Creeklurker

1997 jeep cherokee 4.0
Codes are as follows
P0123 : throttle position sensor volts
P0118 : engine coolant temp sensor circuit high voltage
P0320 : crankshaft position sensor circuit
P0113: intake air temp voltage high
P0112: throttle position sensor voltage low
P0320: ignition reference/ crankcircuit
P0123: throttle position sensor voltage high
I have 5volts to crank,cam,iac,tps,map
I have cleaned all grounds
I have continuity through all grounds
I have checked pcm I have power coming out going to all above sensors as well as inflow signal to pcm
I have a weak spark it stumbles on first crank on starting fluid but it has to sit for a min can't spray and crank immediately
Previous owner replaced computer seems to be good
no fuel whatsoever when cranking ,fuel rail has great pressure holding above 42 psi
I have replaced rotor cap ,button ,sparkplugs,wires, crankshaft position from auto zone 2x
Ignition switch, ignition coil 2x
On live data it's saying my tps percentage is 100% with truck off not touching gas
I found another 97 running xj he started it up frame was rusted gone I took the pcm , crankshaft, the whole throttle body with all sensors tps,iac,map
installed all on my jeep same results crank no start, same codes came back on new pcm
I tried the clock spring trick but left all fuses in so I have a ground or power problem can someone point me in specific detail how to chase down these wires or grounds not an electric guy

lawsoncl

What do you see for voltage if you measure at the ground wire at the TPS? A bad ground to many of the the sensors will throw reading too high code. All of those grounds land on the stud on the passenger side that holds the dipstick tube. I would remove and clean all those grounds really well and see if that helps.

Creeklurker

Hook volt meter to ground at battery and test ground on the tps sensor ? I will also clean all grounds again and re attach

lawsoncl

Yup. Measure from battery negative.

Creeklurker

With key off its showing 0.16 volts

lawsoncl

That's a bad ground, imo. Key off, I'd expect zero actually.

Creeklurker

I have the grounds exposed It ties into everything including transmission sensors what's the best way to track down where it's bad so many wires

Creeklurker

I found a break in the tps sensors it's so old it has tarnish built up around the exposed hole in wiring harness

Creeklurker

I fixed wiring
pcm is saying no codes
crank no start
no spark