Corsa 1.6i sensor problems

Z

Zakhele001

Active Member
Joined
Jun 30, 2022
Messages
69
Reaction score
17
Sensor original harness colour code

My Corsa 1.6i sport ( c16se ) 8v SOHC has problems with idling sensor and MAP sensor. I recently bought it as a used car. I have over overhauled it but it is idling rough. Connecting or disconnecting the IAC sensor has no impact on the idle and connecting the MAP sensor stalls the engine immediately.
I see that someone has been there. The sensor connectors have been soldered so I resolved to start by getting new sensors and their connectors. Unfortunately I cant find the original harness color code on google hence i just followed what I found and connected my new sensors and connectors following what I found.
I need someone who can help with where each wire goes. e.g the MAP sensor next to ne water bottle has 3 wires ( original harness wires ) - Green, Black with white stripe and Brown with green stripe. My after market connectors have their own colors but what i wanna know is, when this connector is plugged in i.e. with the clamp up and I'm standing in front of the car facing it. Starting from left which wire goes in first. I don't even know what each wire does.
Also on the IAC sensor starting from the left what is the order of the colours. On this one, the original harness wires are 4 i.e., blue, green and two greens with stripes.

Thanks.
 
Zakhele001 said:
Thanks. You always go out of your way to help.View attachment 1352854View attachment 1352856View attachment 1352858
Click to expand...
Okay, the Map is wired correctly, the tricky one is the IAC, because it seems to have two white greens on it, as you are looking at the connector, there is a white/green on the left, another white green on the far right. Solid green just after the white green on the left and blue thereafter, so starting from the left, white/green, green, blue and white green, you will just take a chance on the white/greens because they are even equal in size.

Maybe will check again and see what difference there is.
 
TheChamp said:
Okay, the Map is wired correctly, the tricky one is the IAC, because it seems to have two white greens on it, as you are looking at the connector, there is a white/green on the left, another white green on the far right. Solid green just after the white green on the left and blue thereafter, so starting from the left, white/green, green, blue and white green, you will just take a chance on the white/greens because they are even equal in size.

Maybe will check again and see what difference there is.
Click to expand...
Thanks. My main issue ( IAC) was with those white-green. They had been put in the centre. When I came to clean them up I thought one had a yellow line and the other had a white line only to realize that they are identical after cleaning. Though I had taken the pics, I got stuck on which one was which. They had been put wrongly after all coz even switching them around did not change anything. Will play around and update.
 
Front.jpg

It's looking good, the upgraded battery wiring is impressive, did you that yourself?

Still need to do mine, the original is such a mess that I wonder if Opel did it on purpose.
 
TheChamp said:
View attachment 1352968

It's looking good, the upgraded battery wiring is impressive, did you that yourself?

Still need to do mine, the original is such a mess that I wonder if Opel did it on purpose.
Click to expand...
Yes. I was battling with earthing and also my starter motor was heating up cables. The original Corsa battery harness was corroded.
The main starter and alternator wires (16mm) and those battery terminal clamps are from Outdoor Warehouse. Wires are R89.00 per meter and those clamps are R139.99 ( National Lunas ) each. They are quite cool and very practical. All these auto stores sell those clamps that don't allow you do connect other accessories directly to the battery and the way you clamp in the big cables fails every time.
I used to see them online through Takealot but these guys advertise things they cant guarantee if they can source within a reasonable time. Theirs also incorporated a quick release lever.
The 4x4 shop also has these clamps and other practical fittings. I would only get these from OutdoorWarehouse or the 4x4 shop as their quality is always good.
 
Zakhele001 said:
Yes. I was battling with earthing and also my starter motor was heating up cables. The original Corsa battery harness was corroded.
The main starter and alternator wires (16mm) and those battery terminal clamps are from Outdoor Warehouse. Wires are R89.00 per meter and those clamps are R139.99 ( National Lunas ) each. They are quite cool and very practical. All these auto stores sell those clamps that don't allow you do connect other accessories directly to the battery and the way you clamp in the big cables fails every time.
I used to see them online through Takealot but these guys advertise things they cant guarantee if they can source within a reasonable time. Theirs also incorporated a quick release lever.
The 4x4 shop also has these clamps and other practical fittings. I would only get these from OutdoorWarehouse or the 4x4 shop as their quality is always good.
Click to expand...
Thanks, I have to redo mine, the original wires are just too thin. What length were the wires? Will 1m be enough from starter to battery?
 
