My 4-runner feels like it has lost about 200 rpm and is only getting 18 mpg. I have had the plugs changed, an injector flush performed, changed the air filter. This all seems to have started after the transmission was overhauled, due to it not shifting correctly. It shifts fine now....but it justs seems like it is running at 200 rpms harder than it used to run.(Runs @3000 rpm to get 70 MPH when it used to run 2800 rpm)
We had the catalytic convertor checked and there was no plugging detected.
SOURCE: Toyota Camry Automatic Transmission Jerking Shift
Not likely to be the clutch pack as you dont mention slipping wich is the normal sign of overheated or worn clutch bands.Not sure with your vehicle but 2 methods that control the shift severity are engine vacuum or pump pressure inside the auto. so check balls are a possibility. They are spring loaded to open at a set pressure,or close.Could you check to see if its a vacuum controled and if so its a lot easier to fix as the vacuum control should be outside the trans.
SOURCE: 1996 Toyota Camry is slow to change gears when accelerating
Automatic Transmission: Is your speedodometer working fine? Not jumping around one irratically? My inlaws Ford Taurus would act like that, but when their problems were present their speedo wasn't functioning. I changed out their speeo sensor and the problem was solved. I'm not saying that's your problem, but if your computer is relying on your speed sensor to tell it when to shift and the sensor is not working it the computer will go into a safe mode and not allow the transmission to shift (automatic transmission) out of 2nd gear. Otherwise I would lean toward transmission troubles. Could be as simple as changing your transmission fluid and filter. If the filter has never been changed with those kind of miles its long long overdue. All you do is jack up and support the front of your vehicle on jack stands remembering to block the rear wheel with a 2x4 or something large that the vehicle can't roll over and then place a drain pan under the transmission oil pan. If it has a drain plug then simly remove it and drain the transmission fluid into the drain pan. When done draining, replace the plug. If it doesn't have a plug then you will have to loosen all of the bolts holding the Transmission oilpan just a little bit and then work on loosening the bolts to the rear of the oil pan so that it drains from the rear of the pan allowing you to more accurately determine where the fluid is going to come out at. You may have to lightly pry the pan loose from the transmission if it doesn't start to drain once the rear bolts are loosened. You want to only loosen the front bolts about 2 full turns and then gradually as you work your way back loosening them just a little bit more the closer you get back to the rear of the transmision oilpan. The front of the vehicle is already up in the air so the oil should run to the back of transmission oil pan. Finish draining it and then remove all of the bolts and remove the oil pan from the transmission. Look at the new filter so you know what it looks like when you look for the old one to remove. Look to see how it is fastened up into place and remove the bolts / screws holding it in place and then remove the filter and put the new one on. You may have the design where it's held on by pressing it on with your hand because it has a rubber seal attached to the filter. After the filter is in place you need to use a clean rag and clean and dry the mating surface on the transmission where the oil pan touches. If there is a gasket there then you will have to remove and replace it with one from the Filter Kit. This should be done anytime you remove the pan. If it is a rubber style gasket then you will not need any RTV sealant. If it is a paper or cork gasket then you need to purchase a sqeeze tube of RTV sealant. Pay attention to the package details of the RTV because not all are for transmission fluids. If you need to use the sealant then read the directions carefully and then re-install the new seal. Put the Trans Oilpan back into place and if you are using RTV then make sure that when you are tightening down the bolts that hold the pan to the transmission that you do not over tighten. You don't want to sqeeze all of the sealant out from between the mating surfaces. Remove your jackstands and unchalk your rear wheel, then lower your vehicle back down. Under the hood you will need to find where the dipstick is and with a funel, refill the transmission with the recommended transmission fluids that is right for your make and model vehicle. If you are not sure then ask your local parts store.
Manual (Stick Shift) transmission: you may have a bad clutch or worn out throw-out bearing. If you let out on the clutch and the vehicle feels like the clutch is still partially engaged and it takes a lot more gas to get to speed, then it sounds like you've smoked your clutch due to either normal ware and tare or operater driving habbits. I would look into replacing the clutch. Inspect the flywheel for discoloration like bluing or yellowish colored metal that idicates that it has gotten HOT. You'll have to drop your transmission out and then you will need to remove the clutch and fly wheel. Inspect the flywheel for cracks. If you see hairline cracks around the bolt holes or anywher else on the surface then you'll have to replace it. If you do not see any cracks then take it to shop or parts store that have the capabilities and can look it over to make sure it didn't get to hot (to hot means the temper in the metal has been taken out. Temper is the hardness of the metal, so if the temper has been lost, then the flywheel could be brittle and dangerous if re-used. You may be in luck and the flywheel didn't get to hot therefore allowing you to be able to keep it and just have them turn a new surface on it with their lathe. Just like when you have your brake rotors and brake drums turned. Replace the throw-out bearing, pilot bearing, clutch and presure plate. Re-assemble. You should buy one of those cheap (i.e. cost not quality) clutch alignment tools for re-aligning the clutch to make your job much easier.
If you are not comfortable with working on your own vehicle or don't have the tools then take it to someone who can. Recommend taking it to the professionals. These suggestions may or may not fit your specific problem(s), but without knowing more information these are merely suggestions.
SOURCE: 1991 toyota 4runner v6 auto rough start
Possibly a leaking head gasket. Water/antifreeze seeps into the cyllinder when it cools off, and then it won't fire properly until the coolant is blown out the exhaust when you start it. Let it warm up with the rad cap off. If you see bubbles continuously coming up to the filler hole, you have a head gasket problem. Do you have to add coolant monthly, or weekly?
If you're lucky, it could be just a spark plug that doesn't want to do anything until it warms up, or it could be a valve.
SOURCE: 2000 Toyota 4 Runner, 3.4L, 6 Cylinder. Engine
look at the plug wires they are known to bust when old near the boot
SOURCE: 1991 Toyota land cruiser.. vibration, sputtering??
One of the plug wires may be arching or have a defective spark. It's odd, but I check mine by removing each plug wire one at a time. I'll use stick the end of a screw driver (insulated handle) in the plug wire and check the spark coming in from the coil/coil pack/distributor. Keep in mind, the engine is running and I only do this if there's no shop open or close by. Also the insulated handles are for that unwanted shock. Has he checked for sparks at night with the engine running. Look around and follow the plug wires and around coil/coil pack for any jumping sparks. If any are seen, there's your problem.
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Yes....there was an issue with the temperature on the coolant....which was the cause of the transmission not shifting properly. We had the radiator and entire cooling system flushed...and then I also had a new radiator installed. The temp gauge runs right in the middle.
My 1999 4 Runner just dropped from over 20 mpg down to around 16 mpg. I had the mass air flow sensor replaced a few months back. Any ideas?
What was happening is the coolant was not at the correct temperature. The Overdrive does not engage until the coolant temperature reaches 177 degrees F. This would cause the high RPM that you are speaking of. Your transmission was not making the final shift. Doing what you posted was the correct thing to do. I hope that my advice was helpful.
This may sound stupid, but, I need to know where your temperature gauge is reading. You may have a problem with the coolant temperature, which will def cause your issue. Please advise.
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