I was trying to think how a vehicle firing on 2 out of 6 cylinders could idle really nice and got a headache.
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If it idling gives you a headache, think of the fact that the other summer I was able to take this car down the road like that. I didnât know then that it was running on 2 cylinders. It had a serious power problem and had to ride the clutch to get it going. Should be a guy picking it up tomorrow to look at it who is better at these things than I. This car has been to a Toyota Dealership service center and a college auto service and neither of those could figure it out. The second I can understand but Toyota themselves?
The compression seriously sucks and youâre wondering why it hasnât run good since you got it?
The only engines that run well on compression that low are air cooled VWs and thatâs simply because of the very low compression and cam profile.
The odds of this being related to any valve lash issues are about zero as that hardly ever affects more than one or two cylinders at a time.
That doesnât say much for the Toyota dealer or the college auto service center. The college must be sending their grads to work at the Toyota dealer⊠
I have an beater 91 Buick that I tested compression in over a year ago had around these same numbers. As I said it is a beater, but it runs fairly well. It starts fairly easy in all temps and has reasonable power.
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Itâs difficult for a diyâer to get accurate compression numbers, either due to an inexpensive and inaccurate gauge, or the test method. So itâs possible compression isnât the issue in this case. But if those numbers are accurate they are pretty low. Iâd expect it to show up in hard starts and poor acceleration if thatâs the case. Idling might be ok once you get it started. Is this car stubborn to start?
No it starts right up and keeps running nicely. It started up hard last week when I started it but that was because it has been months since last started. Every time since it starts within a second or two.
If idling, does the engine respond the same to pulling either cyl 1 or 6 spark plug wire?
When you pull either 1 or 6 it pretty much shuts off within a few seconds. when you pull off all four of the others it has no change. I took it for a drive today. Got it up to about 10 mph until it would cut out, let the gas off and it would idle and go again.
I had someone pick it up today who are going to work on it. Winter starts next week here in Wisconsin pretty much, so Iâm letting someone else screw with it. I will let you guys know if they find anything.
I think your individual injector filters are plugging up. Try spraying ether into the intake to see if the idle jumps. Try switching 1 or 6 injector with another to see if the problem moves.
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I am still not convinced you have the firing order right. Try swapping the 4 dead cylinders wire to the other side of the cap. It costs nothing and only takes a minute. What have you got to lose?
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I again let myself jump into considereing the engine a V-6. Just ignore me, please.
In my opinion thereâs no way this car would drive on 2 cylinders. Something else going on here.
It runs 100% the same with or without spark plug wires 2, 3, 4, and 5. It drives but obviously not very good. Not enough power to move the car, even being a lighter car beyond 10 mph.
I did try swapping the 4 dead cylinders on opposite sides. It seemed to run slightly worse if any change at all.
Might pay you OP to ask a shop with an oâscope ignition analyzer to take a look whatâs going on w/the spark to all 6 cylinders. That machine allows them to enable or disable each cylinder one at a time just by pressing a button. And they can observe the ignition waveform to all 6 spark plugs. Just hooking it up and doing a diagnosis shouldnât cost that much. They can tell you what they found and you can go from there. No need to re-invent the wheel.
The place I took it to believes it could be the knock sensor is causing the computer and control modular not to work right with each other. Causing the 4 cylinders not to fire.
I have had mixed thoughts on this sensor. Some experts say it does not matter, some, one that worked at a Toyota shop said it could. Some amateur said the same. So the next attempt is to find out for sure. I am going to have him drill and hold and tap it in the exact spot that this knock sensor was suppose to be. This way we can put to rest once and for all if that is or is not the problem. I have the original shot block that will show these guys exactly where this little bastard needs to be.
I still think youâre headed down the wrong road with some bad advice from the shop but best of luck.
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Could be, but Iâve always wondered about that stupid knock sensor. This way I should know and these guys donât charge much.
Usually what would happen if you had a knock sensor problem, besides maybe a diagnostic code, is that youâd hear the engine pinging sometimes, like on hard accelerations or going up steep hills. Pinging can range from barely noticeable to so obvious it canât be ignored, depending on the engine operating condition. Still, it is usually a good idea tho to resolve all the known issues first, when debugging some difficult to diagnose problem. Best of luck.
This guy after months said he will not work on the car. I am thinking it is likely a fuel problem with the injectors. It has good fuel pressure going into the injectors, but the 4 injectors may not be working properly. This guy said he tested the injectors, but I think he did nothing. It did run much better the summer before last summer as far as top end speed goes. Last summer it would only go a max of 10 mph the summer before it got close to 50 making me think the injectors have gotten worse over time. This so called mechanic said it was because of the engine being a couple years older. I donât buy that. All 6 cylinders have great spark, decent compression but the 4 middle cylinders are not working.
We have already determined you do NOT have good compression
FAR from it in fact . . . I just scrolled up, and you yourself said your compression ranges from 110 - 130psAt
Have you performed a cylinder leakdown test?
I wouldnât be surprised if you have some very serious leakage
please do that test and report the findings
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