Intermittant start (with codes)

[TimboSHO]

Ok, it all started about a month ago. First my 89 would die really intermittently (usually when coasting to a stop with the clutch pushed in) and then it would usually restart quite hard. A little while later the tach would bounce to zero and back once in awhile (usually when it was wet out). These symptoms kept reoccurring more frequently until last Saturday. The car had hot-soaked for about 4 hours and it wouldn't start. The first time it tried there was a really loud backfire (can you say echo in a parking garage?). Then it would just crank with no fire. About half of the time there was no tach, and the other half there was. My wife and I sat there for awhile for the traffic to clear (about 20 mins) and then tried to start it. It started, but wouldn't idle. I limped it home and kept the rpms up. For the next 3 days it started and ran fine with no problems. Then after work one day (after about a 4 hour hot-soak) it did the same thing. Waited 20 mins, and it started and ran (but couldn't idle again). Then after work yesterday it didn't start again, and wouldn't stay running at all. The tach would drop when the rpms were below 2K and it would backfire really bad. I left it there and borrowed the boss' POS S-10.
Today I checked the codes and had a
24-IAT out of range
52- PS Pres. SW open
14- PIP Erratic signal
Now, the 24 is just because the car wasn't warmed up, and I'm not really worried about he 52, but the 14 would probably be the CPS, right? I am just wondering if I should be worried about the backfiring? I will check the timing and for crank cancer when I do the CPS, but I just want to post this to see if there is anything I'm overlooking? Thanks. I'd rather not do a CPS if the motor is junk either. Thank you all for reading this gargantuan post

 

[93rev2sev]

Check grounds and vacuums. Other than that...is crank/cam sensor time.

 

[93rev2sev]

OH, and probably waterpump (maybe just the housing to block o-ring will be needed)

 

[TimboSHO]

New crank sensor and it fired right up. I did the water pump not too long ago (ok, i checked and it was 50K miles) and it's not leaking or noisy. So my SHO should make it to 200K now. Yay!