smooth start, but rough acceleration

[burndog]

any ideas? 89 camry...starts like a dream and idles nicely but hesitates and accelerates roughly. 120K miles. Pulled and regapped plugs and cleaned contacts inside dist. cap, and replaced air cleaner.

Check engine light does light on startup, but is not on when running. This is my wifes car. When it first started doing it a while back I asked her to add fuel injector cleaner. She did this on a couple of new tanks of gas, and may have helped just slightly (placebo effect maybe?)

She claims that it seems to get worse when tank is at about 1/2 full, and usually (though not always) seems to be better after filling the tank.

A bit of history...not sure if this has anything to do with it, but about 6 months ago we were driving when smoke started coming from under the hood. We immediately pulled over and I found that the smoke was from oil that was on the exhaust manifold. I went to pull the dipstick out and it basically shot out of it's tube. I figured that it may have been over filled, but checked when we got back home and it was not. It seemed to run alright after that, and I was pretty nervous about the whole thing, but told her to keep driving it, but to be on the lookout for anything suspicious. I have no idea if this has anything to do with our current problem of rough accelaeration, but figured I should mention it. When I pulled the plugs this weekend the gap was large on all of them. The plugs themselves seemed to be alright, however one had oil covering the insulator and end of it where the boot slips onto it.

Any ideas, from reading it seems like most with poor acceleration also have poor idling, and get the advice to clean the EGR valve. It does however sound like it can be a problem to get off, and I would hate to go through the trouble if it is not the problem

Where should I start. Any help would be greatly appreciated. I do want to sell the car as we have bought another one, but will surely get a poor price as it is running right now. Besides this recent problem the car is in excellent shape with low mileage (at least for the year) and I would like to recoup some of the money we invested in it.

[Mike Gerber]

First it is always best to give the current mileage when asking for help with a problem and which engine the car has.

Most problems when accelerating are caused by faulty ignition system components. How old are the cap and especially the spark plug wires? Have you ohmed out the plug wires? Have you checked the coil inside the distributor with an ohm meter and also inspected it for hairline cracks? Coils on the first 3 generations of Camrys can cause porblems when they accumulate lots of miles on them. Another thing that can cause problems on acceleration on a high mileage car is the fuel pump. Have you checked fuel pressure?

The dipstick shooting out of the tube is strange. The only thing that I can think of that may cause that is a defective PCV valve. Check the valve and make sure the check ball inside of it is free or just replace it. It's a cheap part. Maybe others can give you some additional thoughts on that. As far as the oil on the one plug that is usually caused by loose spark plug tube nuts on the top of the cam/valve cover. Remove the plug wires and tighten all the 30MM nuts on top of the cam/valve cover to 17 ft. lbs. in 3 even passes (6, then 12 and then 17 ft. lbs.). Did you ever determine the source of the oil leak on the exhaust manifold; it may be time for a new cam cover gasket.

Mike

[white90dx]

If the motor is a 4-cylinder, there is no PCV valve. The crankcase vent goes directly from the valve cover to the intake manifold. It is possible that it is plugged up, so check that (this would cause an overpressurized crankcase and possibly oil shooting out places it shouldn't).

As for the running/accelleration problems... you will want to change the wires+cap and rotor along with the ignition coil. Based on your statements, the plugs are probably fine. Get OEM Toyota wire+cap and rotor - they really are better. An aftermarket (Autozone, whatever) coil should be fine.

-Charlie

[Doctor J]

driveability issues related to the fuel level can point to the evaporative emission system [charcoal canister] or very rre the deteriorated fuel pump discharge hose [about 2 inch long connects the pump to the high pressure tube inside the tank]

[burndog]

Sorry, the engine is indeed a 4-cylyinder ( 2000 cc 16 valve ). Bear in mind that I am a rookie. Now I checked the ignition wires. With my meter set at the 200K setting...readings were (from shortest to longest) 3.5, 6.2, 13.5* and 18. Now the one that I have listed at 13.5 was jumping all over the place up to 58. It is rusty inside the fitting that slips on the dist. cap. adn 'rusty like dust came out when I tapped it. After cleaning the best I could the reading was a steady 13.5. I took the car for a spin and I did not notice any difference.

Are these readings about normal??? I read in one place that irregardless of the length that anything under 6 is bad. Now to confuse me even more, that article said to set the meter to 20K. My meter only has positions for 200, 2K, 200K and 20M. Please forgive my ignorance when using a meter.

I really do appreciate the help and thank you for your input, and look forward to your reply

[burndog]

well I replaced the plug wires ( cap came with them) and the rotor, and all is fine now...running like a top. A sincere thanks to all those that responded and for pointing me in the right direction.

[crug75hid]

This thread will help me a lot. I will check my 84 Camry and deal for its rough acceleration.

[burndog]

The thing that threw me off was the car, although running a bit rough, was not all that bad. In trying to clean up the plug wires again I found that there was absolutely no continuity in one of them ( I must of messed it up while trying to clean it). Surpisingly the car was sluggish, but not much worse than before.

I took a reading on the new plug wires at 200K setting and they ranged from between .2 and .4 Now that is quite a difference from what the old ones were (I still haven't figured out how to interpret the readings on the multi-meter.)

When I went to check the coil the manual said to test resistance between the + and - terminals and I got 1.2, and the reading was supposed to be .38 to .55 or something like that, and I thought oh no, it is the coil ( which means pulling the distributor. I am thinking that my cheap meter when set at 200 just does not cut it at the really small numbers, and decided to replace the wires and cap, and sure enough it is running like new again.

ALthough I am in no position to give advice, I think the guys who know what they are talking about (above) check the ignition system first if it has sluggish or rough acceleration.

Thanks again to everyone.

[Mike Gerber]

"The thing that threw me off was the car, although running a bit rough, was not all that bad. In trying to clean up the plug wires again I found that there was absolutely no continuity in one of them ( I must of messed it up while trying to clean it). Surpisingly the car was sluggish, but not much worse than before."

The wiring inside the insulation was probably broken. Under light load the current can jump a small gap, similar to how the spark jumps the gap of the spark plug. When more current is needed, like under acceleration, it just can't jump that gap inside the wire.

Mike

[ford_jj]

Originally Posted by crug75hid

This thread will help me a lot. I will check my 84 Camry and deal for its rough acceleration.

I 'll check my 89 Camry too. Thanks a lot.