Could be the TPS (Throttle Position Sensor). If the PCM is getting a signal that the throttle is wide open it'll cut the fuel supply. Give us a few minutes to look up how to check the TPS.

Code 21 should be TPS Voltage High.

Voltage gets higher as the throttle opens so we might be headed in the right direction. My Chilton'* manual gives a very poor desciption on testing the sensor. I'm going to look at a wiring diagram but if anyone knows how to check TPS voltage please jump in.

how about you just mod it

http://www.geocities.com/carnutguy/c...hancement.html

I checked TPS and i get .41 at idle and 4.00 at WOT (engine off) . That'* a correct value.
What else could be causing no injector pulse?

Let'* go back to the battery. Make sure both ends of all the battery cables have good clean connections. Maybe even swap batteries again. If that doesn't help check connections going to the ICM & PCM.

I'd check for corrosion inside the ground from the battery. Flexing over time cracked the sheath and allowed water to pool in mine.

I bought this battery a week ago, it'* all tight, and clean.
When there is no start, engine is cranking like it should be, spark is there, positive side of injector plug is ok, but there is no groung pulse. Maybe it'* the wire harness. Where can i find diagram of PCM pinout? Ii'll check it there, and check the ground wire for resistance.

The wiring diagram I have for the 93 isn't the best but here'* what it'* showing for PCM grounds.

Black Connector
A6 - Blk/Wht
B6 - Blk/Wht
D13 - Blk/
C13 - Wht
That'* the way the diagram is showing D13 & C13. They're probably both Blk/Wht

Orange Connector
D2 - Tan

I prefer to test the grounds with a 12 volt test light. A meter could show it as good while a bulb could be dim.

You may not find it grounded. The negative side of each injector is switched on & off by the PCM. It'* a pulse type switching signal to ground each injector to fire at the appropriate time during an ignition cycle.

I may have misunderstood what George wanted to check. The grounds I listed above are for the PCM. I'd still check those, if the PCM isn't properly grounded the switches in the PCM wouldn't be able to complete the circuit.

These are the terminals that go to the fuel injectors.
#1 - C15 - Blk
#2 - D16 - Blk/Lt Grn
#3 - C12- Blk/Pnk
#4 - C14 - Blk/Lt Blu
#5 - C16 - Blk/Wht
#6 - D15 - Blk/Yel