Wyatt Bowen

So recently my old ford 302 in my 1990 f150 with who knows how many miles and 5 speed 4x4 died on me and rather than put a junk yard engine i bought a brand new reman from the dealer and from top to bottom its new except for the distributor before the new motor it spark knocked no mater what distributor was put in it same with the new motor it's driving me crazy as to what it could be and I don't want to break another motor due to spark knock any advice on what it could be
I'm starting to think the platinum plugs might be the issue could someone let me know if I'm on the right track thanks

wde3477

Welcome to the site!

Not a fan of all the specialty plugs offered, suggest to stick with the OEM-type Motorcraft copper-cores, gapped to spec.

Without further info on make, model, year, mods - assuming that all else is stock. Suggest knocking is due to either timing, poor fuel, or combustion chamber buildup. Being a new engine eliminates buildup, leaving timing and fuel quality as leading suspects.

Good luck, and keep us posted.

justintendo

need to check and verify ignition timing

Wyatt Bowen

the plugs are motorcraft platinum and timing is dead on I'm probably gonna start with the plugs my next thing it could be is ecm all sensors are either new or tested ok I'm at a loss as what to do next

Wyatt Bowen

we have checked and rechecked the timing and the distributor is almost brand new

Wyatt Bowen

wde3477

Perhaps verify that the timing controls are doing their thing - that is, make sure the timing advances as RPMs are slowly increased.

Wyatt Bowen

thanks for the advice if timing doesnt advance or retard what would be the culprit

dodgeman1

I'm a little vague on how the timing is controlled on your engine. Does it have a computer that controls the timing? Is it controlled by the distributor? If its controlled by the distributor, check inside of it to make sure the springs and weights are working correctly. Without more info I'd say you are getting to much timing advance. You can dial back the intial timing to see if that helps. On an older car I once put a timing tape on it. This lets you see how the advance kicks in as you rev the engine up using a timing light. Somewhere around 30 degrees or a little more should be the max the timing advances. A real lean condition can also cause spark knock. If the timing isn't advancing, I'd say its almost impossible for you to have spark knock unless you have crazy high compression.

Another question, are you sure its spark knock?

Wyatt Bowen

it is computer controlled there is a little computer on the side of distributor and I haven't played with time yet it is for sure spark knock I'll check that when I get a chance thanks for the advice