the glove box in the car.
He said he can repin the harness to work with the 2000 ECU if I want to but if there is no reason to, I'll use the 98 ECU and save a few dollars. So what's the negatives in keeping the 98 ECU?

 

I think the processor is a tad slower and it doesnt have all the abilities to do some stuff that the newer pcm can. The difference is for your average heads/cam/intake car its fine. You wont have any issues.