IAC valve issue sorted....!!! Big thanks to you. The green wires with a line, though I had put them outside, I had vice-versed them. Funny, one never guesses right. Of course, as per your illustration, the two middle wires were at wrong points. I had started with Black. No amount of switching around was going to work as there were just too many possible outcomes from four unknowns.!
Now with everything connected as per your illustration I can hear the suction now through the valve plunger. You can hear that the engine is idling through the bypass as the throttle is closed at idle.
I had to put an idling screw to push up the the throttle to open the throttle a bit. Now everything is controlled by the valve and sounds a lot better.
 
Zakhele001 said:
IAC valve issue sorted....!!! Big thanks to you. The green wires with a line, though I had put them outside, I had vice-versed them. Funny, one never guesses right. Of course, as per your illustration, the two middle wires were at wrong points. I had started with Black. No amount of switching around was going to work as there were just too many possible outcomes from four unknowns.!
Now with everything connected as per your illustration I can hear the suction now through the valve plunger. You can hear that the engine is idling through the bypass as the throttle is closed at idle.
I had to put an idling screw to push up the the throttle to open the throttle a bit. Now everything is controlled by the valve and sounds a lot better.
Click to expand...
What rpm is it idling at?
 
TheChamp said:
Thanks, I have to redo mine, the original wires are just too thin. What length were the wires? Will 1m be enough from starter to battery?
Click to expand...
Actually, I realized after I bought two meters that 1m would have been adequate but i wanted a descent cable play between the starter motor and alternator to try and avoid the hot engine and moving parts. I would go for 1.5 meters to be 100% sure but Outdoor only sells in full meters hence you are stuck with two meters. Motorlek sells in half meters.
I'd also suggest get their perfect fit lugs. I cramped them and also got their corresponding heat shrinks. I think those final sleeves were an overkill, but i couldn't risk anything scratching the cables and causing a short. There is a good room behind the engine but I would test fit the cable before cutting but you will never need more than 1.5m... Don't use the old harness to measure as the manufacture always tries to get the shortest he possible can.
 
Zakhele001 said:
Actually, I realized after I bought two meters that 1m would have been adequate but i wanted a descent cable play between the starter motor and alternator to try and avoid the hot engine and moving parts. I would go for 1.5 meters to be 100% sure but Outdoor only sells in full meters hence you are stuck with two meters. Motorlek sells in half meters.
I'd also suggest get their perfect fit lugs. I cramped them and also got their corresponding heat shrinks. I think those final sleeves were an overkill, but i couldn't risk anything scratching the cables and causing a short. There is a good room behind the engine but I would test fit the cable before cutting but you will never need more than 1.5m... Don't use the old harness to measure as the manufacture always tries to get the shortest he possible can.
Click to expand...
Lastly what kind of crimper do you have? I have been planning to buy one but want to make sure I get the right one because I have wasted a lot of money on useless tools.
 
TheChamp said:
Lastly what kind of crimper do you have? I have been planning to buy one but want to make sure I get the right one because I have wasted a lot of money on useless tools.
Click to expand...
I'm just like that and I'm trying to avoid the temptation. You don't need a crimper at all. I used a normal harmer for battery wires. The trick is to push the cable in very deep into the lug hole until you can see it on the little hole on the other side, then while holding in one hand push with the same palm while also pushing in with the fingers. Then gently evenly tap with the harmer ( hit at an angle of the as opposed to flattening), this is to secure it from sliding out. Now increase the hitting impact. The hard surface underneath should have a corner or edge to effect some dents or you can rely on the fact that you are using the harmer at an angle You should turn it around to make some dents also on the other side so that it holds better and looks balanced and not too much out of shape (... there is something about neatness). I don't want something that looks like a squashed potato. Let no-one fool you, this wont come out. I had disgruntled bush mechanic trying to pull it out without success.
As I like neatness, I had placed slightly larger heat shrinks on the cable before hand. They looked better than factory. The heat shrink nicely follows the the dents on the lug.
You have to use a slightly bigger heat shrink to accommodate the deformed lug. Another tip, you should keep an eye on that little hole to see that the cable does not move. I did about 8 lugs and the wire did not slide back. I think the tapping helped.
On all other none battery cables you use the normal side cutter. I was surprised how soft these were. You also start with small plier squeezes. Don't forget to turn the lug around so that it remains more or less straight. Now make a couple of deep dent lines on both sides and you are good to go.
Don't buy a heat gun. A cigarette lighter does a better job. Just have the flame on the heat shrink and keep on turning the wire or the lighter to suit your shape. The heat shrink wont burn unless you really want to burn it. It is not as sensitive as plastic as most people think.
The harmer crimper would cost you about R650.00 and the plier like crimper ( smaller cables ) another R350.00 yet they will do an identical job...!
 
