[Vistablue08]

First off this is a buddies car bought from a used car dealership with the swap already done. It was a hack job that I am fixing multiple issues with,

Here are the particulars

2000 Gt 5-spd
Stock GTG3 processor
19 # Injectors
4v coil packs
No egr
No delta pressure feedback sensor
Stock mass air
Stock tune


Was brought to me as a no start condition, with no spark. Used my OTC gensis scanner and found a bad pcm, at the same time I found 5 different wires that were extended and spliced with wire nuts, crimp connectors, bare wire and electrical tape. I removed the engine harness and correctly soldiered each of the wires and connections and reinstalled it. I installed a reman processor from Ford and had them reset the pats system. The car now has spark, has fuel, but still wont start, it back fires intermittently through the throttle body. All of the connected sensors are showing proper voltages when I datastream it on the scanner. I went through a did a compression check and all of the cylinders are in between 185-195 pounds.

What am I missing??? It is acting like it is out of time but with the injectors and the plugs firing( and in the proper order) and the compresion being equal on both sides (broken timing or improper cam timing) I am at a loss.

Any input would be greatly appreciated


Thank you!!!

Adam

 

[oxfordgt]

You cant use that computer with 4v coil packs. You either need the computer that drives that kind of ignition or get the GT computer tuned to run them.

 

[Vistablue08]

Can you explain further? I read that the difference between the 2v and 4v coil packs was a B+ engraving on the coil pack that is for the 12v reference voltage , and you just have to switch the wires to have the polarity correct. Is this true or do I need a custom tune just to get it started.?

Thanks for the help!

 

[oxfordgt]

Tell me more about the aviator motor. Not really sure what it is. is it a 2v 0r 4v? what size is the engine?

 

[Bullitt1992]

Weird. Subsribing as I will be doing a 4v swap. 2v COPS and 4v COPS are reverse polarity (is that the right usage?)

 

[1badgt]

Tell me more about the aviator motor. Not really sure what it is. is it a 2v 0r 4v? what size is the engine?

Its out of a Lincoln Aviator, hence 'aviator motor'. They are 4 valves too. OP, there are a bunch of threads of a 4v swap. You can double check the work done to that of the writeup. If I have time I will dig one up for you.

 

[limited]

sounds like your not getting the spark at the correct time,should have no intake backfiring. what do the plugs look like?
what firing voltages (kv)are you seeing during crank?

 

[bad N/A 2V]

What ended up being the problem. I just finished swapping a 4v into my 2000 GT, and I am having the exact same problem.

 

[steele6599]

Just a thought would it be realted to the security in the PCM and the chipped keys? I thought you can disable this via a programmer...

 

[NeverEnuff]

a GT computer can run 4V cops fine. They are the same, minus the swtiched polarity. That info is wrong.

If he is using the same coded PCM, he doesn't need anything chipped or reprogramed. If the computer is good, and it starts but dies and backfires, my first suspition would be the wiring. It was a hack job...so I bet your problem is there. Worse case...get a new replacement from Ford. Not that expensive. I just paid 170ish for the main engine harness. If the wiring is good and you know that for a fact...then you need to make sure the motor wasn't messed with. My bet though if you are getting spark and it tried to start, then they probably messed up the wiring with the COPs. They probably messed up cyls or something like that.