Hi Guys, first post...nice forum. Lotta knowledge here, for sure. I just spent a bit of time searching and have a fair idea of things to try, but wanted to run this by ya'll anyhoo.

1991 3VZE, 5 speed, 200 k-something (speedo cable broke two years ago - really gotta fix that).
I get pinging at steady state cruising, light to no load, any rpm, any gear, any speed. If I very gently accelerate, or very gently let off the accelerator, it stops. Octane and brand of fuel makes no difference.

Waddya think?

Thanks very much in advance...

~Chuck

 

I'd start with the spark plugs, check the gap and overall condition.

Then SP wires. Test them for resistence.

Then then ignitor coil. Also resistence tests, primary and secondary.

If all that's good, then check your timing. It would be odd to be pinging all the time unless it was way off. If you suspect so, then check it first.

If all checks are good with the ignition, you may have carbon build-up in one or more of your cylinders. This creates hotspots that cause pinging if it's bad enough.

That's my best guess with what your givin' me so far. Good luck.

 

hey man, im not sure if you have the same problem i had or not, but i have the same engine and all and i had that sound comnin from mine and it turned out to be a wristpin. i dont know if thats your problem or not, but it sounds like what mine was doin. it would do it when i stayed steady on the gas at any speed. i could let off a little bit or give er some more and it would quit until i steadyed out again. like i said, i dunno id thats your problem or not, but i would check into it. later man.

 

Knock sensor

 

check the throttle position sensor. mine was bad not letting the base timing set right. when i got the new one and checked the timing it was at 30`, when it should be at 10`.

 

I just had to smack myself on the forehead when I read that. Duh!, the knock sensor. Yeah, that might cause knocking if it's bad, ya think? I feel retarded for not saying that first...pun intended.

 

May not be the problem. Check everything else before you drop a couple hundred bucks on replacing the knock sensor (sensor, sensor wire, gaskets, etc.). If you take this route - replace the knock sensor wire too! While your in there, might as well replace all the injector rings and seats - you'll bump at least one of them hard enough to cause a leak.

 

I've never seen a ping at partial throttle be the knock sensor...

I had a rather lengthy thread about the same exact ping that had a bunch of good suggestions in it. What ended up solving mine, believe it or not, was a 180 tstat, new pressure cap, new water pump and a new radiator that I changed because I had an intermittent running warm situation. The ping disappeared as soon as I changed all of that. I'll dig you up a link to my thread...

 

https://www.yotatech.com/forums/f116...highlight=ping

That's a good read...

 

Wow! LOTS of good information and ideas. Thanks Guys!! I really appreciate it!

I'll start with the simple stuff - plugs, wires, timing, etc and go from there.

The thing runs great - just would like to lose the pinging.

Again - Thank You!

~Chuck

 

hey man,

I've got a very similar issue, same pinging, mine is not all the time but definitely under light load. Timing and everything is ok, now I suspect it could be issues with restriction in exhaust as I have very little power over 3000rpm but boy does it rumble. Gonna pull cat out and drive w/o it to see if this theory holds up.

 

In all honesty, lot's of engines ping. How strong of a ping and if it might be detonating is the? Get some gearhead passenger's to give you an few opinion's. This is a got to hear it kind of thing.

 

Overdrive, this may be my issue

I have had a ping for a long time, but i have new plugs, wires, rotor, coil. I have to keep my timing at 0 btdc and if I use premum gas i get very little pinging. If i up the timing to 5 btdc the pinging is so bad it starts to sound more like pre-detonation and i get the worst sulfer smell.

I know that my cooling system is off, (because it reads fully heated within about 60 seconds of startup, but since i have never "overheated" i never figured it would be causeing other problems.

Also how can a bad knock sensor "cause" pinging? I understood that it retards timing when it hears a knock, but if it was not functional I would think that it just wouldn't be fixing your pinging rather than actully causeing the ping.

 

Good, I hope my post helps you then.

Be prepared to demand the cooler tstat in the autoparts store. The clerk I went to all but told me I couldn't have it until I just told him I was willing to take the risk.

My truck hasn't pinged since, but I do still run premium.


As for the knock sensor, I agree with you. When someone posts a pinging thread people always say change the knock sensor but from what I've seen that is almost never the problem.

 

Chuckracer, for what it is worth my 1993 3VZE had the exact same symptom. It would ping at very light throttle, and either accelerating or decelerating would make the pinging go away.

I had to rework the heads, and in the process discovered the knock sensor wire was eaten through (thank you mice). I put in a new wire and it never pings now, with timing set per the FSM.

I can't say for sure that it was the knock sensor wire, as I also cleaned off the carbon on the piston tops. It was not the TPS, as that was within spec when I tested it on the bench.

 

1990 3.0 with the same problem. Question for others here about this. This ping has become louder over time. I beleive that it is a wristpin, but would a knock sensor cause the sound to change over time.

Just replaced T-stat, water-pump, timming belt, plugs, wires, cap, rotor.

Is this knock sensor easy to get to? Or does it require you take the top over the engine off.

I have looked into getting a reman'd engine put in, but I really don't want to dump 3700 into it if I don't have to. I have other plans for that money like an SAS.. but the engine comes 1st..

I am currently deployed so I have been writing stuff down that I want to do to my truck when I get back. Any other info would be greatly appriciated. Just trying to cover all of my bases before I have the engine replaced.

Thanks
Jeremy

 

lots of good ideas here so check up on what's already written
abnormal cylinder temps (from carbon build up, valve adjustments, egr function, timing, fuel delivery issues) is a cause of detonation.
contamination of the air/fuel mix caused by too much blow-by being drawn in through the PCV system or by oil otherwise getting into the combustion chamber is another since oil lowers the octane rating of the fuel.