'97 850 T-5 acting very strange

WSparrow · Oct 21st, 2011, 03:33

Hi,

I have been trying to figure out this problem for about a week now with no luck. The car starts fine when it's cold, but when I put it in gear and give it some gas it stalls. In trying to fix it, I've discovered that if I let it sit and warm up for 5 or 10 minutes it will also stall in park, right about the time the engine gets up to normal temperature. At first I thought it was a weak fuel pump, so the pump and filter have been replaced. The fuel pump relay seems fine, it's the red one (which I'm told is better), I opened up the casing and there is no discoloration or cracked solder, it looks brand new.

The only OBD codes pointed to a misfire on cyl 4 so I replaced all the spark plugs. Now the problem is still there, but it's not giving any errors. I've replaced the air filter, bypassed the cat. converter, and checked every vacuum line I can get my hands on for leaks, but none of it has made any difference. I even called in a favor and had a mechanic friend spend 2 days on it. He's stumped too.

Any suggestions would sure be appreciated.

Thanks

p.s. When in gear, if I tap the gas a few times I can get the rpm to pick up slightly but not enough to properly drive it and steady pressure on the accelerator stalls it dead.

Chris_Rogers · Oct 21st, 2011, 10:16

Is the coolant temperature gauge behaving normally?

Have you checked the vacuum connection to the fuel pressure regulator on the fuel rail?

Have you checked the fuel pressure?

dgunthor · Oct 21st, 2011, 11:01

as above, i'd try replacing the coolant temperature sensor - had this issue with other cars and had issues with cold/warm start

david philips · Oct 21st, 2011, 11:56

pull the plug out of the maf and try it , if no better then thats ok. then you will have to look at the spark things like the rottor arm,try a timeing light on and see if the sparks fail when the engine cuts out ,if so it should rule out a fuel fault, then start pulling out one electrical plug at a time check for rot etc put it back and try, sorry i cannot think of any thing else at present. good luck.

The Hooded Claw · Oct 21st, 2011, 13:19

ALL good suggestions above ..... but from Experience i'd go for the Coolant Temp Sensor meself

What you describe is CLASSIC Coolant Temp Sensor Failure

Keith

WSparrow · Oct 21st, 2011, 20:17

Thanks for the replies. The fuel pressure and regulator, seem to be good. I've already checked out the maf and it looks brand new. I've only had the car a few months, and not sure what work has been done to it. But I suppose it couldn't hurt to try disconnecting it.

The rotor arm and timing are good, when the engine is cold or only partly warm I can get it up to 5000 rpm without it coughing or sputtering and since doing the spark plugs there are no more OBD codes (misfire or otherwise).

It hadn't occured to me that the temp sensor might be the problem. The temperature guage is working properly so I never gave it any thought. I'll see if I can get my hands on a working one to test it.

Thanks again, I'll let you know how it goes.

WSparrow · Oct 23rd, 2011, 19:05

Replaced the temp sensor and thermostat. No real change. It idles fine when hot now, but still tries to stall when I give it gas. I've found I can get it to accelerate if I just barely touch the pedal. It gradually picks up, but it at that rate it would take about 5km to get up to speed. I'm at a loss. I'm going to clean the injectors and see what happens when I disconnect the MAF, but might have to bite the bullet and take it to a volvo specialist.

Any other ideas before I do?

deathrider311271 · Oct 23rd, 2011, 19:16

when was the last time the fuel filter was replaced?

it sounds like an air leak somewhere to me, have u checked ALL the turbo pipes? inlet manifold? injector seals?

WSparrow · Oct 23rd, 2011, 20:07

The fuel filter and fuel pump were replaced last week (after the problem started). I've checked the turbo/vacuum lines as thoroughly as I can but many of them are hard to get at so there could be a pinhole somewhere, I just can't find it. If I hit the throttle while under the hood I can hear a sucking sound while it's trying to stall, but that seems to be coming from the air intake on top of the rad, so I don't think that's it.

Also, I did disconnect the MAF and fire it up. It made no difference, it just made the lambda light come on.

deathrider311271 · Oct 23rd, 2011, 20:22

spray some carb cleaner around the injectors and see if it tries to stall then, if so your injector seals are knackered. this happened to mine earlier this year

As for the MAF you need to disconect it while the engine is running, if nothing happens its broken

Oct 21st, 2011, 03:33	#1
WSparrow New Member Last Online: Mar 20th, 2012 01:21 Join Date: Oct 2011 Location: Vancouver	'97 850 T-5 acting very strange Hi, I have been trying to figure out this problem for about a week now with no luck. The car starts fine when it's cold, but when I put it in gear and give it some gas it stalls. In trying to fix it, I've discovered that if I let it sit and warm up for 5 or 10 minutes it will also stall in park, right about the time the engine gets up to normal temperature. At first I thought it was a weak fuel pump, so the pump and filter have been replaced. The fuel pump relay seems fine, it's the red one (which I'm told is better), I opened up the casing and there is no discoloration or cracked solder, it looks brand new. The only OBD codes pointed to a misfire on cyl 4 so I replaced all the spark plugs. Now the problem is still there, but it's not giving any errors. I've replaced the air filter, bypassed the cat. converter, and checked every vacuum line I can get my hands on for leaks, but none of it has made any difference. I even called in a favor and had a mechanic friend spend 2 days on it. He's stumped too. Any suggestions would sure be appreciated. Thanks p.s. When in gear, if I tap the gas a few times I can get the rpm to pick up slightly but not enough to properly drive it and steady pressure on the accelerator stalls it dead. Last edited by WSparrow; Oct 21st, 2011 at 03:36.

