High Idle problem solved
04-29-2016, 01:22 PM
#1
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Car: Camaro 89 RS Convertible
Engine: V8 305 TBI
Transmission: Auto Gearbox
High Idle problem solved
Hello.
After a lot of problems with my convertible ( https://www.thirdgen.org/forums/dfi-...aken-when.html ), I finished with a problem of idle too high which I was not able to solve.
I founded what was the problem and I want to share it with you, if someone meet the same problem. May be it will help you:
In fact my car ran well but I did'nt know. Wanting to check the sensors and to see why my tachometer was so hight (1600 rpm), I used WinAldl with a laptop and a cabl1 OBD1 ALDL USB(see photo). On the USB side of the cable, there is a jumper on the USB (see other photo). With this jumper, you can put normal mode, shorted A to B mode and 10 K Resistor mode. I read on manual shop that in 10 K Resistor mode, you have access at all the sensors, also I used that mode thinking that it was the best one to check the sensors. But in fact, this mode affect the parameters of the ECM!!!
(see photo)
It put closed loop, EST is advanced, P∕N restrict functions are disable, and the more important IAC valve controls engine idle to 1000 rpm!
And as my tachometer is not accurate, I had 1600 rpm!
I changed the jumper to normal mode and started the car. It idles at 600 rpm (aldl reading) like it ran before all my problems.
Since my problems, I never tried before to start the car without checking parameters with the lap top in 10K mode. Also idle was always too high. The solution was just to put the jumper in normal mode......
I founded by accident the explanations when I was looking for how to remove O2 sensor......! (see photo)
I hope my stupidity will help someone to avoid that problem of idle
Jean Luc
After a lot of problems with my convertible ( https://www.thirdgen.org/forums/dfi-...aken-when.html ), I finished with a problem of idle too high which I was not able to solve.
I founded what was the problem and I want to share it with you, if someone meet the same problem. May be it will help you:
In fact my car ran well but I did'nt know. Wanting to check the sensors and to see why my tachometer was so hight (1600 rpm), I used WinAldl with a laptop and a cabl1 OBD1 ALDL USB(see photo). On the USB side of the cable, there is a jumper on the USB (see other photo). With this jumper, you can put normal mode, shorted A to B mode and 10 K Resistor mode. I read on manual shop that in 10 K Resistor mode, you have access at all the sensors, also I used that mode thinking that it was the best one to check the sensors. But in fact, this mode affect the parameters of the ECM!!!
(see photo)It put closed loop, EST is advanced, P∕N restrict functions are disable, and the more important IAC valve controls engine idle to 1000 rpm!
And as my tachometer is not accurate, I had 1600 rpm!I changed the jumper to normal mode and started the car. It idles at 600 rpm (aldl reading) like it ran before all my problems.
Since my problems, I never tried before to start the car without checking parameters with the lap top in 10K mode. Also idle was always too high. The solution was just to put the jumper in normal mode......
I founded by accident the explanations when I was looking for how to remove O2 sensor......! (see photo)
I hope my stupidity will help someone to avoid that problem of idle
Jean Luc
04-30-2016, 10:34 AM
#2
Member
Re: High Idle problem solved
Wow, thx for sharing Jean. It reads like the ECM was left in 10K mode by accident? Good u found that before buying any parts.
Congrats.
Congrats.
05-01-2016, 10:58 AM
#3
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Car: Camaro 89 RS Convertible
Engine: V8 305 TBI
Transmission: Auto Gearbox
Re: High Idle problem solved
You welcome Cardo0. I put it in 10K mode willingly....... In fact I shouldn't put this mode to have an engine running well. Furthermore, I don't have more parameters from the sensors in this mode. All the sensor are read in mode normal. Also, unnecessary to use the 10K mode.
I did'nt buy any parts, because, all the sensors had the good values, also, I did'nt see why I should have change any? To be patient, helped me to find the problem, and saving money.
I hope this post will help some ones to avoid to loose a lot of time to solve a problem on the car which is not really a problem.......but a bad handling of the ALDL OBD1 cable.....
Jean Luc
I did'nt buy any parts, because, all the sensors had the good values, also, I did'nt see why I should have change any? To be patient, helped me to find the problem, and saving money.
I hope this post will help some ones to avoid to loose a lot of time to solve a problem on the car which is not really a problem.......but a bad handling of the ALDL OBD1 cable.....
Jean Luc
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