Trying to help a buddy out with his truck, and I need to borrow it for the weekend as well.

89 F250, 2WD, 5.8, manual, all stock, emissions systems intact.

It pings, in any gear, with anything more than 1/4 throttle, horribly.

I ran emissions on it today, and while it stunk, it passed with flying colors.

Pulled the codes and got 33, 87, 95. EGR and fuel stuff, only runs off the front pump.

I went to the EGR, tried the trick to drop a penny in it to temporarily block it, and of course the tube broke. So tomorrow I am going to try and block it off at the manifold for temporary with a quarter while I wait for the tube, and run it blocked at the EGR with a penny. This will bypass the EGR as well to rule it out.

Also, fixed two vacuum leaks.

Still pings horribly.

I did notice all the spark plug wires were together, and read that can cause issues.

Anything I should be looking for here?

 

Check the timing.

Base timing is 10deg but the spout plug has to be removed to disable computer advance before setting it, the spout is a little grey plug in the wiring harness hanging of the distributor.

 

So unplug and do 10 degrees at idle?

 

Yes that's right.

 

Timing was 20 degrees off. It runs about the same, and the noise did not change.

It really sounds like it is coming from the right side of the engine only, I wonder if it is a piston slap.

This truck leaks oil like the Exxon Valdez, there is a chance it got run low and has been "pinging" for a long time.

The noise is really quick, and very metallic, it is much too fast to be a rod knock. Only makes the noise under load, worse when you are in too high of a gear and punch it.

 

It can be worth a shot to try cleaning the upper intake and the throttle body to remove deposits and carbon build up. Did you try running a higher octane fuel? If you still have noise with premium/super, the correct timing, correct plugs, a functioning (not clogged) cat, and no carbon build up you may have internal mechanical problems.

Disabling the EGR can actually make the situation worse, since it's function is to dilute the intake charge to cool it during cruise (thereby lowering NOx emissions). Detonation can be caused by too much timing, hot spots in the combustion chamber, a lean condition, high operating/intake temperatures, and lugging the engine.

With correctly functioning emissions control equipment the truck shouldn't "stink", in fact it's the catless ones that will make your eyes water. You may have a partially melted/clogged cat.

 

It got premium in it this morning, we have had to run premium in it for years. This is the loudest I had ever heard it.

To clean the intake are you talking pull the upper manifold? I assume there are passages all throughout it. Same with the TB, just pull it, soak it and wire clean it out?

That is a bit of work .

What about the plug wires? They are all zip tied together.

 

Check the spark plug wire boots at the plugs. Mine was arcing to ground thru the boots making a sound like you're describing. New wires and plugs took care of that problem.

 

You need to get those plug wires separated. Especially the ones for adjacent firing cylinders. Some info from Steve83: 1983 Ford Bronco TSBs & FSAs (Recalls) for '83-96 Broncos & F150s picture | SuperMotors.net

 

Correct, if the plug wires must cross they have to be at an angle, if they're parallel it will induce a cross-fire situation. One of the easiest ways to clean the intake is to run some Seafoam or ATF through the brake booster hose while the truck is idling, (go easy here, add just enough so it begins to stumble) and shut the truck off, allowing it to soak. Wait 10-15 minutes, start it up and drive it hard to clean out the deposits.

To clean the TB, pick up a can of TB cleaner and a soft toothbrush. Take the intake tubing off, and prop the throttle open. Clean both sides of the throttle plates and the bore itself, you'll be surprised how much crud builds up.

 

I'd do a compression test. If it's been pinging for a long time, there's a good chance your pistons are toast.

Jason

 

Thanks for the replies.

I am heading out of the country on Tuesday, when I get back I will seafoam the manifold and the tank for the injectors. Also, the wires look like junk, I will replace them with OE and loom them correctly.

I wonder if I should just pull the upper and lower manifolds and be done with it, the valve covers are leaking badly, may just be smart to tear it down and verify everything is sealed up, but not if the motor is junk.

Maybe pull the air system off to clean it up and get rid of potential leaks.

Also, I am not sure I hear two fuel pumps running, need to check fuel pressure.

Thanks