LT-1 Retrofit Questions

[alocker]

I know there are some LT-1's around here, so here goes. This is going into a 1972 Malibu with no emmissions equipment.



It seems that in EFI applications, the closer the O2 sensors are to the motor, the better. Will it matter if I mount them 4 inches further back in the headpipe reducer to avoid messing up my coated header by mounting in the collector?

The ECM is from a 95 TA. Does the ECM read the oil pressure sensor for the fuel pump or other functions or is it just for the gauges??? I run mechanical gauges and would like to remove the rather large sensor.

Thanks guys!!

[Samckitt]

The O2 sensors for an LT1 are heated, so moving them 4 inches isn't going to matter. I moved mine to the collector on full length headers. But then again haven't run it yet to be sure about the first sentence. They require heat to work properly, on the heated ones, it doesn't matter as much where they are placed.

I have the 95 PCM as well, I had the factory harness reworked by John at speartech.com. It didn't use the oil pressure sensor. I think it is just for the fuel pump relay.

[Mark Smith]

preety sure sensor works with fuel pump relay to shut off pump in case of oil pressure loss.if car rolls over or whatever fuel will not keep pumping all over the place.

[alocker]

Ok, I guess I will keep it. I thought maybe the RPM signal was for fuel.

[Samckitt]

I was thinking it was a backup for the fuel pump in case the relay goes bad, that this will close the loop once it reaches pressure. It will work without it, mine does. Just carry a spare relay. :-)

[alocker]

I was thinking it was a backup for the fuel pump in case the relay goes bad, that this will close the loop once it reaches pressure. It will work without it, mine does. Just carry a spare relay. :-)

Im not sure what the oil pressure sender has to do with the fuel pump relay going bad. It was my understanding that the ECM controls the fuel pump relay directly. Am I misinformed?

[Samckitt]

The PCM does control the relay, but I was thinking the oil pressure switch was a backup in case the relay went bad. So when you turn the key on, the fuel system is not pressurized as normal, but once you start cranking it & oil pressure builds up the switch closes & the fuel pump runs. I'll have to look for that info. I know you can run the system without it, because I am not using mine.

[WS6]

Just be sure that your collector seal is very good. Any leakage will cause the O2 to read lean on that side.