Setting TPS to spec. Only reads "4.74 ohms" Help?
11-28-12, 05:07 PM
#16
From what I can remember, it was really hard to get it right, cause it was so sensitive, like you gotta move it really really steady and slow, cause a tad of rotation really gets it way out of spec. Like I said, it took me a few tries to get it right and a few months to get me to be really patient with it.
11-29-12, 11:01 AM
#21
I hope I have finally got it.
First of all, KingPhilip was correct; it doesn't make a difference if your key is in the "On" position in the ignition system. I ditched the key and did it without the ignition on and it worked just fine.
the first image is one of the thing's I wasn't understanding. I was checking resistance with VC and E2, when I was supposed to be checking resistance with IDL and E2. Secondly, the other thing I wasn't understanding was the real throttle stop screw. There were 3 different one's I located. I attempted all but the right one. (isn't that's how it goes any time?
) Kudos to this DIY. http://www.lexls.com/tutorials/EFI/tps.html Though it doesn't mention using a computer connector to check resistance, it is what made me grasp what i was supposed to do. (I didn't have a computer connector that would have fit the TPS, but i did have an old TPS harness.) Stripped all of the wires and used that. A lot easier than pulling out the whole throttle body IMO. Both images below are the two thing's I wasn't understanding. Will be test driving it soon. Will tell you how it goes! 
First of all, KingPhilip was correct; it doesn't make a difference if your key is in the "On" position in the ignition system. I ditched the key and did it without the ignition on and it worked just fine.
the first image is one of the thing's I wasn't understanding. I was checking resistance with VC and E2, when I was supposed to be checking resistance with IDL and E2. Secondly, the other thing I wasn't understanding was the real throttle stop screw. There were 3 different one's I located. I attempted all but the right one. (isn't that's how it goes any time?
) Kudos to this DIY. http://www.lexls.com/tutorials/EFI/tps.html Though it doesn't mention using a computer connector to check resistance, it is what made me grasp what i was supposed to do. (I didn't have a computer connector that would have fit the TPS, but i did have an old TPS harness.) Stripped all of the wires and used that. A lot easier than pulling out the whole throttle body IMO. Both images below are the two thing's I wasn't understanding. Will be test driving it soon. Will tell you how it goes!
12-01-12, 01:08 PM
#22
OK, so the problem arises again. I set the TPS exactly to spec, the same way the DIY here on CL said, and so I test drove it. Leaving out for about 20 minutes...no poor idle, no rough acceleration, nothing bad. As soon as the car got up to temp though it starting bucking and kicking, like what I replaced the TPS for way back when. I mean BUCKING and KICKING really hard, but randomly like usual. I set the TPS EXACTLY to spec, and made sure there was continuity, but now the evil symptom turns up again. The cat's ARE clogged up with crap and there is powerr loss from that, but now the car is worse than when I purchased it. It BUCKS. It KICKS. It idles like crap. It has less power than when I started with it...Please Help.
(BTW, I've cleaned the MAF (correctly), the IACV, The throttle body, New TPS, ran injector cleaner through it a lot, 1 SMALL vacuum leak I know of, coming of the EGR modulator, but it's been there since the problem didn't exist, and the spark plugs and wires are new. Anyone knows what's going on???)
(BTW, I've cleaned the MAF (correctly), the IACV, The throttle body, New TPS, ran injector cleaner through it a lot, 1 SMALL vacuum leak I know of, coming of the EGR modulator, but it's been there since the problem didn't exist, and the spark plugs and wires are new. Anyone knows what's going on???)
12-01-12, 01:24 PM
#23
Well, if you're saying that you've set the TPS to spec, congratulations you've just eliminated it as the problem. It's time to check on the EGR. I've never dealt with EGR on mine, so I can't really speak from experience. But bucking and kicking sounds a lot like EGR or shot catalitic converter, which is a very important part of the entire combustion, I just hope you don't have a blown head gasket.
12-01-12, 03:04 PM
#24
Well, if you're saying that you've set the TPS to spec, congratulations you've just eliminated it as the problem. It's time to check on the EGR. I've never dealt with EGR on mine, so I can't really speak from experience. But bucking and kicking sounds a lot like EGR or shot catalitic converter, which is a very important part of the entire combustion, I just hope you don't have a blown head gasket.
Just kinda frustrating, but it's for a reason. Anyway, It's not the head gaskets because the bucking, kicking and rough idle is only intermittent, if it was the head gaskets, it would run a lot worse. The Catalytic converter is SHOT! It's clogged and exhaust is coming through it at the seam, I can feel the warm air spitting out. The car is strong under throttle, but when there is little throttle applied, it run's rough, but only 1/2 the time. It buck's and kicks, but rarely. I think I will replace the cats now! Thanks for the help!
fix still in progress...will tell you if the cats were the problem.
12-10-12, 10:59 AM
#27
So I got the Y-pipe and sub-catalytic converter (if vehicle was sold in CAL) setup completely out from the SC400 and it is in the garage. Went under the car and visually inspected the cats. Both had about an inch and a half or so of deteriorated honeycomb metal. So we drove it with open headers. It was noisy. It was Awesome, but it was slower. With just the cats in there it was slower accelerating than with the entire exhaust system.. I will be leaving the cat's there, (you could see through the honeycomb) and replacing the front O2 sensors. I also got some gaskets for the Y-piping and exhaust. The old one's were rusty and burnt.
FYI: Setting the TPS to spec for the most part fixed the slight thump I was having under light throttle. Still not perfect but improved...
FYI: Setting the TPS to spec for the most part fixed the slight thump I was having under light throttle. Still not perfect but improved...
12-15-12, 12:19 PM
#28
So I finally got to get the exhaust back up into the car. Prior to that though, got the bank 1 o2 sensors out, then the $188 worth of O2 sensors back in.
The result:
-No bucking and surging
-No rough idle
-No acceleration bogginess
-almost no "running lean" exhaust smell
Though the oxygen sensors corrected the issues I was experiencing, there are still a couple flaws I would like the correct.
-Idle is too high
-Slight exhaust smell known as the "running lean" smell (crack in the weld on the sub-catalytic converter)
-No matter how long the engine is running, the tempeture does not exceed the "middle" zone on the gauge. (The thermostat)
Regardless of the issues this car has been running into, I still like it a lot and know it's just the additude it has from living outdoors.
So what could cause the high idle? Even adjusted the TPS to spec at one point and it is still at 1200 RPM at idle. Not a big issue though...
The result:
-No bucking and surging
-No rough idle
-No acceleration bogginess
-almost no "running lean" exhaust smell
Though the oxygen sensors corrected the issues I was experiencing, there are still a couple flaws I would like the correct.
-Idle is too high
-Slight exhaust smell known as the "running lean" smell (crack in the weld on the sub-catalytic converter)
-No matter how long the engine is running, the tempeture does not exceed the "middle" zone on the gauge. (The thermostat)
Regardless of the issues this car has been running into, I still like it a lot and know it's just the additude it has from living outdoors.
So what could cause the high idle? Even adjusted the TPS to spec at one point and it is still at 1200 RPM at idle. Not a big issue though...
12-17-12, 05:34 PM
#29
Your ISC may not be working fully and can't lower the rpms any further. I bought a used one with good results.
Why would you say the temp gauge not going past the middle is a bad thing? That's precisely what you want it to do. Anything else would indicate a problem.
Why would you say the temp gauge not going past the middle is a bad thing? That's precisely what you want it to do. Anything else would indicate a problem.
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