Bad Tps/iac? Bad/semi-erratic Idle, Running Very Rich; Window Motor Won't Connect To Gear

Nick94657

New Member
Jan 26, 2017
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So I've been putting off this thread for a while trying to run the erratic idle checklist among checking other sensors. I'd just like to confirm my suspicions before spending hundreds seeing as I'm sort of a newb to the engine/electrical components. I think I've narrowed it down to IAC/TPS. It's not throwing any codes relating to those however.

Symptoms:
-Sometimes it idles just fine and sometimes it won't. It seems to be fine if it's been sitting for a while and has cooled down. One of these days it almost wouldn't even crank.
-20mpg on average but seeing as I used to get around 23-25 on my route to work it's a significant drop.
-Runs very rich. It's gotten better since I've fixed/cleaned a few things but it used to be so bad I almost couldn't sit still in traffic without gasping for air.

Things I've determined:
-The ECT seems to be within range for resistance. Hadn't bothered checking voltage across the sensor as the wire itself is only getting 4.63 volts. I have not probed around for the cause yet but it's lower on my list of priorities now as I had a thread pulled up and some diagrams to test the cause of the low voltage.
-The IAC has a resistance of 10.1 volts going across it and is not throwing any codes, however switching polarity it seems to read the same resistance. I read it should read open or a very high resistance?
-The TPS voltage is reading anywhere from .4v to 3.5v, however they are completely reversed. The reference voltage is solid at 5v so that's fine. At idle it reads 3.5v or so and at WOT it reads .4v. I'm not reading anything on the reversed voltages being a bad TPS so...?



Also I've been struggling with the window motor on the passenger side. I removed the old one no problem but when I went to install the new one it simply would not mesh with the gears. I had it replaced before because of the bad bushings but it stopped going down randomly. Is there a trick to get it turned in right? I called a 'ASE certified tech' and he said I needed to drill or retap the threads yet I'm using the same hardware that came off it.
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
Not sure about the window motor problem, you should be able to jiggle the window a little to engage the teeth. Never had that problem and I've changed many.
Test the sensor that is mounted to the heater hose tube on the passenger side of intake. Can't remember what its called.
Ect?
 

Nick94657

New Member
Jan 26, 2017
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Not sure about the window motor problem, you should be able to jiggle the window a little to engage the teeth. Never had that problem and I've changed many.
Test the sensor that is mounted to the heater hose tube on the passenger side of intake. Can't remember what its called.
Ect?
Yes That's the ECT. I've tested it and it's fine.

How many miles? Setup? Could be a few things...
The dash that came in it is supposedly from a Cobra. IDK how much I trust the original owner so that dash reads 306k. Has an e303 cam and Cobra upper/lower.
 

akaNYr

Member
Jun 13, 2017
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Washington state
Damn I wish I got 20mpg....I'd be happy! I get between 13.5 and 15.5mpg. My car starts up with a healthy roar and has a good passing speed. I got a new distributor cap, cleaned the MAS, the TBS inside and out, replaced the fuel filter and pump. That got me an almost steady 15mpg! Not to mention a prior owner put in one of those high priced chrome cold air induction units.
 

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