Hey all,

Ok so i got about 2500 on my full rebuild and i've had a few little issues, but nothing to serious till this. I find when i drive on the highway at like 60mph in 4th and or 5th gear under any load starts to ping, it doesn't do it around town.
I checked the timing and it's good at 5* - oil is fine - plugs are good gap is fine. I'm stumped!! Any input would be great thanks!!

 

EGR system working properly?

 

Ya i think so. it's all hooked up. Runs fine otherwise just highway pre ignition dunno what the deal is... Any other ideas Abe i know you got a solution for me

 

What octane you using ?
If your using 87 or 89, have you tried higher?
I see your running a custom cam on your 22re is this the motor that's pinging?

 

Could one affect that bye richening it up via the AFM?

 

Incorrect fuel grade? Egr faulty?(Disconnect vac line to it and drive) Idle Set properly? Plugs and wires good and OEM or NGK?(If you got a cheap set in there thats prolly why) Valves adjusted properly?

 

Yes all the above solutions have been checked. Running ngk plugs and wires, 87 and sometimes 89 octane. The weird thing is it just started like 200 miles ago. Everything is to speck, and i'm sure it's not the cam. It's def a pinging pre ignition. I just can't figure out why. I don't want to mess with the mafs if i don't need too. going to try dry gas with 93 or 94 octane to see if it helps. Perhaps the change in climate got some condensation in the tank, dunno.. Thanks for the replies keep em coming...

 

try changing the brand of gas for a tank or two. I changed from exxon to shell and mine stopped pinging.

 

I only use shell always. I'm at a loss been trying to figure it out for 2 weeks. Been so busy never got a chance to post on here till now. Figure if you Jedi can't help then i'm up a creek with a brand new motor..... Well sinking with a 400lb motor lol..

 

I doubt you got any waterin your tank from condensation, it would have had to sit for months with no use for that.

I had the same thing on my old Runner with a 3.0. But it burned almost as much oil as gas, so I knew that's what caused it. I had to run 93 and it wouldn't do it. Only like an extra $3 or $4 to fill up, no big deal.

Are you burning any oil at all? Burning oil will lower the octane rating of the gas and cause pinging/pre-ignition.

Is the 3.0, because isn't correct timing on a 3.0 10*?

 

no it's a 22re. It's burning some oil but that is to be expected from a fresh rebuild with less then 3k on it.

 

Since you've added a high performance cam I'm going to assume its got more lift and duration than stock. Maybe you need to run a few tanks of 93 or try some octane booster and see if it still pings. I see you stated you sometimes run 89 but I'm unclear if you tried 93.
I've got a modified motor in my Runner and there is no way I could run anything under 92 octane.

 

I'm thinking EGR, pull it take a can of carb cleaner to it. A little bottle brush wouldn't be a bad idea also.

Or is it running to lean. What kind of cam are you running. If a performance did you dial up the AFM. Pinging is from preignition, preignition is from heat, higher combustion temps are come from lean fuel/O2 ratio. This is why I sat the EGR to as the reenterance of exhaust fumes is to cool the combustion temps thus reducing NOx. Have you had the pipe gas analysed?

 

Ya I'm running the engbldr 268 cam. got new injectors cleaned up everything when i rebuilt her. i'm going to try to retard the timing a bit and check the plugs. Shouldn't the ecu see that it is leaning out and adjust though? i was told i wouldn't need to mess with the MAFS and it all of sudden started but i don't want to burnout my rings from it happening. I just took a long highway drive after putting 93 in it still does it at 70 3000rpm with the slightest increase in peddle>>> i'm not flooring it just give it a bit more and it pings like a SOB....

 

Is it miss firing? Sounds like your valves may be too tight..... Does it get better with increased timing or decreased?

 

adjust the AFM, what's the big deal? cut the silicon, pop the top off, mark the black wheel for an index, loosen screw, turn wheel counter clockwise 2-5 teeth. Just press the top back on so you can take it off again. Disconnect battery or pull efi fuse for 10 seconds or so. Take it for a spin, If no ping problem solve. Go home clean all the old silicon off and reseal it. Some one told me you needed to do this for a cam, ppl will tell you anything.

 

http://www.lcengineering.com/TechNotes/?techid=11

 

Ya i guess it might be the solution... But why did it start all of a sudden? I need to check on a few other solutions before i go mess with the MAFS.
It's not misfiring at all runs great except for the ping. I'm going to try to retard the timing but if it works to do that should i leave it retarded?

 

what bore is your cylinders?

 

Did you ever solve this problem?
I am having similar issues with a 22R (250k miles) carbed motor at 3k RPM in 4th of 5th gear. Pings worst at part throttle and goes away as throttle is opened further(floored but without secondaries). Lean in the primaries?
I disconnected the EGR with no effect. Possibly carbon build-up in combustion chamber?

Any help is appreciated
Scott