Question, if the knock sensors are bad, would that throw a code, or not?
How To Stop Pre-Detination Rattle?
- Thread starter LFD2037
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Yes it would. When I did my head gasket, I accidentally killed a knock sensor. I pulled codes after putting everything back together, and it was blinking for the knock sensor.
could something have been botched in a HG job that would prevent the timing from being properly adjusted based on the sensors values? I just can't picture a healthy engine with such a low compression ratio and full sensor protection knocking on clean gas no matter how high the intake temps get. Baffling me.
Update on mine: I took it to the shop where I had me HG done and had them do a ride along and listen for it in the shop. They confirm its coming from under the valve cover and suspect that's its the valves, specifically the exhaust valves at the front of the head. They think the tolerances on the exhaust side are out, Ill find out more next Friday.
It's a money pit! It's a terrible engine! Toyota sucks! Sell it fast!!
NLXTACY
Wits' End
Sooo BENO is like that really cool uncle that hasn't diddled you growing up but does tons of shrooms and drinks a ton and sometimes his posts go less than appreciated when in reality he's being sarcastic as hell but the synapses are mis-firing and when the hair of the dog kicks in he will realize that not everyone gets his sarcasm and apologetic PMs will rain down along with everyone else on here who personally know Beno vouching for his drunken stupors
I think the sarcastic point was possibly directed at the fact that this thread should have stopped after 6 posts 5 days ago until you had a chance to perform some of the checks recommended. Put your timing back, check AFR's and test O2 sensors and report back.
LFD2037
TEXAS LEXUS!
- Thread starter
- #51
Still does it w/timing @ 3*, AFR's are good, O2 sensors are good but I ordered new one anyways (be here next week). Now what?I think the sarcastic point was possibly directed at the fact that this thread should have stopped after 6 posts 5 days ago until you had a chance to perform some of the checks recommended. Put your timing back, check AFR's and test O2 sensors and report back.
I got that it was sarcasm but it wasn't funny nor helpful. Just useless.
94SRUNNER
GOLD Star
Have you inspected the cylinders for carbon build up?
Hey LFD2037. Have some input that I've been pondering. I'm new to the cruiser so haven't dug in a lot to the engine and TS because so far my new rig has been running fine. I believe detonation is fuel burning poorly and pre ignition would be like carbon causing fuel to ignite. Detonation #1 reason is bad fuel or high temps causing fuel to burn improperly and lean mixture. You haven't mentioned poor idle or detonation during idle and you say no codes other than pending. Yes it could be bed injectors spray etc but I don't think that is it. I would suggest you check your egr valve and make sure it is not clogged or frozen shut. On the TS tree this is like number 4 on the list. I Believe (haven't dove into the diagram) the ECM doesn't see the position of your egr valve but it monitors the vsv and as long as that is working the ECM believes the egr is working. If your egr is not opening or clogged your cylinder temps will be higher in the rpm ranges that you mentioned - when the egr should be open. This may also cause your pending codes- improper burning of fuel the o2 sensors see. The egr is closed during idle so that is why I mentioned it earlier. Good luck
LFD2037
TEXAS LEXUS!
- Thread starter
- #54
Egr system checks out good with new modulator. Noticed it pinging this morning so thats new that'll it do it when cool outside (intake temp was 82*). Also, it'll ping/rattle as long as I hold the throttle in a set position (keeping load on the engine the same). The only thing that stops it is me applying a different amount of throttle (changing the load on the motor). Should the knock sensor prevent it from that? And when I left off the throttle, like exiting a highway, UltraGauge shows front O2 sensor at 0.00 volts. Shouldn't it always be between .1 and .9?
Cool. So the engine misfires and almost dies at idle when you apply vacuum to the egr. I am not sure about what your o2 sensors should be reading.
LFD2037
TEXAS LEXUS!
- Thread starter
- #56
I randomly pulled the 3rd plug from the front to check piston top for carbon. Piston top didn't look as bad as I thought it would after having an oil sucking PCV valve but the plug looks like its running lean. Plugs only have about 7,500 miles on them. What's it look like to you?
That's why I said check you AFR's with a wideband. My money is still on fuel problems.
Well it depends on why they are off. If it is lack of fuel it could be replacing fuel pump, replacing the pre filter in the tank, replacing the fuel filter, checking your pressure regulator, etc. If it isn't lack of fuel but lack of proper fuel metering, it could be your MAF, O2 sensors, etc. But the first thing to check is if they are off, and I would be willing to bet that they are and you are running lean.
Now those are some textbook lean fired plugs. I don't know how you'd check the AFR. But have you checked your fuel psi? Couldn't you disconnect and plug the vacuum line to the FPR and vsv and run it. This would give you max FP. That is if you don't have the equipment to check the FP.
