Engine Idle quesion... (IAC, MAP, TPS, Temp units)

[skidoo_j]

You haven't ever replaced the TPS, right?

 

Nope just tested the ground, and set the 17%. I did test the resistance and it appeared linear through the operation. However I have ordered a new one as well as a new IAC.. Once they're installed every sensor will be new. the only remaining electrical that will not have been replaced would be the ecu, wire harness, stator(sensor in bottom of distributor?) and the coil. as i've already replaced the rotor, cap, plug wires, and all sensors that I'm aware of and found.

 

I may have to pull the ecu and start testing sensor wire resistance to see if maybe one of them is bad. the ground sides seem to all be good.

 

then maybe it'll be back to replacing all vacuum lines even though i can't find a leak maybe one develops with vibrations.

[cruiser54]

Do everything one at a time so you end up knowing what it is.

 

ECU connector refreshing fixed a buddy of mine's 88 and another guy on a forum had it fix his after they each went down a road similar to yours.

[skidoo_j]

Do everything one at a time so you end up knowing what it is.

 

ECU connector refreshing fixed a buddy of mine's 88 and another guy on a forum had it fix his after they each went down a road similar to yours.

 

I've been doing one sensor at at time. and will drive down the road. what's weird is with each senor i replace it seems to go away. and when i think i've destroyed the beast it shows it's ugly face.

 

 

what do you mean by ECU connector refreshing?

 

I was planning to find the pin out in my fsm then disconnect it and just use a jumper from in the cab to where each senor is and see if any resistance.

 

They definitely didn't design them for trouble shooting electrical. They could have given a few extra inches of wire here and there. I don't even have enough slack to get to the back of the fuse box. I can't imagine how tight the wires are near the ecu.

[cruiser54]

Actually, the ECU has a decent length harness on it. I would remove the ECU, unplug the connectors, spray out with electronics cleaner both the ECU side and harness side, and then tweak the female receptacles a skosh tighter with a small pick to ensure they grab the pins tightly.