Mechanics

'94 STUMBLES WHEN WARMED UP.

1994 Toyota Corolla

Hi. New to your forum, but what I've seen of it, it looks like a good place for competent answers.
OK. My daughter has a '94 Toyota Corolla, 1.6 liter, with 126621 miles on it. She left it home from school the other day so I could check it over. She told me it had been stalling out on her. I thought spark plugs, wires, etc. But when I took it for a test drive to replicate the situation, it was working great. Until it hit operating temperature. Then it started to stumble, hesitate, and almost stall, usually at dile and during acceleration. Apparently it has stalled on her several times. Everything 'looks' in order, and the " check engine" light is not on. I tried accessing the codes by jumping Te1 and E1 with a paper clip, and all I got was a constant blinking light. No codes, just a steady blink - blink - blink - blink. She just got home from school and told me that in the traffic jam trying to leave the parking lot it did stall on her a few times.
I really need to fix this. Any ideas?


Thanks,

Chris.
Avatar
Carmievg
September 21, 2007.




Two things come to mind, fuel pump, or ignition system, if either of these components fail the computer might miss it and say everthing is ok. Check the fuel pump and ignition module, we have repalced both on that car. If it dies only at idle, try checking for broken or cracked vacuum lines, inspect the air intake boot to the air filter, this can no tears in it,l next try servicing the throttle bore and IAC motor http://www.2carpros.com/how_to/how_to_tune_up.htm , if this dosnt help try replacing the idle air control motor. please let me know, thanks for visiting 2carpros.com

2CarPros Ken
Sep 21, 2007.
I appreciate the rapid response! But looking at your answer, I'm inclined to lean more towards the ignition aspect rather than the fuel pump. I can't imagine the fuel pump only malfunctioning at slower speeds; wouldn't such a thing be more likley to manifest itself at higher RPMs? And since it runs just fine when cold, which vacuum lines would be most likely be the culprits? As for the air intake boot, do you mean before the filter? Or do you mean the cover over the air filter and plastic tube which runs between the filter and the throttle body? The latter appears to be fully intact. And by " servicing", do you mean dismantle and clean? Or replace?

Thanks,

Chris.
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Tiny
Carmievg
Sep 21, 2007.
Yes, it does sound like ignition system, try a new set of plug wires and plugs, cap and rotor. On the air intake tube, check between the throttle body and the mass air flow sensor.

2CarPros Ken
Sep 25, 2007.
I talked with a neighbor, who is an instructor at the local Tech College in the diesel mechanics program, where the entire automotive/mechanical section is one big happy family, and he suggested something along the lines of the Mass Airflow System as well. I had expended about a half can of intake cleaner into the thing, but it made no difference. He also suggested I take it to a shop with the right equipment to properly diagnose the issue. : ( No sense in throwing parts at the car in a hit-or-miss attempt at repairs. On the bright side, he recommended a shop about two miles away, where the owner is a former student of his. They connected their machine to it, ran it till warm, and diagnosed the Air Flow Metering system as the culprit. They then " fogged" the intake, cleaning the top end of the engine, including the intake, throttle body, and cylinder heads. $300 later it runs like a champ. My daughter is tickled pink at the newfound " power" her Corolla 1.6 has, and I'm sure she will also see gains in fuel effiiciency. He also suggested new cap, wires, plugs, etc. That's what Saturdays are made for. ; )

Again, I thank you for your input, and rest assured I will be looking to this forum again if the need arises.

Chris.

Tiny
Carmievg
Sep 28, 2007.

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