Hey guys,
I have been pinging since I have been rolling again (3-4 months). I have tried different Coils (had some laying around, Stock and MSD 8227), replaced coolant sensor (checked with meter and was bad), replaced ACT sensor (old one was carbon-caked), new 02 Sensor, 2 oil changes, 2 new sets of wires (BOSCH 8mm and now Accel 8.5mm), 2 new sets of spark plugs (tried .044, .050, .054 and side gapped at .054), new coil and rotor (had to replace distrib. when it first started driving again, new cap\rotor came with it), cleaned EGR and checked tube that goes under intake, but I can't see it all that well. When I was figuring out the distributor problem I cleaned the injectors, replaced fuel filter, and replaced fuel pump (low pressure, and replaced strainers), and 2 seafoam treatments.
I'm at a loss right now, I don't have a vacuum gauge, but I will be getting one tomorrow so I can set timing by something other than the harmonic balancer. Oh and the spark plug wires are run right, I have redone them many times just to make sure they are EXACTLY like the TSB. Also to make sure there is no cross firing I unplugged all lights and revved it in the dark, no sparks.

Ideas? You will be my hero if you can help lol

 

Very little if any of that affects pre-ignition.
What engine?
Where is your base timing set?
Does an 89 have a knock sensor?
I've never used Seafoam, is it a carbon shaker?

 

Oops, I guess my new Sig didn't show up yet. It should be there now, if not I'll edit this...
I've tried it at 14, 12, 10, and 8 (yes, all had the stout pulled). One thing that was weird is that when I switched abck to the stock coil, it changed my timing, I did nothing else but switch the coil when it was at 10BTDC and with the stock coil it dropped to are 3-5 BTDC. I retime it back to 10btdc and it pings waaay worse than with the msd. Just to check, I left the stout unplugged and wen taround the block, not a sing ping (but having it retarded 8-10 degrees would do that lol), so I know it's timing related. I'm really wondering if my harmonic balancer walked on me, it has sat for awhile, but only has 68,000 mles on it.

It does have a Knock sensor and i tested it with the hammer trick, I have it hit it somewhat hard (not a full swing or anything, but yea), and it did retard the timing when I hit it.

Seafoam is one of those one can does it all that actually works, you can put 1/3 in the gas tank, 1/3 in the crank case (500 miles before oil change), and 1/3 through the brake booster (except on mine cuz my brake booster\pcv hoses have been switched). When you put it through the brake booster you shut the engine off when your done and wait for about 10-20 min, then start it back up and burns all the carbon off....lots of smoke. My truck hasn't smoked all that much from it, but enough for me to know it's working.

 

If you have a knock sensor and it is working, what you hear as pinging could be something else. Knock sensors are supposed to pull out timing and make the pinging go away. Of course if your base timing is advanced too far, the sensor cannot overcome that.

Does your damper pulley have marks for both TDC and 10° BTDC so that the engine can be timed with either a conventional timing light or a dial-back? Are you sure you are using the right mark? If your base timing is at 20° BTDC, that would explain the problem and also why the knock sensor cannot fix it.

If that doesn't work, you need to find TDC independent of the markings on the damper pulley

 

My damper has 10....0.....10...12btdc, and I have sanded\marked 10, 14, and 20 (just for reference, and when I check the knock sensor, etc.). My timing light is old school, just a blinking light, no ***** or anything. Of course I check the timing many times, including after I tighten the distributor. I have tried finding TDC with the old screwdriver in the #1 spark plug hole technique, but the problem is that the screw driver gets pinched, so I can't find EXACTLY where TDC is, only a general area. With how much is pings, I figure the damper is off (if it even is) by only a few (5-10 max) degrees. When I have it at 10*, with side gapped, and the MSD coil in, I can barely get it to ping on level ground (1-3 pings heard), but when I go uphill it's a different story (too many to count).

I was wondering if there is a way to see if the Damper has walked by comparing the holes\marks on the inner part of the Damper. For example, one of the drilled holes would line up with 0* TDC or something along those lines.

 

Why don't you just time it by ear? Retard it 2 degrees at a time till it shuts up. Your other option is use high octane gas.

 

I'm doin that to get by, but if it's not running correctly at stock settings, then something is wrong. I want this thing to run the best it possibly can so I can get the most HP\MPG out of it, so the less that's broke, the better.

Checked EVP sensor just to be sure, and it's right where it should be. My TPS is at .97v when it's cold and 1.00 when it's warm, but I doubt something that small would cause anything like this.

 

Now I'm confused, I changed nothing but the coil to the MSD and it advances ~8 degrees, how is that possible, the Dist is not changed, and its happened more than one time. If I switch back to the stock coil then it reverts back to the original 10 BTDC, if I time it down to 10BTDC with the MSD on and THEN switch back to stock, it's at 2 BTDC. Either way it pings at 10 BTDC, I just have to retime it when I switch the coils for some reason. Still pings....!!!!!!

 

Well, just an update, I remote mounted the ICM (didn't seem to make a change), set the timing with a vacuum gauge, and my balancer is DEAD on. The pinging got progressively worse, to the point where it did it in Park. I pulled KOER, and got code 41 (KOEO and CM were code 11), having just replaced the HEGO, I got under the truck and checked ground\+12v, etc. Of course the wiring checked out fine, but I noticed my valve covers were leaking. Finally, something I can fix. While I pulled it all apart, my TAD vacuum line broke at the solenoid and at the diverter valve itself, so I decided to change the vacuum system(MAP, EGR\EVP, TAD, TAB, Canister, FPR) to rubber hose(25+ feet later...). Also while I was in there I bought myself a set of explorer injectors (what a steal at $30 for 8 w/pigtail), cleaned them and swapped them in (direct swap yay). I cleaned EVERYTHING, even sanded most of the metal that bolted together so they would make a good connection on grounds, hell I even ran extra grounds.

All of this was done at the sametime so I'm not 100% sure of where the problem was, but the end result is the same. IT'S FIXED, and man does it run good. Not pinging at ALL, idles smooth, has way more low end, etc. All I have left to do is double check timing (never took the distributor out so that shouldn't have changed) and run KOER one more time to see if the 41 goes away (I'll check KOEO and CM, just to be sure, even though it's been started 3 times).

If anyone wants the whole story here ya go, it has pics of the Remote ICM (XBOX 360 heatsink haha), and all that jazz.
http://fullsizebronco.com/forum/show...=186507&page=3