hello, my 850 nonturbo has recently (up till now) been stalling everytime i came to a stop. the check engine light came on, and it said that it needed a new crankshaft sensor, it lied. the sensor had already been replaced. so then i continued to replace the throttle position sensor, then the idol sensor (i think thats what its called, its silver, round, with 2 tubes coming out of it). after all that it just stopped starting all together so i purchased a new fuel pump relay, which also wasnt it. so i ordered a new camshaft (hoping this will fix it) which came in today im about to go install it.

my question is if this dosent fix it, what else could it be? the Air Mass FLow sensor? maybe it needs a new fuel pump which im hoping isnt it cause buying the new relay was the last of my money. im a college student (with of course no money) and i really really need this freakin thing to run.

please can someone help me please?

I'm more inclined to think that the culprit is the Air Mass Flow sensor, ie, assuming you've fuel going into the cylinders. If it's the fuel pump, it will hardly give you any symtoms that it's failing - in my experience.

Good luck.

well i put in the camshaft, and as i thought it didnt do anything. the air mass flow sensor looks to be new but i guess i can try and replce it since i dont have any other ideas of what it could be. there is fuel going to the cylinders, if its the right pressure, i dont know since my pressure reader thing doesnt want to fit on my volvo (it fits on everyother car tho, go figure).


anywasy i have a list of things that i think can also being causing this problem:
-engine temp sensor
-dirty/bad MAF sensor
-oxygen sensor
-thermostat
-EVAP Valve (where is it and what does it do?)
-throttle butterfly (where is that and what does that do?)

if htere is anything you think i could have missed, please let me kno. and also if there is anything on this list you think could NOT be causing this "issue", i would also like to know that aswell.

thank you for your help.:)

so your telling me that the Air Mass Flow sensor could account for why the volvo was only stalling and now its not starting at all?

what is the best way to check if the fuel pump is not working?

Apparently, there are many things that can happen.

Have you checked everything on the pinned topic?

Somethings you DONT need to replace rightaway. You can just CLEAN them first for now. THings like the O2 sensor, MAF sensor, the Idle Air Control Valve, the throttle-butterfly are all cleanable. Unless real damage is evident.

and how would i go about cleaning them?

to noleander, about your question about the fuel pump, turn the key to pos 2 (dash-lights are on, not engine) you should hear the fuel pump whirring in the background. if you don't, it's the pump. clean the maf with carb degreaser. best way is with gasoline, but with the degreaser it's less likely to blow up :grin: good luck and keep us posted. also, was wondering why you thought it was the camshaft. and why the thermostat? are you running hot? when it does run, did it run rough? you didn't mention that. pcv? flamtrap?

For the MAF sensor, i use the Air-Sensor Cleaner. There's one by CRC. If you cant find any, you can try any aerosol-type contact-cleaners. Just spray the contact areas pretty good, but DONT TOUCH the inner parts. Just SPRAY it good and let it air-dry, in a non dusty area.

For the O2 sensor, i dipped it in Petrol (Gas) and leave it there for some time, all the time shaking it a bit to get the dirt on the sensor tip to loosen out. Run a search, i've posted photos on this already.

For the Idle Air Controller Valve, you can use Carb-Cleaner. I've used STP, Permatex, a few other brands. They can all work. One time, i was desperate, i used Spirits, and blowed it in using an air-gun. That was REALLY fun, but it didnt last somehow. Heheh.

The Throttle-butterfly, you can also use the Carb-cleaner.

well everyone, its been fixed.
turns out the bell housing bolt where loos and some were not even there. since there was this problem, the casing was seperated from the engine, and the inards exposed acting as an antenna and atracting the signales from the crankshaft thus throwing off the computer causing it to stall.
isnt that wierd? well its been succesfully rebolted and now it runs and drives fine.
thanks everyone for your input.

Wow, never heard that one before.

Thanks for the update!