Engine hesitates - Toyota Nation Forum : Toyota Car and Truck Forums

hdsalinas · 12-01-2003, 03:46 PM

Hi,

I am new tow this forum since i just got a 1999 corolla a couple of weeks ago.

I have never been fan of toyotas but this little corolla has really grown on me. I have spent some time ad money getting it fixed up. I had to replace the brake pads and change the air filter. While at it i also replaced the PCV valve and fixed little things that its former user did not bother to.

I still have a couple of problems.

1) If you floor the gas pedal the car hesitates and strugles for a couple of seconds and then suddenly accelerates. The engine is very smooth and wont stall at idle and there are no engine lights on the dash and everything seems normal. It only happens when you press hard on the gas. I poured a bottle of fuel injector cleaner to the gas tank saturday, I hope to see some improvement.

What do you guys think it could be?

2) I have noticed that the radiator fan turns on as soon as you turn ignition key to on. On other cars (corollas even) the fan turns on and off if needed. On my car it stays on until you turn off the car.

Also, the fan to the right never turns on. I read somewhere that it only kicks in when the car needs it. Is that right?

There are a couple of annoying rattles. When you close the front passenger door it sounds like everything inside is loose. (need to fix that) .Also there is a small rattle coming from the top center of the dashboard (behind the clock) it sounds like plastic tapping on plastic. very annoying

I hope I find them!!!!

Over all I like my corolla. I just wish that its previous owner had taken better care of it. Is really in good shape but it seems that everyday I see a new scratch or blemish that I had not seen before (ej. the "T" in the toyota badge in the trunk is missing, so it now reads "oyota" )

Flashmn · 12-01-2003, 04:31 PM

Quote:

1) If you floor the gas pedal the car hesitates and strugles for a couple of seconds and then suddenly accelerates. The engine is very smooth and wont stall at idle and there are no engine lights on the dash and everything seems normal. It only happens when you press hard on the gas. I poured a bottle of fuel injector cleaner to the gas tank saturday, I hope to see some improvement.

Well, thats EFi for you, besides if you are at low revs, it will take some time for the engine to wind up to the powerband before it'll zoom off to the sunset.

Quote:

2) I have noticed that the radiator fan turns on as soon as you turn ignition key to on. On other cars (corollas even) the fan turns on and off if needed. On my car it stays on until you turn off the car.

Might be either of two things, broken relay, or a bad connection/broken connection at the thermostat housing where the relay switch for the fan is connected. If the wire is cut the fan will blow in all the time.

hdsalinas · 12-01-2003, 05:26 PM

Well, I dont think it has to do with the EFI system. When the engine does this, it shakes, sputters and then suddenly it accelerates. This is not only annoying but dangeroues if you want to cross a busy intersection and you need to get you corolla out of the way fast.

now about the fan, I think it may be the relay. But people here in Honduras (since is very hot) have the bad habit of removing the thermostat and connecting the fan directly. They really dont understand how the EFI systenm works and how doing this affects the engines performance. I am going to check and see if everything is there.

i just wanted to know if it was normal for the fan to stay on all the time.

One more question, when should the other fan kick in?

thanks for your replay flashmn

Flashmn · 12-01-2003, 07:45 PM

Quote:

Well, I dont think it has to do with the EFI system. When the engine does this, it shakes, sputters and then suddenly it accelerates. This is not only annoying but dangeroues if you want to cross a busy intersection and you need to get you corolla out of the way fast.

now about the fan, I think it may be the relay. But people here in Honduras (since is very hot) have the bad habit of removing the thermostat and connecting the fan directly. They really dont understand how the EFI systenm works and how doing this affects the engines performance. I am going to check and see if everything is there.

Yeah, funny how it may sound... those two things might be linked together...As if the fan is on all the time and theres no thermostat, well you'd be running with a cold engine all the time, and a cold engine causes lots of blow-by and it wears the engine out fast too. Have it checked, yeah they had that habit in the philippines too, its ignorance, thats why there is a thermostat, it'll open when needed and its designed to work that way. Ignorant mechanics think they're doing such a big favor in removing these factory made "safeties" (I guess you could call them those), when they are actually causing alot more harm in the process

Punisher · 12-01-2003, 10:12 PM

Ya know my AE92 4A-F does the same thing with the new carb setup now.. I don't know why.. I'm also having radiator fan problems.. I've checked all the wiring and it's all good and the relay is also fine but the fan won't come on when the engine hits the right temp.. It was working fine before I ever started this project.. I was told by someone that the stuttering may be caused by the thermostat being bad..

