I have a 1988 F350 EFI 460 and i cant get it to stop pinging. It runs fine at idle, and fine slowly reving it up but when giving it throttle or under load you can hear it pinging. I think it might be timing related. I scanned all the codes, found out my ECT was bad, replaced that, left battery unhooked a half hour.

I timed it to 12* BTDC without the jumper(the two prong jumper on the wire coming from the distributor) and when the engine would rev to about 3000rpm it would go to over 40* BTDC so i retimed it with the jumper to about 13* BTDC and when reving it would go to about 32* BTDC. Before i ran it at 12* without the jumper and it still pings.

The truck runs 93 octane, has new plugs, wires, cap rotor, thermostat, ECT, exhaust is cut off after the Y, stock air box, otherwise stock engine. Oil pressure is right between the N and O, temp gauge doesnt work but i hooked up a mechanical temp gauge and it stays right around 195. Doesnt overheat even during offroading.

So my question is why is this engine still pinging? It pinged when i bought it, its been hydrolocked twice since then and still runs the same still pings the same.

It idles fine.
It holds and rpm fine.
It slowly revs fine.
It cruises fine.

It pings when revving
It pings underload (50% or more)

Could it be

Bad ignition module?
Bad computer?
O2 sensor?
Crank sensor?
Bent pushrod?
Missadjusted rockers?

I really want to get this fixed as it's going to be my work truck and needs to tow 8-14klb daily and it cant be pinging like it is.

Maybe I'm not hearing ping? it sounds almost like a light knock but no knock or tap is present at idle.

Sorry its so long guys i just wanted to try to provide as much information as possible.

Thanks,

Shawn

 

I just found a torn EGR vac elbow (The rubber one coming out of the EGR valve) and then i traced it around and found that where the green vac line (one from EGR) connects at the solenoid (The EGR vacuum regulator) had the bottome broken off of it. Do you think this could be causing my pinging? Also where can i order the vacuum regulator and about how much are they?

Thanks,

Shawn

 

It probably has carbon build up on one of the valves or it could be on top of the piston. Mine did that too before I rebuilt it. But it could be other things that you listed as well.

 

If it suspected carbon buildup, warm up engine, get your water sprayer out and spray water into the intake as you rev it up. This will knock of the carbon deposits in the combustion chamber.

 

I don't think it's carbon build up as it's had plenty of water through the intake and twice to the point of hydrolock. Engine has 90,100 miles on it, plus I sea foamed it when i first got it. Didnt smoke much at all. Seafoam is a much more efficient way of breaking off carbon deposits imo.

So why does my timing advance so much? Could the broken EGR vacuum regulator be the problem? I also found a couple connectors that are undone, but cant find where they go and alot of vacuum T nipples are capped off as if there were more things that needed to be hooked in. Is that normal?

 

I dont know why you are getting so much timing, but that definitely sounds like the issue. Get the timing to normal limits and you shouldnt have to run 93 octane.

 

Well with the spout off and total timing of 12 degress it still pings so it leads me to believe its something else. I'm going for EGR vacuum regulator as it was found broken. Its thinking the EGR vavle is opening up, leaning out the fuel, and then causing it to pin from being so lean. That's my guess as I'm not getting an EGR code so it must think its working properly.

 

An EGR really shouldn't cause a ping.

 

I'm going to try cleaning the IAC today, also to check fuel pressure as i think maybe the fuel pressure regulator is bad.