Oct 21st, 2011, 11:01	#3
dgunthor Senior Member Last Online: Sep 27th, 2022 13:38 Join Date: Nov 2009 Location: Caerphilly	as above, i'd try replacing the coolant temperature sensor - had this issue with other cars and had issues with cold/warm start __________________ 2002 V70 2.5T [1999 V70 2.5 140 - scrapped]

Oct 21st, 2011, 11:56	#4
david philips panic captain manwaring ? Last Online: Jul 2nd, 2018 17:16 Join Date: Aug 2011 Location: craggy island	seems like a fuel fault pull the plug out of the maf and try it , if no better then thats ok. then you will have to look at the spark things like the rottor arm,try a timeing light on and see if the sparks fail when the engine cuts out ,if so it should rule out a fuel fault, then start pulling out one electrical plug at a time check for rot etc put it back and try, sorry i cannot think of any thing else at present. good luck.

Oct 21st, 2011, 13:19	#5
The Hooded Claw Owner Volvovehiclesclub Last Online: Apr 4th, 2014 12:18 Join Date: Dec 2008 Location: Choosing which Volvo to go out in Today !!! lex parsimoniae View Photos By: The Hooded Claw	ALL good suggestions above ..... but from Experience i'd go for the Coolant Temp Sensor meself What you describe is CLASSIC Coolant Temp Sensor Failure Keith __________________ 2000 C70 T5 Phase 1 240 Bhp in Saffron Orange ("SAPPHIRE") 2001 S80 2435cc Now with Andy Northface () 1994 960 CD 3.0 Estate ("The Purple Monster") VOC 25900 lex parsimoniae

Oct 21st, 2011, 10:16	#2
Chris_Rogers VOC Member Last Online: Apr 10th, 2017 16:55 Join Date: Jan 1970 Location: South Kent Coast	Is the coolant temperature gauge behaving normally? Have you checked the vacuum connection to the fuel pressure regulator on the fuel rail? Have you checked the fuel pressure?

Oct 21st, 2011, 20:17	#6
WSparrow New Member Last Online: Mar 20th, 2012 01:21 Join Date: Oct 2011 Location: Vancouver	Thanks for the replies. The fuel pressure and regulator, seem to be good. I've already checked out the maf and it looks brand new. I've only had the car a few months, and not sure what work has been done to it. But I suppose it couldn't hurt to try disconnecting it. The rotor arm and timing are good, when the engine is cold or only partly warm I can get it up to 5000 rpm without it coughing or sputtering and since doing the spark plugs there are no more OBD codes (misfire or otherwise). It hadn't occured to me that the temp sensor might be the problem. The temperature guage is working properly so I never gave it any thought. I'll see if I can get my hands on a working one to test it. Thanks again, I'll let you know how it goes.

Oct 23rd, 2011, 19:05	#7
WSparrow New Member Last Online: Mar 20th, 2012 01:21 Join Date: Oct 2011 Location: Vancouver	Replaced the temp sensor and thermostat. No real change. It idles fine when hot now, but still tries to stall when I give it gas. I've found I can get it to accelerate if I just barely touch the pedal. It gradually picks up, but it at that rate it would take about 5km to get up to speed. I'm at a loss. I'm going to clean the injectors and see what happens when I disconnect the MAF, but might have to bite the bullet and take it to a volvo specialist. Any other ideas before I do?

Oct 23rd, 2011, 19:16	#8
deathrider311271 I've Been Banned Last Online: Jun 21st, 2022 19:26 Join Date: Mar 2010 Location: Grimsby	when was the last time the fuel filter was replaced? it sounds like an air leak somewhere to me, have u checked ALL the turbo pipes? inlet manifold? injector seals?

Oct 23rd, 2011, 20:07	#9
WSparrow New Member Last Online: Mar 20th, 2012 01:21 Join Date: Oct 2011 Location: Vancouver	The fuel filter and fuel pump were replaced last week (after the problem started). I've checked the turbo/vacuum lines as thoroughly as I can but many of them are hard to get at so there could be a pinhole somewhere, I just can't find it. If I hit the throttle while under the hood I can hear a sucking sound while it's trying to stall, but that seems to be coming from the air intake on top of the rad, so I don't think that's it. Also, I did disconnect the MAF and fire it up. It made no difference, it just made the lambda light come on.

Oct 23rd, 2011, 20:22	#10
deathrider311271 I've Been Banned Last Online: Jun 21st, 2022 19:26 Join Date: Mar 2010 Location: Grimsby	spray some carb cleaner around the injectors and see if it tries to stall then, if so your injector seals are knackered. this happened to mine earlier this year As for the MAF you need to disconect it while the engine is running, if nothing happens its broken

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