I am in the need of some help. I have a 1995.5 that does not want to start with the TPS plugged in. It will run if TPS is unplugged and starting fluid is used. Will continue running if TPS is plugged in after running but stumbles and studders at different times.
OEM TPS.

When I can get it running it runs quite smooth and can idle on its own after a couple of seconds.

believe it is a 1995.5 because of the 3 pin coils.

Harness side. A is top pin when installed.
A - 5v with key on
B - Appears to be connected to ground - No resistance between pin socket and chassis ground.
C - Did not measure - Unsure how
D - Did not measure - Unsure how

TPS itself
A - Variable resistance between pin B depending on TPS position. I believe this should be correct.
B - See A
C - Continuity with D at 0% TPS and no continuity at > 0%. I believe this is correct
D - See C

I am unsure what else to try, not 100% sure it is TPS related but its my best guess as of right now.

Bonus issue, when running the tach does not work. Randomly moves between 200 and 2k RPM with no rhyme or reason.

 

Check all of your main grounds. Motor to frame, battery to frame, battery to PPF

 

Checked and cleaned all grounds according to my Haynes manual. No luck. Jumped fuel pump to ground in diag box and no luck with that as well.

 

Started by into troubleshooting this. Verified resistance of coils is in spec according to Haynes. Have spark at all 4 cylinders. Had wife attempt to start while I felt and held screwdriver on injectors to my ear. I can't tell that the injectors are firing. I can't hear or feel them. Fuel pump definitely primes. Weird that with starter fluid it will try and start, and if it catches it will stay running.

The fan also will start and stay on sometimes if it fails to start. That doesn't seem right. No check engine lights.