smoove2022

I am swapping from crossfire injection to TPI. The harness I have for the TPI is from an 86 MAF vehicle. There is a difference between CFI and TPI harnesses concerning the oil pressure switch and fuel pump relay I am concerned about. First, on the CFI body harness there is a red wire that connects to the CFI ECM harness at the fuel pump relay. The TPI harness does not have this. Will I be alright leaving this disconnected? Also, the oil pressure switch for the CFI has 3 pins, where the TPI has 2 pins... I am concerned about the oil pressure gauge not getting a signal. How does the oil gauge work on these cars? Is that what the red wire by the fuel pump relay is for? There appears to be no oil pressure sending unit by the oil filter on my car as some later models have. I did a few searches already and wasn't able to find the info i needed.

Thanks!

Jproz1167

iTrader: (3)

theres a thread in fitting by your oil filter for this fuel pump shut off oil sensor. My LG-4 had it so I'm positive your LU-5 will have it. I think your opening a huge can of worms though buy just trying to simply plug a 86 harness into your 82. I think (correct me if I am wrong) that a CFI harness is of the speed density type and couldn't you extend a few wires to run it as speed density TPI. Not sure if CFI had a MAT sensor though.

Fuel lines are going to be a issue. LU-5 used LG-4 lines and low pressure softlines throughout the car. Main lines probably were like my LG-4 and came up passenger side frame rail.

VSS will be a issue depending on whether your harness is from a firebird or camaro.

I did a TBI conversion on my 82 trans am and just used a entire 1990 harness easier just putting that in and simply plugging the connectors together.

Good luck to you though.

smoove2022

Thats a good point about running the TPI as speed density with the CFI wireharness... My only concern with that is first, a speed density setup has a "map" of the efficiency of a particular engine setup programmed into the ecm. This may not be a huge issue considering the tpi has the long runners like the CFI, and the possibility of switching the prom, but the CFI ecm thinks it is firing 2 individual 2 barrel TBI's with specific properties instead of 2 sets of 4 injectors mounted above the intake ports... which leads into my second concern being that the impedance of the 4 injectors is probably different than the impedance of 2 barrel tbi's...

I've analyzed the pinout of the CFI harness and the 86 TPI harness and they are actually quite similar. Other than the rewire of the fuel pump relay to incorporate the MAF burn off and the separating of the oil pressure switch and gauge sending unit that is. The 86 TPI distributor connector is physically different than the 82 CFI's but it is pinned out the same so I am going to graft in the old connector to use my old distributor. I am going to graft in the old oil pressure switch/sending unit as well and see if it works.

I like the idea of the MAF system over a MAP system. MAF is more accurate than MAP and it will compensate for mods like cam changes better. The one drawback i do not like is the 300hp or so limit of the MAF sensor.

Jproz1167

iTrader: (3)

I was referring to re-pinning your CFI harness at the ecm to run a 730 speed density ECM for tpi not using your stock CFI ECM ..... Have you also considered your Turbo200 won't stand up to the additional torque TPI makes, when mine was a turbo200 it was nothing but trouble. I swapped mine out for a 5 speed.

wdigitog

smoove, i just sent you a PM...i have the same problem with my OPG not being connected after an engine swap! i need help! can't find the connecter and where it connected to on the harness. all the other gauges work...but i think the oil pressure wire was in the engine management harness....

Jproz1167

iTrader: (3)

the oil pressure gauge wires are not in the ecm harness.

wdigitog

so jproz, where do the wires come from? you have the cfi...could you tell me which wire harness the OPS wires come from? it's not the c100 connector..

smoove2022

In my 82 trans am's CFI setup, the oil pressure gauge sender is incorporated into the oil pressure switch. There are three wires at the switch/sender, the tan wire is the gauge signal. The tan wire travels with the ecm harness and connects at the dash harness connector at position "D".