tonyroc14

So I am having a hell of a problem here. I am going to outline everything that has happened, and what I have done to try and correct the situation.

This started out with me noticing my Tachometer was jumping around like crazy once I hit 3500RPMS. The tach would literally jump to 6k and back. Also, I would get a P0335 every so often. At first I thought my transmission was slipping but upon further diagnostics, it was a false reading from the tachometer.

I checked my TPS because the TPS commands the transmission to shift, and it was having difficulty with this tach ****. I checked it and it was slightly out of specs so I replaced it. No change.

I do not remember what prompted me to the next step, but my repair process included replacing the fuel filter, pulling the CKP and checking for reluctor wheel contact. It appeared fine. So I re-installed and performed a CKP variation re-learn. Of course when I pulled the fuel filter, I pulled the Fuel pump relay and ran the car to depressurize the fuel system. Also, to note, the truck was quite low on fuel. The fuel light was on. After that the truck had developed a hard start, and a misfire on cylinder 4.(can not feel, or see the misfire) No change to the jumpy tach.

The variation re-learn involves running the car in park up to 5100 RPMS. So I assumed that the excessive RPMs may have knocked some corrosion loose in the Cap or something, so I proceeded to do a tune up.

New cap, rotor, plugs, and wires gaped at .060. No change. I had, at one point in time, or all at once during this process the following DTC's. P0101, P0300, P0304, and P0355

I cleaned the MAF, that resolved the P0101.

I checked for fuel pressure. It was steady at 62PSI with key on engine off, and once I started it it was at 58psi, and as I revved the engine never dropped below 52PSI. My vacuum holds steady at all times during engine operation. I could not find any vacuum leaks anywhere. The diagnostic computer shows that everything is running great, the fuel trims look good, the O2 sensors look great. The Engine temp sensor reads correctly...

At this point I discovered that the tach was not correct, so I replaced the coil, assuming that's where the tach gets it's feed from. No change.

I pulled the distributor, and found the drive gear to be worn, but not excessively, however I thought the bushing was worn, and I wanted to change the cam sensor, so I replaced the whole distributor. Zero change.

I found a wiring diagram that shows the tach gets its Engine speed from the PCM, and the PCM gets it from either the cam or the CKP, sensor. It didn't specify. So since the CKP hasn't been replaced, I replaced it. That corrected the tach. I can drive WOT and the car shifts perfectly now, and shows proper engine speed. However, my hard start, and Cylinder 4 misfire persist.

The hard start does not seem dependent on weather conditions. If I start the car within a minute of running it'll usually start right up, but any amount of time, 5 minutes of more, and the thing takes 5 seconds to start. Once it starts its rock solid... The misfire only happens at 2450 RPMS all the time. All the freeze frame has been at 2450

To try and further diagnose, I sprayed some ether in the TB to try and start it that way. It still cranked and cranked before starting. I also bypassed the fuel pump relay and left the fuel pump on constant and tried to start it that way. Still, same thing.

So that's as much that I can remember. Hard start, #4 misfire.