Occaisional high idle, jerky running, C/E light

JAFO

Registered User
This is making me crazy!
I don't know what's going on here. New plug wires, all are fine, so that's not it. I thought it was the MAF plug, which has been loose before due to a weak clip, but I zip tied that tight to test that theory. The light comes on, usually in the morning when it's cold. The light will come on, but it feels okay, but a little power loss. Then, the light goes off and it feels "bucky" with a quick loss of power, almost like it wants to backfire and at idle, it'll hold at around 1500 to 2000--but not always the same. If I stop, turn the car off and restart, it may be gone. Might not do it again for a day or so. I haven't made any changes or mod's lately. I do have the ProM 75mm MAF, chip, but that's all I think might affect anything. Those have been on for several months though, performing flawlessly. I did unplug the battery to reset the computer a few days ago. It ran fine for a couple of days.

A bad IAC wouldn't do this would it? It happens while driving.

Any ideas?
 
seems to me ur IAC is on its way out... mines did the same thing... well... pull up the codes with a code reader and see whats it trying to tell u. im leaning towards the bad IAC. You should get a new one DIRECTLY from FORD cuz the aftermarkets at AUTOZONE and KRAGEN are "not" build right. I have a AFTERMARKET IAC from PEP BOYS and sometimes my car IDLES high and i have to turn it off and turn it back on and it will idle normal. My other problem with the bad IAC is that if u punch it... the IDLE gets stuck at around 2000 -3000 and since im driving a AUTOMATIC its bad... so i have to pull over and shut it off and restart the car to get the idle to normal. I need to get the one from FORD.
 
So a bad IAC can affect running even when not at idle? The bogging usually starts while I'm on the gas, steady cruising, normally around 45 mph or so, any RPM.
I haven't needed a code puller until now, I'll have to pick something up.
 
Okay, got a code puller.
111 (fine)
118 ECT sensor. Haven't found much on that in a search. I'm assuming that's the sensor by the thermostat? It's always had a loose plug, but would that really be what makes the car run rough and buck like that?

Would a loose connection on that plug wire cause the same effect as a bad sensor?
 
The ECT is located on the intake manifold over by where the fuel lines connect to the engine. The one in the thermostat housing is for the gauge and its not the one youre interested in.

Can a loose plug or wire cause the bucking? Yes they can.
When the car bucks does the tach stop working?
 
No problem with the tach.
I'll have to get in there and fine where you're talking about, I can't picture it.
 
I hate to be dense, but is this it?

faeff95f.jpg


I assume I should still open the rad cap first, then just unplug/unscrew? Should I use teflon tape on all threads?

Thanks for the help.
 
Yes sir thats the ECT sensor. You can use teflon tape or teflon pipe dope on the threads. Remove the rad cap incase there is pressure in the system and unscrew the old sensor and install the new one.:)
 
Thanks, and for my next trick, I'll ask how to change a light bulb! :rolleyes:

Thanks again, I've been lucky so far and haven't had to do much the car all year.
 
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