Weird Electrical problem...

Deep6

Registered User
The other day was returning home from work and pulled into the driveway. The engine was idling at it's normal 700-800 rpm amount and I pressed the buttons to roll both of the windows up.


Well I held the buttons a little too long and the windows reached the top of their travel and stopped. But the extra resistance of the window motors caused the engines RPM to drop to 400-500rpm and it held there for about a second before the engine could catch up.

I repeated this several times applying the electrical load to the allready rolled up windows and it continued to drop the RPM each time.

The battery is new and in good shape, does this mean that it is time for a new alternator?
 
My first guess is your battery, have it load check. If your battery is ok try recharging it. Check all the battery terminal connection to insure they're not damaged, corroded, or otherwise unserviceable. The battery cable insulation tends to crack as the age as well (like mine), replacing soon.
 
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Another possibility is a sticky IAC. When they get gummed up they will not respond to changes quickly eeough.

Jeff
 
Thinking the IAC is a real possibility...

Yeah, I'm thinking the IAC too. Sometimes when the Fan comes on, the RPMs will drop quickly for a second and then the engine will "catch up". There have been other times when I have come to a stop at the light and the RPMs will drop for a second.

My SC mechanic specifically warned me of spraying throttle body cleaner on the TB even if the cleaner says it's "Safe" for coatings. He stated that the coating allows the throttle butterfly to seal the housing air tight. Even the tiniest of air leaks can mess with the air metering of a IAC.

There have been several times that I have used "safe" cleaners, think that could be my problem? Should I "clean" the IAC or just replace it for a new one? If I've chewed up the protective coating on the TB perhaps I should just get a new TB (bigger one too)....
 
I don't think there is a protective coating on the TB. You can pull it off and use TB cleaner and a Qtip to clean it, but be careful.

Jeff
 
What about?

If I just shoot the cleaner up the butterfly bypass hole? They say not to do it but...... :eek:
 
At this oint there is probably so much gunk in there that you are going to have to take it apart to clean it (if that is the problem). It won't hurt as long as it is TB cleaner (carb cleaner will melt the diaphragm).

Jeff
 
Deep6 said:
Yeah, I'm thinking the IAC too. Sometimes when the Fan comes on, the RPMs will drop quickly for a second and then the engine will "catch up". There have been other times when I have come to a stop at the light and the RPMs will drop for a second.

My SC mechanic specifically warned me of spraying throttle body cleaner on the TB even if the cleaner says it's "Safe" for coatings. He stated that the coating allows the throttle butterfly to seal the housing air tight. Even the tiniest of air leaks can mess with the air metering of a IAC.

There have been several times that I have used "safe" cleaners, think that could be my problem? Should I "clean" the IAC or just replace it for a new one? If I've chewed up the protective coating on the TB perhaps I should just get a new TB (bigger one too)....

You know now that you mention it, mine was doing the same exact thing when the fan kicked on and the windows issues but not as bad as yours. Not too long ago I pulled the entire intake and fuel injection system off and totally cleaned, resealed it and rewrapped the wire harnesses. I also pulled off my fuel injectors and installed new injector o-rings.

Before I reassembled it I removed the IAC and TPS from the TP and totally cleaned out the TB with TB cleaner. It was disgusting with crap and didn’t appear to be sealing when closed. When I reassembled it, I installed a new IAC because the old one was moist with some kind of liquid (I think it was TB fluid) so I didn’t trust it. I also did the TPS because I was getting a TPS code during KOEO after I reassembled the intake. When I got it totally assembled and debugged all the KOEO codes, I no longer have those idle glitches anymore. Maybe the IAC was bad on mine as well but it's hard to tell because I also sealed up the IC tubs with Teflon gaskets, installed new plugs and wires, a new bypass hose, TB and Bypass gasket, Cam Sensor, and a pulley set. I got those gaskets from tbird88. I highly recommend them. The Cam Sensor, IAC and TPS, I got from Rock Auto.

I really feel the difference now. It was totally worth the time I spent doing the job as My Motor runs like a top now with new found power and looks almost new.
 
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