Gradual Power Loss Until Stall

[Chrali]

My Volvo's been on the drive long enough for the battery to be dead, so I've charged it up. I posted before that once in a blue moon, the car gradually lost power over several seconds until it stalled, despite my foot full on the throttle. It would take several minutes to cough into life, and would catch but not stay running.

Now I used to have a cutting out at roundabouts as if the ignition was turned off and replaced the CPS, FI and FSR relays and that cured that problem, so this gradual power loss scenario is a new one.

I've checked the FPR and no fuel is leaking to the inlet, so I assume the FPR is good.

Its happened twice, once when the car was cold and once hot so temperature doesn't seem to be a factor.

So has anyone else had this gradual loss of power until stall and if so what fixed it.

[Chrali]

Found this on a US site. . . . .

Number 2 is exactly the scenario, low power then nailing it!!!!! I guess they're talking about the ignition amp.

PFV price is £50 Volvo is £150.

Is it worth getting the PFV one, or is there an OE part cheaper?


Engine Stalling

1.One common cause of stalling is vacuum leaks. Check all vacuum hoses and fittings including all large hoses. If your Volvo is equipped with emissions equipment such as a charcoal evaporative canister, the end of the hoses sometimes crack over time creating a vacuum leak.

2.Stalling can also be caused by an erratic Fuel Control Module. Note: On some vehicles this is called the Electronic Control Module. This might be indicated if the motor almost stalls when you accelerate from a stop and then suddenly slams up to full power.

[volvoz2000]

I would say they are talking about the ECU not the ignition amp... AMM could be the cause... it doesn't look like you have changed that yet?

[Chrali]

Not cheap items those. Can AMM cause gradual loss of power until stall? The lambda light wasnt on.

I want to stay with proven causes for this scenario to ensure I spend the cash in the right place.

[FullEnglish]

A bad AMM can cause loss of power, in my experience it was fairly on/off an lowered the revs at idle to 3 or 400 rpm. Lambda light will only show if the computer logs a fault code that relates to emissions. Have you read the fault codes recently?

[ASt85]

I had a similar problem with my father's old Mondeo - 16 years old and a genuine 30K on the clock - covered <100miles in its last 6 years to MOT & back at Ford main dealer - turned out to be a choked Catalytic convertor - cured with an after market Cat costing around £45 + VAT if memory serves. Though must admit power loss was progressive to stall point and rapidly apparent on climbing hills however slight and on attempted acceleration!
Might not be relevant, but worth checking.
Cheers
Alan

[Mr Sam]

is the car turbo?

ive heard a blown recirculation valve can cause the car to die

cheack vacuum lines too including the one to the fuel pressure regulator

the temperature sensor just under the manifold is worh a try ive just changed mine and the car idles loads better .... the idle control valve takes a feed off this




also with AMM's i would assume you can clean them like ford ones i have noticed volvo ones have a metal gauze over them which im sure can be removed them clean the contact wires very carefully with something that wont leave dust on them ..... and dont break them!!

[Chrali]

My dad made me the code reader, but what is the button for? Do I have to do the same as the FAQ for the underbonnet diags such as pressing the button for various numbers of seconds?
Might mean nothing as the battery had gone flat, so would it have lost the codes? I seemed to get 1-1-1, but wondered if I've wiped the fault codes?