The other day I was checking the timing on my 88 ranger, because its been pinging a little bit.. with the SPOUT disconnected it's at 10 degrees... but when I reconnect the SPOUT, and start it up.. the timing is way over 10 degrees like in the 20+ BTDC range.. is this normal? I tried switching to mid-grade gas and it has helped some.. but it's still pinging.. and it isn't showing any signs of running too hot..

 

The timing is correct. When reinstalling the spout, the computer will advance the timing to where it should be, 25* plus, maybe.

To avoid pinging, don't lug the engine. These are small engines, and like rpm, especially on the heavier vehicles such as 4x4's.

If there is carbon build-up in the combustion chambers from lugging the engine or whatever, you can clean them out with water. Start the engine, rev the engine so it doesn't die, and slowly pour about 10 oz., or so thru the intake system. You will see tons of white smoke coming out the xhaust from the steam. Normal.

Once you have given it a steam bath, take it down the road and run it thru the gears to max rpm before shifting. This will clear out the exhast system, and get rid of any carbon in the combustion chambers that have been broken loose by the steam.

If it is a high mileage engine, the pinging could be the result of blowby. jd

 

Jim is right... Advance timing depend on engine load and RPM, so ususally we have +20-30 dgr. Why PIP is 10 dgr after TDC.... to give ECU ability in case of pinging make timing "later" then TDC to avoid nock....

 

On your vintage ride many things or combination of things, could cause engine ping & vacuum leaks should also be on your suspect list imo.

So all vacuum using systems lines, tubing, hoses, diaphragms, fittings & gaskets need to be checked out.

This would include the PCV valve & hoses, vapor recovery system, EGR system, Brake Booster, hi-vac system & intake manafold.

Other things that belong on your suspect list.
Wrong heat range spark plugs.
Bad gas.
Clogged air, or fuel filters, or a dirty MAF sensor or fuel injectors, that can mess with the air/fuel ratio.

On decarboning the engine, I'd maybe consider adding a good fuel system & engine cleaner-upper like Chevrons Techron Concentrate Plus, to a tank of Chevron, Texaco, or CalTex gas & run most of the treated tank out, while doing some spirited accelerations & highway driving of say 10 miles out & back. BTW Advance Auto has had a two for one deal on Techron lately.

I agree that carbon is a good possibility too, so if you decide to do the water decarb proceedue, be careful not to give it too much to quick & hydrolock the engine & bend something up!!!! Also consider doing it just before a oil & filter change, so you get all the left over putrids & water out of your lube.

More thoughts for pondering, let us know how it goes.

 

hi and sorry for the late reply..I found out that it is not the truck's fault.. it is the way i'm shifting/driving it..I drive a tractor/trailer, and am used to making it grunt.. I guess after i've been in the rig all day I try to make the ranger do the same.. i've noticed if I keep the RPMS up like mentioned earlier it doesn't knock.. i ran some seafoam in it, the last time I changed the oil..so carbon shouldn't be a problem. and like I said earlier the mid-grade gas has helped some.. it seems to run a lot better on it..little bit more power..