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96 Pontiac GranAm 3.1 cranks but no spark

I replaced engine block because original broke the cam shaft and scored the bearing surfaces as well as crankshaft bearings etc. We rebored a junk yard Regal 3.1 block and fit oversized bearings for the new camshaft as well as replaced bearings for the crankshaft and added a new crankshaft plus usual homed cylinders, rings ect were indicated. Used the original heads after the usual valve reseatings and lifter replacemants where needed. We meticiously marked and taped all wire connectors, vac hoses, motor mounts and various lines as well as numerous digital pictures of “before original engine dismantling” and removal etc to guide reinstallation.

Reinstalled rebuilt engine without difficulty and rehooked up all lines and wire harneses with no leftovers.

As we rehooked up the battery as final act before cranking, noted that yellow park lights were on without key being inserted at cylinder. With or without key inserted and testing all switches lights will not turn off. Turn signals, hazard lights, headlights all function on proper command. With key in the on position, also note that the “check engine” and trouble lights cluster do not respond.

Engine will crank with start postion of key, but we get no spark.


1. Could a faulty crank shaft sensor (two with this block, one at harmonic balancer and other behind the block) or the camshaft position sensor account for all these symptoms?

2. Where could we have a short which would account for all these symptoms?

3. Could a faulty relay be the cause?

4. In addition to no ignition coil spark, we do not detect the fuel pump operating by sound nor is there any smell of gas at the cylinders. We did try both ether as well as spark light tester to confirm no spark.

5. Would a miss on the timing chain allignment account for all of these synmptoms?

We need help and can not afford the dealer route or mechanic shop route since we are reasonable shade tree mechanics plus one very experienced engine rebuilder.

Thank You

Check to see if the ‘Check Engine’ bulb is blown. If the CEL does not light up for a couple of seconds when the key is first turned on indicating the ECM ‘self-test’, there is a problem with the ECM. Either it is not getting power, or there is another critical fault. The ECM controls both the spark and fuel pump power through the relay. No ECM, no spark, and no fuel pressure.

BustedKnuckles: Thanks, the entire cluster of trouble lights do not come on to include the CLE, ABS, and all the others. Big question is why are the park lights on with or with out the key in the cylinder as long as the battery is connected? Only way to turn it off is to disconnect the battery. Apprecitate any suggestions. Has anyone tried “Ask a Mechanic Now” and how costly is it?

If you have an alarm system installed you may need to reset it using the keyfob. If that isn’t the trouble then you most likely need to see if power is getting to the ignition system. Since the warning lights are also not turning on you need to find out if power is getting to them also. They make the ground connection through the alternator lamp circuit. Check all the fuses and fusible links.

I am wondering if you might have a ground problem i.e. the ground between the chassis and the engine. Hope that is all it is.