TheChamp said:
What rpm is it idling at?
Click to expand...
Sorry another project...! The Rev counter is not working but thus an easy fix. I would guess it is at around 850 - 950. I've had these corsa lites for a million years. Those with idling issues, I used to cut the tip of the accelerator cable then make a loop and join the throttle to the accelerator cable with a cable tie. I would pull on the cable tie until I get the sound I want and on checking the rev counter I would be between 850 - 1000. On this one I had found an upside down screw hole which I had used inconjunction with the good cable tie but now with the working IAC I have taken these off. The disadvantage of screw or cable is that the idle sometimes falls a bit or increase maybe due weather or when filters are getting dirty then you will have to make a small adjustment but the sensor automatically adjusts and and compensates for any changes.
 
TheChamp said:
What rpm is it idling at?
Click to expand...
Now my next project is the MAP sensor. I don't understand why the engine cuts off immediately when I plug it in. As I said, the engine was overhauled and my cables were heating up when I tried to start. I had thought that I had too much compression. We resolved to pull with another car and it kick started with all the sensors connected but now I think with all the fiddling something changed. ( problem was not excessive compression or too tight clearances, the starter had burnt the "aperture - ?," hence pulling excessive power from the battery - melting the wires and even the battery terminals. Motolek gave me back my burnt part as a souvenir !!! now the starter motor turns so fast and the car starts even before the key reaches the end]
I think the car sounds almost ok compared to my 1.4 with a disconnected MAP. My 1.4 MAP sensor connecter had a broken locking clamp hence the connector would sometimes slide out and it would immediately sound like a car with faulty exhaust valves - "blowing air like sound" .
I can hear this sound on this one but it is really faint, I think the computer has managed well to compensate somehow. It is no longer running too rich like before. Spark plugs look ok even after a prolonged idle.
 
Zakhele001 said:
Now my next project is the MAP sensor. I don't understand why the engine cuts off immediately when I plug it in. As I said, the engine was overhauled and my cables were heating up when I tried to start. I had thought that I had too much compression. We resolved to pull with another car and it kick started with all the sensors connected but now I think with all the fiddling something changed. ( problem was not excessive compression or too tight clearances, the starter had burnt the "aperture - ?," hence pulling excessive power from the battery - melting the wires and even the battery terminals. Motolek gave me back my burnt part as a souvenir !!! now the starter motor turns so fast and the car starts even before the key reaches the end]
I think the car sounds almost ok compared to my 1.4 with a disconnected MAP. My 1.4 MAP sensor connecter had a broken locking clamp hence the connector would sometimes slide out and it would immediately sound like a car with faulty exhaust valves - "blowing air like sound" .
I can hear this sound on this one but it is really faint, I think the computer has managed well to compensate somehow. It is no longer running too rich like before. Spark plugs look ok even after a prolonged idle.
Click to expand...
I forgot to mention that I bought an after market MAP sensor and it does exactly like the GM one I had thought was broken. Somehow I still suspect that even this new sensor is faulty because while using the other sensor to keep the intake vacuum line closed, connecting the free sensor cuts the engine immediately. I was thinking, that since the vacuum on the intake and the atmospheric pressure are different, the reaction should be a bit different ???
I saw one guy on a 1minute Youtube video seeking help on this. The moment he connected his green plug the car died immediately just like mine. I wanna check if he has found the solution and I will make him my hero but if I find the solution first I will send him. I wanna be a hero also...!
 
What I found once, the connector at the sensor did not made contact with the wire. a resistor test proved that. I inserted a metal needle, problem sorted.
 
Zakhele001 said:
I forgot to mention that I bought an after market MAP sensor and it does exactly like the GM one I had thought was broken. Somehow I still suspect that even this new sensor is faulty because while using the other sensor to keep the intake vacuum line closed, connecting the free sensor cuts the engine immediately. I was thinking, that since the vacuum on the intake and the atmospheric pressure are different, the reaction should be a bit different ???
I saw one guy on a 1minute Youtube video seeking help on this. The moment he connected his green plug the car died immediately just like mine. I wanna check if he has found the solution and I will make him my hero but if I find the solution first I will send him. I wanna be a hero also...!
Click to expand...
I think I made a mistake on the map sensor wiring and it could be your problem, it's black/white wire on the left, green in the middle and brown/green on the right.

Hopefully that sorts it out.
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X