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roger,
i'm having an issue with my 98 s70 non-turbo stalling right after i start it. it starts up, idles for a few seconds then starts to drop rpms spit sputter rpm may climb again then it'll stall. occasionally, i'll get a backfire with a puff of white fumes that comes from the intake. i've tried unplugging the MAF and starting it cause i heard this will isolate a bad MAF. i've replaced the plugs, wires, distributor, and rotor. tested the coil, TPS, cam position sensor, all are good. the idle control value vibrates when the key is on, but i read that this is normal. i know i'm getting fuel. i've checked the fuel pressure at the pressure connector after the stall and fuel squirts out, so i know it's not a fuel pump or relay issue. i'm also getting good spark. any help would be greatly appreciated
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mike, what happened after you unplugged the MAF? did it surge? What did it do when you plugged it back in? Roger
roger,
thanks for the quick response. nothing much changed, if i had the MAF plugged in or not. i cleaned the throttle body, it was pretty dirty. i also cleaned the gunk out of the idle control value with the cleaner, and cleaned the vacume lines etc. i've also replaced the throttle position sensor. i was able to get it to run for about 90 seconds giving it a little bit of gas, say 1500 rpms. eventially though it cut out and died again. i have the ability to hook the OBCII to my laptop, but i'm not getting any codes. the odd think is the check engine light is on though. i must say, this is the first problem that i've had with the car and it has 125k miles on it. i don't mind spending the time/money, she's been good to me. again, thanks so much for the help. it's not easy being a do it yourselfer.
mike
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Mike, whats the fuel pressure reading at? These cars have fuel pump issues sometimes. I wish the MAF wasnt so expensive. I would have you go there first. Roger
roger,
i didn't check the specific pressure, i only know that fuel squirts out of the pressure connector both before and after the stall without attempting a restart. i read that the pump works when the ignition is in position 3, and if there is pressure in the line after a stall it's not the fuel pump. i'm assuming you feel i should check the pressure? also, i used a diy repair manual and tested the MAF using an electrical tester, and it appeared to be fine. if you think i should replace the MAF, i don't mind the cost. i have no plans on replacing the car anytime soon, so i'm sure it'll wear out eventially anyway. one other question, is there a way to have the computer checked at a dealership? didn't know if they had a way to hook it up and see if it's functioning properly.
AnswerMike, on that system, a scan isnt going to do much except if a code was stored and you said there wasnt so I wouldnt waste my time. Yeah, the fuel pressure would be nice, then you can check to see if you are losing pressure right away. If all checks out then I would have a Volvo shop check it out. Its very hard to diagnose these sort of problems like this. Roger
