Shop fixed Pre-ignit at computer... uuumm

[gtstang99]

My 4.6 had bad pre-ignit on thrust at around 4500 RPMs.

At At 58,000 Miles, I would say this is probably carbon build-up...right?

A throttle body overhaul, new platnum plugs, injector clean and so on should be the correct fix.

Yesterday I took it to the dealer.. the tech puts it on the computer and says the reason its pinging is because the computer wasn't retarding to the ping, thus was stuck in advanced. So he reflashed the PCM to "Open retard for ignition" as he put on the work order.

It solved the pinging, no problem. The computer is now going through the "learning curve" again which is a pain.

I'm still doing a throttle body clean / plugs / injectors... but has anyone ever heard of pre-ignit being cured like this before?

 

[bdcardinal]

ya it happens all the time with computer controlled ignitions. for the pllugs, dont waste your money on platnium. get some Autolite 764 coppers. they are a lot cheaper and perform just as well if not better than the platniums. plus autolite makes motorcraft so they plugs are identical.

 

[trinity_gt]

Interesting, since the PCM on GTs cannot detect detonation since they don't have knock sensors.