Hesitation update
06-22-2003, 05:35 PM
#16
Rennlist Member
Hi Thomas,
The air temp sensor in the air filter box is not the main source of temp for the ECU. It uses engine temp (water temp) from Temp sensor 2.
It's not the MAF you would trick, but the ECU.
You can borrow a MAF on sale or return if you want.
The air temp sensor in the air filter box is not the main source of temp for the ECU. It uses engine temp (water temp) from Temp sensor 2.
It's not the MAF you would trick, but the ECU.
You can borrow a MAF on sale or return if you want.
06-22-2003, 06:50 PM
#17
Hi John
The sensor with a brown and a red cable in a plug, both connectors have about 1kOhm to ground. Is one of them the temperature sensor for the ECU? If I disconnect obviously the engine barely runs (except at idle speed). What should the exact resistances be?
The one with 2 yellow-blue cables (spade connectors) is probably just for the dashboard temperature gauge, since it doesn't read if I disconnect it?
Somewhere on this board I read the temperature sensor for the ECU should have a grey plug and a single yellow wire going to it, just I cannot find that one (or is that one for a different model year?) ..
It is just I really want to fix everything 'easy' first.
Cheers Thomas
The sensor with a brown and a red cable in a plug, both connectors have about 1kOhm to ground. Is one of them the temperature sensor for the ECU? If I disconnect obviously the engine barely runs (except at idle speed). What should the exact resistances be?
The one with 2 yellow-blue cables (spade connectors) is probably just for the dashboard temperature gauge, since it doesn't read if I disconnect it?
Somewhere on this board I read the temperature sensor for the ECU should have a grey plug and a single yellow wire going to it, just I cannot find that one (or is that one for a different model year?) ..
It is just I really want to fix everything 'easy' first.
Cheers Thomas
06-22-2003, 09:12 PM
#18
Burning Brakes
Join Date: May 2001
Location: Santa Cruz, California
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Hey, if you're tach is flaky, maybe the fuel relay is the culprit. The tach signal comes thru the relay and could be showing you on/off/on/off... and the engine is starving. Perhaps.
06-23-2003, 06:56 AM
#20
Rennlist Member
Thomas said - "The sensor with a brown and a red cable in a plug, both connectors have about 1kOhm to ground. Is one of them the temperature sensor for the ECU? If I disconnect obviously the engine barely runs (except at idle speed). What should the exact resistances be?"
>>>>>>>>>>>>
Hi Thomas,
Temp sensor 2 (with a Bosch plug, on the thermostat housing) is a double NTC resistor. One feeds the fuel ECU, the other the EZK ECU.
You measure each pin to ground, as you have done.
At 15 to 30 deg C, they chould measure in the range 1.4 to 3.8k ohms.
At 40 degC, 0.9 to 1.3k
At 60 deg C, 480 to 720 ohms
At 80 deg C, 250 to 390 ohms.
The one with 2 yellow-blue cables (spade connectors) is probably just for the dashboard temperature gauge, since it doesn't read if I disconnect it?
>>>>>>>> this one is positioned just behind temp sensor 2, and has the spade terminals (rather than a Bosch Jetronic plug, like temp sensor 2)
You are correct, it's for the dash temp gauge
From the measurment you have made, it sounds as though temp senor 2 is OK on your car. They usuallly fail open or short.
The colours on my car ('86 S2) are different to yours - my temp sensor 2 has green and greenred leads, the plug housing is Blue.
Hope this helps.
>>>>>>>>>>>>
Hi Thomas,
Temp sensor 2 (with a Bosch plug, on the thermostat housing) is a double NTC resistor. One feeds the fuel ECU, the other the EZK ECU.
You measure each pin to ground, as you have done.
At 15 to 30 deg C, they chould measure in the range 1.4 to 3.8k ohms.
At 40 degC, 0.9 to 1.3k
At 60 deg C, 480 to 720 ohms
At 80 deg C, 250 to 390 ohms.
The one with 2 yellow-blue cables (spade connectors) is probably just for the dashboard temperature gauge, since it doesn't read if I disconnect it?
>>>>>>>> this one is positioned just behind temp sensor 2, and has the spade terminals (rather than a Bosch Jetronic plug, like temp sensor 2)
You are correct, it's for the dash temp gauge
From the measurment you have made, it sounds as though temp senor 2 is OK on your car. They usuallly fail open or short.
The colours on my car ('86 S2) are different to yours - my temp sensor 2 has green and greenred leads, the plug housing is Blue.
Hope this helps.
07-01-2003, 12:04 PM
#21
Hi all
After sorting out all grounding and contacting problems and making the vacuum system tight I finally bought a refurbished MAF from John Speake and it really made a huge improvement, the hesitation is gone and the car seems to have much more power. I believe John is right saying that all MAFs finally go out of calibration due to age and use, so if you plan to keep your car for longer it is probably a good idea to buy a refurbished MAF at some point anyway (at least for cars which have got no oxygen-sensor involved in the fuel control like mine)
Cheers Thomas
After sorting out all grounding and contacting problems and making the vacuum system tight I finally bought a refurbished MAF from John Speake and it really made a huge improvement, the hesitation is gone and the car seems to have much more power. I believe John is right saying that all MAFs finally go out of calibration due to age and use, so if you plan to keep your car for longer it is probably a good idea to buy a refurbished MAF at some point anyway (at least for cars which have got no oxygen-sensor involved in the fuel control like mine)
Cheers Thomas
