1994 Camry Hesitation problems

[mickie1]

New member here. I purchased my 1994 2.2L auto with 135k about 2 months ago and it has always had a hesitation problem from idle until around 3000k rpm. Also the idle is not consistent and blips from about 800-400 constantly if in drive, but not when in park or neutral. I searched for "hesitation" and found a few threads that were helpful, but seeing as some people ask questions, but never update to what the actual problem was it is hard to determine.

From what I gather I need to check the EGR and for a possibly vacuum leak. It has a full tune up done including timing belt. The distributor was also replaced with a new unit. I ran the self diagnostic but the light just constantly blinked, so I would gather that as being a code 1 (no errors). There is not a check engine light on normally. I am also pretty sure the O2 sensor is original. I am getting spark to all cylinders as well. I am going to replace the fuel filter this week as well for peace of mind. If anyone can give me some better words to search for or any idea of what to check to fix this, it would be appreciated. I tried to be as descriptive as possible, but of course I am sure some things are left out. Thanks in advance.

[davemac2]

When the idle is not consistent, it's usually indicative of a dirty/bad IAC valve, vacuum leak, bad sensor such as MAP, intake air temp or ECT sensor. The I4's have a fairly small IAC valve which is more susceptible to clogging. The steps you should take would be to remove the IAC and clean out the ports, measure the resistance between its connection terminals (20 ohm +-2), clean out the intake and throttle body by using a seafoam cleaner or Amsoil Engine foam cleaner (the one I prefer). Replace the throttle body gasket while you are at it.

Inspect your vacuum hoses well. The PCV valve hose can disintegrate at this age with oil blow by. Inspect the MAP sensor vacuum hose well also since a leak there can produce a false MAP reading. Hesitation with idling issues up to 3K would sound like a major vacuum leak to me. (if we assume only one problem here.) Be sure to check the brake booster vacuum hose well. You may want to verify that the brake booster can hold vacuum with a vacuum pump. Check for intake leaks around the intake manifold using carb cleaner, brake cleaner, propane, etc.

Next, I would check the ECT sensor, then the MAP sensor. Inspect the connectors for these carefully to make sure they are not corroded.

If we assume there may be more than one issue, then the hesitation can also be caused by a bad spark plug wire or bad plug. If you don't know the age of the plugs or wires, replace them anyways for reliability.

Other remote possibilities would be a leaking head gasket, a clogged cat converter. If the cat is clogged, you should notice poor power performance, slow pickup. The leaking head gasket would probably affect warm idle more then cold, but maybe not. If nothing else pans out, maybe by a block tester or get a test done to check the head gasket.

I'm not convinced of a bad EGR valve if it is a consistent bad idle and hesitation, and you don't get actual stalling when coming to a stop.

How is the gas mileage? Are there differences between a cold engine vs. warm with the symptoms?

It may also be a bad injector. That may be hard to diagnose though unless you take them out and have the ability to test them.

good luck

dave mc

[mickie1]

Thanks for taking the time to post all that information! It is way more than I was expecting and hopefully sets me in the right direction to fix it. I have uploaded a video of the tach at idle in drive, and then driving off. It is taken with my Moto Q cell phone so quality is not the best, but I believe you can see how the idle is jumpy. When I am taking off I pretty much have the gas floored and have to drive like this in order to not get hit by other motorists. I will research some more on the items you listed and try to find time this weekend to fix or clean a lot of them. Thanks again!

Ok some reason the video is not working, but I will try to find a site that will work.

[mickie1]

Here is a video

http://www.youtube.com/v/RwiEnSSPEHU

[dleccord]

Originally Posted by mickie1

Here is a video

http://www.youtube.com/v/RwiEnSSPEHU

bump because my camry idles like that and I already cleaned the IAC valve.

[Eye8Pussies]

you can pretty much rule out the iac (mostly, but not totally) and vacuum related issue if it doesn't idle like that in park.

since it only does that in drive, it is an issue related to when there is a load on the engine.


I would actually check your timing belt to see if it's off by a tooth, as well as check the distributor, since you said that they were recently done. this would also explain the extreme lack of power.

the question is: was the same problem present before the maintenance work? or did you buy the car with the work already done? regardless, look into it.