I knwo what you mean though.. like you stomp it and it stutters like it's going to stall and then VROOM it goes.. weirdest damn thing..

hdsalinas · 12-02-2003, 09:48 AM

Quote:

Yeah, funny how it may sound... those two things might be linked together...As if the fan is on all the time and theres no thermostat, well you'd be running with a cold engine all the time, and a cold engine causes lots of blow-by and it wears the engine out fast too.

I agree with everything you said but my engine is not running cold. The temp gauge always marks just below the middle. If you start the engine in the morning when its dead cold it will only take it about 2 minutes to get to that same spot and it never moves from there.

Quote:

I knwo what you mean though.. like you stomp it and it stutters like it's going to stall and then VROOM it goes.. weirdest damn thing..

I feel your frustration.

has anyone solved this?

Flashmn · 12-02-2003, 10:17 AM

Quote:

I agree with everything you said but my engine is not running cold. The temp gauge always marks just below the middle. If you start the engine in the morning when its dead cold it will only take it about 2 minutes to get to that same spot and it never moves from there.

Hmm, well... have it still checked, the corolla temp gauges are bit weird, for example you run out of water, the temp gauge wont move from that mark

. How I know? I had that happen...

Punisher · 12-02-2003, 01:21 PM

Yea, I've tried everything now.. so I'm guessing to just replace the thermostat.. probably with a junkyard one if possible.. if that fixes it I'll go get a new one.

Flashmn · 12-02-2003, 01:24 PM

Just get a new one imho, they arent that expensive to begin with.

Punisher · 12-02-2003, 01:34 PM

Ok, if they aren't that expensive.. just get a new one lol.. I hadn't looked at prices for one soo..

Just kinda weird how this all started after I did my mods.. after I had the coolant fluid empty from the system.. etc.. makes me think that maybe it is the thermostat...

hdsalinas · 12-02-2003, 04:28 PM

Punisher,

How hot/cold does you engine runs? Also does your radiator fan comes on and off or it just stays on like mine.

My family had a 1988 Dodge Caravan V6 some time ago and I remember that this ignorant mechanic once removed the thermostat and connected the radiator fan directly and disconected the coolant sensor to relieve an overheating problem that we had then. I dont remember if it fixed it or not (probably did not) but it messed up the engine.

the engine not only did the exact same thing that my corolla is now doing but it would stall while driving and at idle for no particular reason. That mechanic messed that V6 pretty bad.

I did not know anything about EFI until then. I started studying a haynes manual we had for that car and read all about those sensors and stuff and reconnected everything they way it was supposed to and replaced the thermostat. the result was a close to normal engine performance but it still overheated. It turned out that it was a clogged radiator.

The moral of the story is that both things are linked toguether as flashmn said.

I am going to check my car again this weekend. I ordered a haynes manual from amazaon and I should be getting it any time this week.

hdsalinas · 12-02-2003, 04:31 PM

Punisher,

BTW, when you change the thermostat, let me know if it helped.

micro214_kp61 · 12-02-2003, 05:55 PM

Quote:

Originally posted by hdsalinas
.1) If you floor the gas pedal the car hesitates and strugles for a couple of seconds and then suddenly accelerates. The engine is very smooth and wont stall at idle and there are no engine lights on the dash and everything seems normal. It only happens when you press hard on the gas. I poured a bottle of fuel injector cleaner to the gas tank saturday, I hope to see some improvement.

What do you guys think it could be?

i would check the fuel lines, the fuel pump and fuel filter. sometimes if there's a pinch on the fuel hoses/lines, the engine would hesitate coz there's not enough fuel coming in. just check it to be sure.

Flasmn... my dad had to replace the termostat on his toyota corona twice in 1 year. not only because the weather but mostly the traffic. it's literally stop and go traffic over there, so for them to bypass it would cheaper at that time but in the long run is gonna be expensive.. damn Flips!

Flashmn · 12-02-2003, 06:15 PM

Its not that bad once you learn how to slalom around... hey you probably havent seen these
http://www.middonaito.net/Videos/Flashsrolla ;D some vids me and my pal did over there

enjoy

Punisher · 12-02-2003, 06:53 PM

Eh.. Well the thing is.. my engine will start fine.. idle fine.. shut off fine (no dieseling).. but if I sit idle to long it will just start to climb and overheat till basically the radiator water is bubbling out of the over-flow res from the radiator...

As long as I am driving though there is enough air flow to keep the radiator cool.. keep the temp normal.. Whether the engine is cold.. at temp.. or HOT.. I get the same WOT response.. at first it's like ugh ugh gonna die... VROOOOOOM!!! weird crap..

So I think tomorrow or as soon as I am done finishing my interior work I am going to slap a new thermostat in there..
Maybe there is an air bubble right over the thermostat that is keeping it from reading right.. or something idk..
What is the easiest/best way to flush the engine/radiator of the coolant and re-fill the system with out having air locks?