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Hello everybody. I’ve been a long time youtube subscriber, really enjoy the vids! Today I am writing to you with a very specific problem that I have been trying to deal with for quite some time now. My car is a 1989 Opel Kadett E with a 1.6 i4 (C16NZ) the engine managment system is known as “GM Multec SPi”. It’s a single point injection engine, so it only has one injector. The problem is that when I first start the car, or it hasn’t been driven for some hours the idle would either stick at 1500RPM or would go all the way up to 3000 with the first touch of the throttle. So far, I have opened and cleaned the throttle body, inspected the idle control valve, altrough it was fine I replaced it just for good measure, replaced the coolant temp. sensor, took the wiring loom out and inspected it (had damage in TPS circuit), and finally the TPS sensor was replaced two times. During the summer the problem is mostly gone, but now its getting cold out and I really dont wanna see the 3000RPM idle when its -10 degrees outside during the first start of the day. I could really use some help because I’ve completely given up. Every once in a while the Check engine light would come on with a TPS error, botsh sensors that I have are tested and working. I tried replacing the ECU aslo – same result.
I am totaly lost. If someone has some suggestions, please help. I will take a video of the problem in case somebody is having a problem understanding (English is not my native language).
Thank you very much in advance!
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TBI. Check your throttle plate bushings. Seems common among most if not all GM TBI systems. I’ve replaced a few myself. Sometimes when it’s cold out the bushings shrink and will leak in air that the computer is not commanding.
Excuse me for the lame question, but what is a “TBI engine”? And also, I’m kinda confused where theese bushings might be. Here’s a picture of the engine(not mine, but the same), perhaps you can point them out?
I have changed the gaskets between the 2 sections of the throttle body. The only one I havent done is the intake manifold to cylinder head one. I tired spraying WD-40 around it and listening for idle change but with no result. Perhaps I should do it. I have taken a video and it behaved just like it normally does. No check engine light, just idling at 2000RPM, you could actually see it going back to normal after the last restart.
CLICK HEREThe TBI is throttle body injection. Its the injector on top of the throttle body. Reliable design. The throttle plate bushings are where the throttle blade pin that holds the plate in place goes through the throttle body. They are usually metal. Over time they can wear from throttle actuation. But that doesn’t seem like that’d be the issue from your video. I’d use brake cleaner or something flammable as wd40 doesn’t really do the trick in my experiences. Could be a vacuum leak but probably isn’t. Make sure your coolant temp sensor is working.
Thank you for the response. I will look into it. The gasket costs $2, so I should probably replace it just in case. Thinking of testing the gasket by heating up the manifold with hot air gun. Do you think it would work? Obviously, I cant heat the whole manifold, so I’m going to concentrate on the gasket only.
I had a quick look at some pictures of ’89 Kadetts, and to my eye, they look like a certain Korean Daewoo that was sold in North America for a few years as a Pontiac LeMans. Blasphemy.
If the engine in your car is Korean rather than true Opel, you might want to check out Daewoo when it comes to doing internet research on your car, or when buying parts. You might find some answers that won’t show up if you limit yourself to Opel.
Very good eye, Evil-i! The cars really do look the same, but it’s the other way round. Daewoo Nexia/Racer and Pontiac LeMans are built by license from GM. The original car is the Kadett. I don’t really know what kind of engines they are using, but every sensor I have replaced over the years had “Made in USA” stamped on it, so I’m guessing my engine is assembled in the US? Or at least they used American parts. 😆 😆
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