Hello, out of the blue my 302 has started to ping. I have had the same set-up and tune for 4 years with no problem. I went to work on Thursday and when I left for home it started to ping as soon as got gas. So I figured it was a bad tank. On Friday I did a few thing. 1. new plugs gap at .35 auto-lights #45 2. change power valve, had 3.5 for better gas mileage, went to 8.5. 3. change the cap and rotor on my Pertronix Ignite. Also lube my weights 4. pulled my timing back from 13 to 10. 5. Went I went to adjust the idle mixture screws using a vacuum gauge I notice a small fluctuation of 1 to 2 deg at 16 deg. Normal reading is a solid 16.5. Saturday went to Shelby get together at the Peterson . About 120 miles round trip. No change, it only pings on take off,even normal take off. On the freeway I pulled it down to about 50 mph in second gear and put it to the wood. No pinging. I put some move HI-Test gas with no change. It still pings on normal take off. That is the only gas I have ever used is Hi-test. I have had the Mav for about 12 years. In all that time it has never ping. I need some help on this.
i would guess that tank of gas was bad. i would suggest putting some octane booster in the tank. oil contamination can cause detonation. if your pcv valve is bad it could be sucking in some oil. or it could be leaking valve seals.
Hello, thanks for the info. My normal gap with the Pertronix Ignite II has been .44. I will check the PVC tomorrow. Thanks Tony
are you positive(an oil pressure guage?) that it's not the lifters clattering away at low rpm? Otherwise.. I'd also go along with the others on the "bad gas" theory. Especially since I normally run 30 degrees or more initial timing(combined with vacuum assist) at idle rpms without issue.
Hello, my oil pressure range is 15(190-200 temp at idle)-60 psi, temp is between 180- 200. I have a 180 t in it. .I run the tank as low as I can, Then I will run some 76 Hi-Test (91 in calif) and see what happens. The Mav has been my daily driver for over 4 years since I change the cam , I have had the Mav since 2006. Have a great Maverick day Tony
Just because you think you bought premium fuel doesn't always mean that's what you got. Some fuel driver could have had too much regular fuel on the truck and instead of taking it back to the rack, he could have dumped it into the premium tank. (yea, I used to haul fuel:evilsmile) Run that tank out and get a new tankful at a different station.
if 15 PSI idle pressure isn't any different than it used to be?.. then I would have to agree with all the rest. You got some crappy gas and your initial ignition lead setting ain't too happy about it.
Hello, I have run 3 tanks of gas. The pining is still there. 1. I just notice I have a lot of blow-by at idle 2. My oil pressure has been 15 psi at idle since day one . 3. I up my power valve to 8.5 4. I up my jets from 65-68 5. I put the heavy springs on my dizzy weights. No change. with the blow-by and fluctuate 2 1/2 lbs at idle. 16.5 lbs at a 1000 RPM. Do you think I have a build up on top of my pistons causing pre-ignition ? Thanks for your help. Still driving the MAV, with a very light foot Tony
Frank, that's what I was going to say. My first build in a machine shop on my 302 . I had to adjust my rockers after the install , because of my cam that I used.
15 psi at idle is kinda low,I`d be happier if it was 25.Sounds like another possibility could be your timing chain has stretched a little w/ some wear,retarding your camshaft on initial idle off causing the mtr to lug.This would make it ping especially if the mtr has a lot of miles on it.Once you get up to speed it would not do it.
Hello, thanks for the info everybody. I put a dial back timing light on it. WOW at 2000 RPM I have 55 deg total. Something is wrong with my Pertronix dizzy. I will take it to pertronix on Tues and see what up. Went a great car show at Sunnymead buggers in Moreno Valley and my good friend Gerry with his 65 fastback. Thanks Tony
