B230FD Problems :)

[Volvo940GL]

Originally Posted by Laird Scooby

I don't know how else to say it, i don't speak Norwegian, but you can't keep throwing parts at it, whether they cost you anything or not.

You need to go through a diagnostic process and start somewhere and work methodically from that point until it looks like you've found the faulty component. Then change that one. If things improve, refit the old one and see if the fault comes back, if it does, good, you're 2/3 of the way there! You then refit the replacement part, reset the ECU by pulling fuse #1 and confirm the fault is fixed.

The only thing you'll get from swapping parts willy-nilly is a headache and possibly a big bill from whoever you're borrowing the parts from.

I’ll start at the tps. Measuring ohm on closed and open position. It should be .1-.2 closed and infinite on open? Or vice versa?

[Laird Scooby]

Originally Posted by Volvo940GL

I’ll start at the tps. Measuring ohm on closed and open position. It should be .1-.2 closed and infinite on open? Or vice versa?

Yes, correct.

[Volvo940GL]

Originally Posted by Laird Scooby

Yes, correct.

Is there any good website that shows a good wiring diagram for LH2.4 and specs info for each sensor and actuator voltage and ohm?

[Laird Scooby]

Originally Posted by Volvo940GL

Is there any good website that shows a good wiring diagram for LH2.4 and specs info for each sensor and actuator voltage and ohm?

Yes, but not all sensors etc are on the same one. What sensors are you after details for?

[Volvo940GL]

Originally Posted by Laird Scooby

Yes, but not all sensors etc are on the same one. What sensors are you after details for?

Coolant sensors, MAF, CPS, TPS, lambda.

[Laird Scooby]

Originally Posted by Volvo940GL

Coolant sensors, MAF, CPS, TPS, lambda.

Coolant sensor - ~2500 Ohms +/- 10% ish at 20C WRT earth - two pins in the body of the sensor, each has a sensor between it and the body of the sensor, under #2-3 inlet tracts on the head

CPS either works or doesn't, if you're getting a steady stream of sparks from the king lead during cranking, the CPS is working.

TPS is a microswitch, it's either 0 Ohms or open circuit when the throttle is in the idle position. Note that incorrect adjustment will alter whether it's open or closed.

Lambda should vary between about 0.1V to about 0.9V when hot and idling WRT 0V

MAF, i need to know the Bosch number (probably starts 0 280....) from your MAF as various different MAFs were fitted, the output pins were different and so were some voltages.

Rough rule of thumb is about 2V+/- 10% WRT 0V on a steady idle rising smoothly as the revs and therefore airflow increases.

It can be different depending exactly on which MAF you have though, as can the output pins!

[Volvo940GL]

Originally Posted by Laird Scooby

Coolant sensor - ~2500 Ohms +/- 10% ish at 20C WRT earth - two pins in the body of the sensor, each has a sensor between it and the body of the sensor, under #2-3 inlet tracts on the head

CPS either works or doesn't, if you're getting a steady stream of sparks from the king lead during cranking, the CPS is working.

TPS is a microswitch, it's either 0 Ohms or open circuit when the throttle is in the idle position. Note that incorrect adjustment will alter whether it's open or closed.

Lambda should vary between about 0.1V to about 0.9V when hot and idling WRT 0V

MAF, i need to know the Bosch number (probably starts 0 280....) from your MAF as various different MAFs were fitted, the output pins were different and so were some voltages.

Rough rule of thumb is about 2V+/- 10% WRT 0V on a steady idle rising smoothly as the revs and therefore airflow increases.

It can be different depending exactly on which MAF you have though, as can the output pins!

Thanks

It could be any of those you suggested. Those sensors That may cause my idle

[Volvo940GL]

Originally Posted by Laird Scooby

Coolant sensor - ~2500 Ohms +/- 10% ish at 20C WRT earth - two pins in the body of the sensor, each has a sensor between it and the body of the sensor, under #2-3 inlet tracts on the head

CPS either works or doesn't, if you're getting a steady stream of sparks from the king lead during cranking, the CPS is working.

TPS is a microswitch, it's either 0 Ohms or open circuit when the throttle is in the idle position. Note that incorrect adjustment will alter whether it's open or closed.

Lambda should vary between about 0.1V to about 0.9V when hot and idling WRT 0V

MAF, i need to know the Bosch number (probably starts 0 280....) from your MAF as various different MAFs were fitted, the output pins were different and so were some voltages.

Rough rule of thumb is about 2V+/- 10% WRT 0V on a steady idle rising smoothly as the revs and therefore airflow increases.

It can be different depending exactly on which MAF you have though, as can the output pins!

My tachometer shows 500rpm at idle when I turned on the heater for the rear window. When I turn off rear window heater, the tachometer jumps and the engine hesitates.

https://youtu.be/px9IV9iFzck

[Laird Scooby]

Originally Posted by Volvo940GL

My tachometer shows 500rpm at idle when I turned on the heater for the rear window. When I turn off rear window heater, the tachometer jumps and the engine hesitates.

https://youtu.be/px9IV9iFzck

Check your coil wiring. Also the earth on the coil bracket/mounting.

[Volvo940GL]

Originally Posted by Laird Scooby

Check your coil wiring. Also the earth on the coil bracket/mounting.

Sorry if I ask dumb questions only dumb answer and good questions.

What should the readings be? And whether the ground is bad or not? From where does those two cables go from? From the ignition key and the other to the battery? How do I know if it’s a bad earth?