Q: I notice that in the cooler months of year my gas mileage declines and at times my engine seems to run rougher, any ideas?

A: This is normal depending on how much the temperature changes where you live. The engine needs more fuel to run in cooler climates because when the fuel enters the intake manifold it condenses so more is needed to get to the cylinders. The other reason is that the major gasoline companies will change the gas formula for the climate changes, they do a good job but all vehicles are not created equal. My advice is to realize that some minor performance problems can be expected and any attempt to adjust for the variables will frustrate you and your servicing dealer.

Q: I have a 90 Tercel that stalls when its cold and does not have all the power it once had, any ideas?

A: You have a carburetor problem and a emission control problem. This can be involved or routine ,since no two vehicles are the same. DO NOT take this problem to a non-Toyota garage, if you do most likely you will get a new carburetor and the condition will still exist. Toyota should have corrected this years ago, but failed to admit the problems. This is a very dirty (emissions wise) engine. If the vehicle only has had normal maintenance then the engine valves are carboned up and leaking and the piston rings are stuck. I'm advising you to see a dealer and have the engine evaluated for repair or trade out of this to another vehicle.

Q: I own a 86 Corolla with a automatic transmission. Recently, I had the catalytic converter replaced. Since then, the car runs great for about the first 2 minutes. Then it hesitates severely (stalls sometimes) for about 2 minutes. Then it runs great again. The trouble happens when the temperature needle is roughly halfway between cold and fully warm. Any ideas?

A: Several things come to mind. It's unusual to need a catalytic convertor at all, normally the problem is something else that caused the problem. If your carb is allowing too much fuel into the engine it will harm the converter or if the ignition system is not firing on all four cylinders unburned gas will also harm the convertor. . You may have a restricted fuel filter, ignition coil that is starting to fail or choke problem that is not letting it open fully when needed, but warms up when you are sitting beside the road allowing you to drive normally until it cools.

Q: I drive a 89 Camry and every time it gets really damp or misty outside the engine won't turn over, it tries but won't start. Then when it's dry outside after a few tries it starts up again??? Adam S.

A: Your Play misty for me is a familiar problem. You have probably one or two causes. The first is that the ignition wires have dried out which allows moisture in changing the current flow to the plugs. The second is missed by a lot of people, the ignition coil in the 87-91 Camrys also have a moisture sealing problem which shows up in damp weather. I would replace the distributor cap and wires first,if you already haven't, then if it continues replace the ignition coil. Don't go to your nearest parts store for parts spend a little more and go to a Toyota dealer, the factory parts are far superior.

Q: I have an 87 Celica and the engine hesitates often, I've had my mechanic look at it but after many dollars spent it still does it, in fact its getting worse. Help me soon. Mark F.

A: Don't despair I think that I have a solution. If all the items that you mentioned were done correctly and if the timing belt is installed correctly then have some one check the large tube that connects the air mass meter and throttle body. These are known to dry out and crack which lets extra air into the intake. If you find cracks then replace the bellows and your Celica will return to normal. Vans also have the same problem.

Q: My 92 MR2 has a spark plug wire that keeps working its way off. I have replaced the wires but it still comes off. Any ideas? rconder.

A: If I has to guess it is that you are not using Toyota wires as replacement. Normally I see this when non-Toyota parts are used. You may also have an oil leak in this area and oil will cause a spark plug wire boot to swell and cause the same problem.

Q: My 1988 Camry continues to stall during any kind of wet weather . I have replaced the spark-plug wires , the rotor cap and two seals on the coil . the engine runs fine until I drop it into gear . any ideas ?? mc

A: Now you can replace the coil and it should fix the problem.

Q:1994 TOYOTA TERCEL 1500 12 VALVE AUTO TRANS (55500 MILES)
I HAVE A PROBLEM WHEN YOU ACCELERATE OR LOAD THE ENGINE LIKE GETTING ON THE INTERSTATE HIGHWAY THE CAR SKIPS OR SURGES UNTIL THE RPM RISES THEN THE IT RUNS FINE. THERE ARE NO FAULTS SET IN ECU.
I HAVE REPLACED THE DIST CAP,ROTOR,IGN. COIL,PLUG WIRES,AND SPARK PLUGS(ND TYPE) AND FUEL FILTER WITH NEW PARTS FROM THE TOYOTA DEALER. I HAVE CHECKED THE MAP SENSOR AND FOUND IT TO BE WORKING PROPERLY. I HAVE CHECKED THE FUEL PRESSURE. IT CHECKED TO SPECS. LO READING AND HIGH READING.I HAVE USED THREE CANS OF FUEL INJECTOR CLEANER IN GAS. PLEASE HELP

A:I really have no idea. The Tercel with this engine has been flawless in how it works.
You should take it to the local dealer, they have a scan tool that will tell them what is going on when it acts up. The solution was that the timing belt was replaced elsewhere and was off 1 tooth.

Q: I bought a 1996 Camry 4cyl. new in august 1996 it now has 45,000 it has the calif. emissions I live in Mass. Starting problem it cranks but will not start , it always started with the first turn of the key now it just cranks until I pump the pedal real quick(not hard)to time it with the turn of the key and then it starts this happen usually after the car sits for 8 or 10 hrs. After driving then it seems to start a little better. I was told it was the AUL. valve or speed control valve . Someone else told me it was the IAC valve (Idle Air control valve). I couldn't find the AOL valve in the manual but did find IAC valve. Is there an AOL valve. Also are these parts on warranty. Toyota customer service seem to think it (IAC valve) is. But wouldn't be positive .Out of about 4 dealers 2 said yes and 2 said no. Your comments would be greatly appreciated Thank You.

A: In all likely hood its the Idle Control Valve. It may be out of warranty but if you have a good relationship with your dealer they may be able to get Toyota to help in the repair. The valve is fairly expensive.

Q: My car, 89 Celica, jerks from a stop when I am in first gear, (similar to how a standard jerks when someone is learning to drive a standard transmission). It does not jerk this severely, but it jerks enough. What could be the problem??
The car has been maintained very well so I have no idea what could be wrong. **I have no idea what size engine I have.

A: If the engine works fine in reverse then I would look or have someone look at the large black tube that connects the air flow meter to the throttle body.
My guess is that it is cracked and leaking air. This is fairly common with the Celica.

Q: My 91 Camry runs great every day except in the morning, and not every morning. When you start it up it runs fine, but after you drive it for five minutes, or so and stop at a stoplight, it will want to die and if you pump the gas pedal quickly you can raise the RPM's up to about 3,000. Once the RPM's reach that level you can take off, but if rpm's drop it will buck and kick, and cut out (Like it it running out of gas)if it does stall it is very hard to start, you have to pump the gas pedeal to get it to start. Once it takes this spell and you let it sit (at work) it is fine for the rest of the day, I mean it will NOT do this again! Also it will not do this every day. I believe whoever owned this car before us had problems and could not get it fixed!
THINGS I HAVE CHANGED:
Cold start injector timing switch (junkyard)
thermostat
plugs, wires, cap, rotary button
Help please, Wesley

A: You may have needed those items but my guess is that you did not need all of them.
Now go down to the local Toyota dealer and purchase a new ignition coil. Its located in the dist. This should solve the problem.