93 Z28 no start

[Jerry93Z]

Ok, I bought this '93 Z28 for $800. I knew that with a price like that I was in for some serious wrenching.

Car had no ECM, it was missing two injectors, no battery and had about 7 gal. Of bad gas in the tank.

I bought a computer off of the forum ( did not get it programmed to my car)

Pulled two plugs from a B-body (same spray???)

Dropped the tank and cleaned it.

Battery

Replaced all fuses

Pulled fuel lines and "primed" them.

She will turn and the starter is working 1/5 times...the other time it makes the same noise as it would if the battery was dead.

Could the injectors be gummed up?

Fuel pump works but maybe gummed up a little to throw the pressure off?

I will pull a plug in a couple days and see about the spark. What else should I do??? Service engine light is on but so is the "check gauges" light, and my speedo is at 140.

Please give me your thoughts on this, thanks in advance.

[firebird_1995]

Im completely shooting from the hip on this one but was there a b-body that came with obd1? I thought they were all obd2...

[95ImpySS]

Man than thing sounds messed up. I would try and make sure that the PCM is tuned for your car. Or at least close to the specs of your car. From the way it sounds, you may have bad connections. Grounds and positive termial. Make sure the wires going to the starter are tight and corrosion free.

As for B Body's there is a chance you grabbed the wrong injectors. They came with a 4.3l (L99) and a 5.7l (LT1). They look IDENTICAL from the outside. Only way to tell is to look at the back of the block or read the VIN number. P in the 8th digit stands for LT1 and a W in the 8th digit stands for L99. Now, the L99 had 19lb injectors, the LT1's had 24lb injectors. IIRC your 93 has 22lbhr injectors. They will work but the fueling will be off.

Best thing your can do at this point is check your connections, check for spark, and check for injector pulse.

[95ImpySS]

Im completely shooting from the hip on this one but was there a b-body that came with obd1? I thought they were all obd2...

94-95 had ODB1, 96 was the only year they had ODB2

[Jerry93Z]

The ECM was from a 93 F-body bone stock (except for the elbow) the miles were a little higher than mine but other than that it was the same.

What is the best way to check if the injectors are spraying?

I am going to check all connections and pull a plug tomorrow (hopefully) but I do not know how to check if the injectors are good.

[SeanMac]

Unbolt the fuel rails and pull the whole assembly up with the injectors attached. Turn it over.

If you have access to fuel pressure gauge and a noid light u might want to check those and spark first but idk.

[95ImpySS]

As SeanMac said, I would recommend checking fuel pressure as well but you can check for spark and injector pluse without the purchase of a fuel pressure gauge.

You can check spark by carefully using a screw driver inside a disconnected plug wire. Bring it close to the exh manifold (or another metal part of the engine) and look for a spark to jump the gap. Keep the gap small. .030"-.080".

You can check for injector pulse as SeanMac said or you can listen to the "click" the injector makes when it opens. A noid light is the preferred method but all mentioned ways will work. Have some one crank the car over. Then use a screw driver (handle to your ear, tip on the injector) or a stethoscope to listen to the injectors for a loud click. This method is less work and less messy/dangerous.

From your description of what the gauge cluster does you may have a faulty PCM.

I would check your wire connections before doing much more trouble shooting. A bad ground/connection can cause all of your symptoms.

[Jerry93Z]

Ok guys, its been determined that I am not getting spark, going to check all connections and throw a test light around today. Will let you know what I run into.

[Some_Random_Guy]

No spark? All I can think of is plugs, wires, coil, the dreaded opti, I could be missing something

[Jerry93Z]

I am going to start from the begging first; fuses, wires/grounds(from battery), test light on the coil, test light on the opti, then plug wires.

If the fuses are good, the coil is getting power and the opti is getting power but the plug wires are good-then it's something in the opti. If the anything along the check list is crap, it's getting replaced, until this thing gets spark.

Please let me know if I am missing anything to check.

[95ImpySS]

Check if you have injector pulse. A failing opti can also cause the injectors to not pulse.

[Some_Random_Guy]

I know everybody is throwing a ton of ideas at you right now. But remember the FAST rule

Fuel
Air
Spark
Timing