I have a 95 blazer, 4.3, sometime it's a no start. When I do get it started, take it for a test drive, starts running rough and stalls. Then it's a no start. When it will not start it has fuel pressure (60psi) and spark (via HEI spark tester). With the key in the on position there is not 12v going to the fuel injector, tested at the injector connecter with a test light. Test light connected to ground and probing the purple wire. What would cause a loss of the 12v going to the injector?

 

1995 was a hodge podge year that used 2 different computer control systems. On the RPO code sticker in the glove box, there are several 3 character codes. We need to know which engine code is on the sticker: "L35" or "LB4".

 

L35 is what's on the sticker. It has OBD2 if that's any help.

 

It's actually OBD1.5 and will provide "P" codes for diagnosis. It's a "crossover" system from OBD1 but it only has one fuel injector, and is not fully OBD2 compliant.

Are there any DTC's in the memory, history, or pending files? If so, what are they, and what order were they retrieved?

When it will not start: With the ignition in the RUN position, is there battery voltage on the pink wire at the ignition control module and ignition coil?

 

I don't have access to a scan tool, so it's unknown if there are any DTC's stored.

I'm replacing the gear on the end of the distributor right now, so I don't know if it will not start or not. With the key in "run" position, test lite shows voltage at both pink wires for the ig mod and coil. Still no voltage at the purple wire that connects to the fuel injector. I assume there is to be voltage at the purple wire in "run".

 

Keep in mind that when EDI distributors are reinstalled, camshaft retard must be checked, (and adjusted if necessary), with a scan tool capable of accessing the data stream. Incorrect adjustment can cause premature distributor cap and drive gear failure, misfire, poor mileage, and in extreme case, a no start condition.

The red injector wire should have battery with the ignition in the RUN position. The PCM supplies a pulsed ground to open the injector. There's a fairly common problem with the wires not making good contact at or near the connector. Remove the fuse and use an ohm meter to check resistance from the injector connector to the fuse terminal. Resistance must be less than 5 ohms.

 

I'm sorry for not being prepared to work on my Blazer. I thought I had an S-10 book around here but cannot find it. I've looked at the fuse panel in the dash by the driver door. The injector fuse is not labeled as so. I see three fuse that could be a possibility, 1) ECM (BATT), 2) ECM (IGN), 3) ENG-1. Unless there is another fuse block I don't see somewhere.

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I pulled out the fuse marked ECM (BATT) and check with an ohm meter from there with no results. I don't know if that is the correct location to check. Is there anything else on that circuit besides the injector, just to see if 12v is present.

 

In the instrument panel fuse box, Fuse #10, ECM/IGN, 20 amp fuse, feeds the pink wire that goes to the injector. It must have battery voltage with the ignition in the START and RUN positions. It also feeds the PCM and the canister purge solenoid, (right side of plenum, near the ignition coil). Post your results.

 

Canister purge pink wire has 0.92 ohms from the fuse block, injector purple wire has no reading. The wire looks purple to me, could it be on a different circuit? If it is on the same circuit then I'm probably looking a broken wire somewhere?

 

Canister purge wire is fine if it shows battery voltage in RUN and START positions. If that's the case, the injector wire is open, and that's the problem. It splices to the same wire that goes to the canister purge solenoid inside the harness. Not necsssarily the best way to fix it, but the easiest is to run a jumper from the pink wire at the canister purge solenoid, to the injector feed wire, which originally was pink, but has probably faded.