95 S10 4.3 W vin not firing injector

[Bigdaddy0690]

I have a 1995 LS S10 pickup with a 4.3 that I totally love. I have replaced the complete Distributor, Cap Rotor Plugs and wires. I have replaced the fuel injector spider. I have replaced the ECM ,Crankshaft sensor and wiring. I have replaced the coil and ignition module. This vehicle runs great and dies out of the clear blue and will not start for an hour or 2 or maybe a couple of days. I also have replaced the fuel pump. Fuel pump pressure is 65 psi. I am at a loss does anyone have any suggestions?

[DelCoch]

I know you said you replaced the Crankshaft Sensor and wiring, but did you replace the wiring all the way from the ECM to the Crankshaft Sensor. This wire has a tendency to occasionally rub against the engine and short-out which causes a problem like you're having.

[Tech II]

Do you have fuel pressure when it won't start? Spark?

If you have pressure and spark, then try spraying carb cleaner into the intake, and see if it starts......

[Bigdaddy0690]

I have 65 psi at the fuel pressure point. I do not have pulsating voltage at pin # 2 the serial data point. I understand that this would keep it from starting.

[Bigdaddy0690]

Well I sprayed Carb cleaner in the intake and it fired right up. I do have 12 volts to my injector but the injector is not spraying fuel. I do not have a noid light right now. I am try to get one.

[Bigdaddy0690]

Yes I checked all the way. Thanks for your advise. I have 2 issues right now now voltage to pin 2 and injector not spraying. New spider assembly and fuel pump.

[Bigdaddy0690]

Starts great with carb cleaner. Goes to unusally high idle until it runs out of carb cleaner

[old_master]

You're right, fuel starvation! The red wire at the injector must have battery voltage at all times when the ignition is in the START and RUN positions. The PCM applies ground to fire the injector. There has been a fair amount of trouble with poor connections at the injector connector. You might be able to tighten the terminal, if not you'll need to replace the connector, they are available at most auto parts stores.

Another test you can do, to find out if an intermittent loss of fuel pressure is causing the stall, is connect the fuel pressure tester and drive it. At the instant it stalls, if pressure remains above ~45psi, the problem is not a loss of fuel pressure. If pressure drops and then the engine stalls, you're looking at a fuel delivery system problem.

Couple of other things:
Regulated fuel pressure spec for your CMFI engine is 55psi to 61psi. At 65psi you can expect a rich fuel mixture, reduced fuel mileage, and possibly rich O2 sensor DTC's. The regulator can be serviced seperately from the spider.

If the crankshaft position sensor and or timing cover are moved, removed, replaced, or disturbed in any way, the crankshaft position sensor relearn MUST be performed. Replacing the PCM also requires the relearn.

If the distributor is moved, removed, replaced, or disturbed in any way, camshaft retard must be checked and adjusted if necessary. It is part of the job, just like setting ignition timing was on older vehicles.

Both procedures are performed with a capable scan tool, and the El cheapo $500 jobbies at the auto parts store won't do it. Your vehicle has a transition OBD computer control system. It is inbetween ODBI and OBDII. It has its own unique communication protocol. This can be a problem when you have the relearn and cam retard done. Many high dollar scanners do not have the software necessary to communicate with your system. Check with them first.