Volvo 940 b230fd bogging down

megames940 · Jun 23rd, 2024, 18:38

I have a problem with my 944, i drive at 2000rpm but sometimes when i decelerate a little bit i feel a hard shock and the car goes to idle speed and if i accelerate a little bit the car has a shock again and goes high in the rpm. So basically i dont have control any over the car then. Anyone know what it can be because it is happening for almost a year now. I checked the fuel pressure regulator and it is not leaking so it seems that is not the problem.

TonyS9 · Jun 23rd, 2024, 21:25

Is it an automatic?

Sounds like an autobox problem rather than an engine problem, but I have little experience of autos.

In a manual if you stall it it seems like a shock.

megames940 · Jun 24th, 2024, 22:44

Its a manual but it happens while driving and the engine doesn’t stall it just goes back to idle rpm while im not letting go of the pedal

TonyS9 · Jun 25th, 2024, 01:12

That doesn't make any sense the engine can't just go back to idle when it is in gear. Is it coming out of gear?

I can't understand the symptom, are you leaving some important parts of this out like you are declutching?

Do you mean it chokes when you press the accelerator? In that case a weak spark might be happening, sometimes caused by oil in the distributor.

Another issue could be the crank sensor if the rev needle drops to zero during the problem. This does not represent the rpm, it just means there is no spark trigger. Ignition amp might also be suspect.

Does it ever not start?

megames940 · Jun 25th, 2024, 14:04

the clutch doesnt slip and im not pressing the clutch and it is in gear because it keeps driving but at idle rpm then. it sounds fine when im pressing the gas and it doesn't feel like im losing power. the needle never drops to zero and the car starts directly always. But it happens most of the time when i lift my foot a tiny bit of the gas.

TonyS9 · Yesterday, 23:20

You can’t be driving at 2000rpm, something goes wrong and engine suddenly goes to idle. The car has to slow down so the engine can idle, unless it's coming out of gear.

Have you checked the engine codes?

megames940 · Today, 14:51

Ye i checked the codes and its 1.1.1 in 2 and 6. But now im also having idling issues but the iac is working and clean and the fuel pressure regulators is not leaking and fuel pressure is fine

Jun 23rd, 2024, 18:38	#1
megames940 New Member Last Online: Today 14:51 Join Date: May 2024 Location: robertsfors	Volvo 940 b230fd bogging down I have a problem with my 944, i drive at 2000rpm but sometimes when i decelerate a little bit i feel a hard shock and the car goes to idle speed and if i accelerate a little bit the car has a shock again and goes high in the rpm. So basically i dont have control any over the car then. Anyone know what it can be because it is happening for almost a year now. I checked the fuel pressure regulator and it is not leaking so it seems that is not the problem.

Yesterday, 23:20	#6
TonyS9 Premier Member Last Online: Yesterday 23:31 Join Date: Jul 2009 Location: Holywood	You can’t be driving at 2000rpm, something goes wrong and engine suddenly goes to idle. The car has to slow down so the engine can idle, unless it's coming out of gear. Have you checked the engine codes? Last edited by TonyS9; Yesterday at 23:23.

Jun 23rd, 2024, 21:25	#2
TonyS9 Premier Member Last Online: Yesterday 23:31 Join Date: Jul 2009 Location: Holywood	Is it an automatic? Sounds like an autobox problem rather than an engine problem, but I have little experience of autos. In a manual if you stall it it seems like a shock.

Jun 24th, 2024, 22:44	#3
megames940 New Member Last Online: Today 14:51 Join Date: May 2024 Location: robertsfors	Its a manual but it happens while driving and the engine doesn’t stall it just goes back to idle rpm while im not letting go of the pedal

Jun 25th, 2024, 01:12	#4
TonyS9 Premier Member Last Online: Yesterday 23:31 Join Date: Jul 2009 Location: Holywood	That doesn't make any sense the engine can't just go back to idle when it is in gear. Is it coming out of gear? I can't understand the symptom, are you leaving some important parts of this out like you are declutching? Do you mean it chokes when you press the accelerator? In that case a weak spark might be happening, sometimes caused by oil in the distributor. Another issue could be the crank sensor if the rev needle drops to zero during the problem. This does not represent the rpm, it just means there is no spark trigger. Ignition amp might also be suspect. Does it ever not start?

Jun 25th, 2024, 14:04	#5
megames940 New Member Last Online: Today 14:51 Join Date: May 2024 Location: robertsfors	the clutch doesnt slip and im not pressing the clutch and it is in gear because it keeps driving but at idle rpm then. it sounds fine when im pressing the gas and it doesn't feel like im losing power. the needle never drops to zero and the car starts directly always. But it happens most of the time when i lift my foot a tiny bit of the gas.

Today, 14:51	#7
megames940 New Member Last Online: Today 14:51 Join Date: May 2024 Location: robertsfors	Ye i checked the codes and its 1.1.1 in 2 and 6. But now im also having idling issues but the iac is working and clean and the fuel pressure regulators is not leaking and fuel pressure is fine

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