help! What did I do wrong? Engine won't run

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Dec 13, 2001 | 04:27 PM

dtong_ck

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From: Toronto Canada

help! What did I do wrong? Engine won't run

I had a post early about engine hesitate when cold. But it start and run fine. Here is what happened. I took the IAT(intake air temperature sensor) for checking. Resistance go up and down alrtight with different heat settings. I also took the Air by pass solenoid valve beside the ,I think, Throttle postition Sensor. I clean the valve make sure it move. Ther are two 2-wire sensors near the thermostat.I took one sensor near the thermostat to check the resistance value and it seems good, but I don't know if it is the engine coolent sensor. I put everything back and when I first crank the engine, it won't run. If I press the gas pedal down a little bit and it start to run but not smooth. It stall when I release the pedal and it beep with the check engine light comes on.Looks like there is no idling at all. What did I do wrong? I forgot to disconnect the negative of the battery. Will it screw up the computer module?
My aeroster is 1990 4.o litre 2 wheel drive with electronic dashboard.

Dec 13, 2001 | 04:39 PM

aerocolorado

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help! What did I do wrong? Engine won't run

[updated:LAST EDITED ON 13-Dec-01 AT 05:41 PM (EST)]
"I clean the valve make sure it move. "

I suspect the throttle position sensor was damaged while cleaning or is not connected properly.

Dec 13, 2001 | 06:34 PM

dtong_ck

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From: Toronto Canada

help! What did I do wrong? Engine won't run

I took the valve out without touching the TPS because the valve housing is separated from the TPS. I just worked on my van a while ago and I found a ground wire came off. It is attached to the engine near one of the 2-wire sensor. I hook it to a good ground and try start the engine and it will run but I still need to press down the gas pedal a bit. however it run more smoothly than before. At one time I can have the engine idle on its own. But when I restart it, it seems not working again. I also found that the digital temperature gauge is not working; it works before. How can I find out ,of the two 2-wire sensors, which one is the temperature sending sensor and which one is the engine coolent sensor. Anywhere I can find a electrical drawing>
Thanks.

Dec 14, 2001 | 08:51 AM

Mikeman

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Joined: Apr 2000

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From: PNW

help! What did I do wrong? Engine won't run

On my van and my truck (both with 4.0), the engine coolant sensor is the one on the driver side on the lower intake manifold. The temp sender for the gage is toward the passenger side on the lower intake manifold.

Dec 14, 2001 | 03:21 PM

dtong_ck

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From: Toronto Canada

help! What did I do wrong? Engine won't run

Then I must have screw up the temperature sending circuit because I did unplug the connector. I tried to take out the sensor to check but it is blocked by the pipe going to the engine block. Now my temp gauge has the bottom 2 and top 2 segments lit up. Seem like a short circuit. I am sure the coolant sensor is okay. Now I will go ahead to check the Idle air control valve or TPS.
Thanks a lot.