replaced my 3.4 engine in my 03 (out of a 03 impala with only 65k on the engine). with that we also replaced, spark plugs, wires, air filter, ignition module, battery, heater a/c control unit. made sure all wire harnesses lined up and had good prongs, and were making contact. triple checked ground wires. its getting fuel, you can smell it and hear the pump. but we have no spark . i currently have a new ECM on order but my mechanic is arguing that it started the car before we swapped the engine so why wouldn't it now? he insists there's a wire problem. but i was also told last year my ECM was bad by him and the dealership. my security light is not flashing so its not passlock (but that doesn't effect spark anyhow, that disables fuel to the engine) if it was the crank sensors (i have 2 of them) i would think that the ECM would be reading they are bad..but it doesnt bring up any codes.
Is there ANY thing else that maybe we are overlooking that someone else out there has had this same issue or something close that could give us something else to check into? ANYTHING would be of help please

 

I've had a bad crank sensor before with no codes from the PCM, so that could be it

 

well since we still have my old engine we can take the crank sensors off of it and swap them (had spark before the engine swap). i find it odd that an engine with only 65k would have bad crank sensors but hey...ive known gaskets to go at 40k so its worth a shot to give it a try. i guess anything could have happened to the sensor after the car was in its collision, sent to a junk yard, ripped to pieces and moved around lol

 

Autozone will test your Ignition control module for free.

Is the engine turning (starter working?)

The second and thrid page of this guide shows how to test starter, coils and other various things on our engines specifically...
Part 1 -GM 3.1L, 3.4L Index of Articles

You mav have to do a crankcase re-learn procedure with an odb2 tool to try and get the engine insync with the PCM maybe...

Your stock pcm or the impala'a?

 

we tested the ign mod and it wasnt doing anything which is why we bought a new one...but then that still didnt matter anyways.the engine is turning over fine. the dealership didnt say anything about a ECM relearn and i even asked them if it should. they said that as long as it was the same year and we used the majority of our old stuff or new parts it should work fine and they are just as confused as we are as to why we dont have spark. but yet they never seen the car. my original stock ECM is whats still in the Car. i never got the impalas ECM. i had Auto zone order a new ECM preflashed so that all i had to do was plug it in and start her up...My hubby is going to put my crank senors in tomoro from my old engine and see if that makes a difference. if it doesn't start and even after a new ECM the only thing im left with is ignition switch or a wire somewhere...i think anyways....

 

So, do you have a new Ignition control module? (Its the plate that your coils sit on) Also there are 3 plugs for the ICM, make sure they are all plugged in completely.

How did you test for spark? At the end of the wires or at the coils?
The link i posted shows how to test for spark.
Part 1 -GM 3.1L, 3.4L Index of Articles

Also... I just rebuilt my 3.4 and had to disconnect all the fuel lines under the hood. When i went to start it for the first time it would just turn and turn. It took like 45-60 seconds total of cranking to clear the air out of the fuel lines...
Maybe that is the issue and not a spark problem?

 

If the car requires a security re-learn everything works as normal, except the fuel injectors do not fire. So the fuel pump activates, coils send spark, starter cranks, but not a drop of fuel gets sprayed by the injectors.

Smelling fuel can be a bit of a false/positive. As I understand, you really should not smell fuel on a fuel injected car unless there is a leak somewhere. It's a pretty closed system. Now if you're looking for it, keep in mind various parts exposed to fuel are impregnated with the odor. You could be smelling it off those parts.

Plus, if you are spraying fuel but have no spark, you need to be concerned about flooding the cylinders. Has anyone pulled any plugs out? If you have no spark, they should be soaking with fuel after trying to start the car. A good way to check for spark is using a test light that plugs in between a plug and wire (or coil and wire), that will light up when it gets spark. Harbor Freight sells them for like $5-$10.
90º Inline Ignition Spark Checker

 

yeah we bought a new ignition module after he tested for spark and had none, then tested the mod for spark and it was negative as well. all my plugs and wires are new and now so is the module. he has a spark tester. not sure where exactly he tested for spark for i was sitting in the car asking " fire it yet? you ready?, how about now?" lol i was only able to see thru the small gap in the hood. ill have to ask him when he gets home, and ill show him the link you sent me to see if any of it helps him if he didnt already do it the same way. and the plugs were checked like 4x. checked the prongs to make sure none were bent or anything as well. triple checked all fuses. thanks for the link. ill get back to you after i speak with the hubby

 

i want to thank you very much for the site with the trouble shooting. i had my hubby look it over and i read it 2x so i understood it well, and when we hooked the meter up to the crank sensor wire harness and when we would connect the ground it would shut the unit down so we tore the crank sensor out and was going to put the one from my old engine in and he couldnt get the harness to come up. here when he put the exhaust manifold back on it pinched the wires and damaged them. so he took the harness from my old engine and hooked it up and she fired right up!! it was soooooo great to hear her run again!!

 

Thats awesome! im glad it was something simple!