92 ls pinging really bad!!!

our 92 legacy started pinging terribly!!! under load the worst, sounds like a piston about to shoot out, under light accell its fine, and when its cold, same its perfect. knock sensor? theres no cel light or anything, has had new plugs, fuel wires, coil maf, and coolant temp sensors all within the last 10,000kms

What spark plugs do you have? If they're Bosch or domestic, replace them with NGK or Denso.

 

You can also try fuel system cleaner or Seafoam. Also, have you tried higher octane, and if you have, what happens then? Head gasket problems can also cause pinging

Hello;

Knock sensor would be the likely suspect. Also check timing, and the cam/crankshaft sensors. Also check the ecu for stored codes. You may not have a hard fault yet to set off the light but enough for a stored code! Steven.

ngk plugs, number 22401aa310, knock sensor 22060aa031, new ngk wires, new coil 22433aa370, still pinging pretty good under load. no mechanical engine noise whatsoever. very frustrating!! seems to lack power too, fuel consumption also seems high, could a crappy 02 sensor cause this? It has a bwd direct plug in sensor.no codes either

i have seafoamed it, ran it in tank, and tried octane boost with 91 octane, still pings. no sign of headgasket issue, no trace of exhaust oil in coolant, no external leaks.

weak fuel pump. try checking fuel pressure.

alright, will do, dont know why I forget the basics sometimes... I noticed the fuel pump isnt under the seat? drop tank to replace?

Hello;

Pull up the trunk mat and look for a oval cover behind the seat on the right hand side. You can pull the return line and see if there is fuel returning to the tank if you don't have a pressure gauge. I am talking about the one under the hood. Check your cam sensor and knock sensor. Do yourself a favour and go to the only sticky we have for the first generation. Click on notes & tips, then tech articles, look for the FSM (92 manual). Download this, Steven.

pump good, pressure and flow good, trying oem front oxygen sensor tonight, and hopefully some injectors in the next couple days. Also thinking my bigger tires arent helping matters especially in fuel dept, maybe drop back to a 16" 205/55/16

Fuel pump replacement DIY: http://legacygt.com/forums/showthread.php/walbro-255-lph-install-diy-198427.html

Hello;

Pull the front covers and check the timing, could have skipped a tooth somewhere. Steven.

next on my list, it had a new oil pump very recently

Exhaust flow good?

check for stored codes, for sure.

 

You can test the injectors at least to hear them click, but that will not tell you about real flow. I've had WitchHunter clean/flow test several sets of injectors and you'd be amazed how well a car will run with crappy injectors, though.

 

Crank and cam sensors, definitely check.

 

Timing, yep that too. Count your teeth and make sure those cams are lined up right!

fuel pump........ guess it was intermittent, tried to pull a summit and it kept running out of fuel. replaced all good, power back, hopefully fuel mileage too!

i was right then?...... im always right. lol.

almost, still pinging, sounds like just the drivers bank....I may replace lifters on the one side, maybe collapsed

Collapsed lifters are noisy at idle, is yours? No sense replacing everything. How are your grounding points? Theres one on each side, next to the camgears attached to the frame rails that get corroded easily. Easy/cheap to clean with wire brush or flat screwdriver. Then I would do a pressure check on your radiator/cooling system, autozone here has a gauge for rental, it goes in place of your radiator cap and you pressurize it and see if it holds. most mechanics have one. I sound like a broken record but its a quick/easy way to check if heads are cracked. After that was confirmed good, I'd run a compression test. If timing is right, compression is good in all cylinders then id check into the electronics.