IPD - Volvo Parts SpecialistsVolvo PartsVolvo Salvage: Used Volvo Parts and Over 50 Years ExperienceSouthern Vo Vo sells genuine used Volvo parts

Please use this Amazon link ... and help keep MVS on the Web. Thank you!Amazon.com

Advertise here via Google

Login

Not part of the forums? Register. It's free.

Need help? See our Help Page.

Trouble shooting a bad fuel pump

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.
1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

Trouble shooting a bad fuel pump

Postby sleeper850 » 09 Apr 2010, 03:40

1998 V70 AWD Turbo 158,000 miles
I recently ran the car out of gas. The car stalled of course and I attempted to restart the vehicle several times to try to move it off to the side of the road. I refueled with 1/4 tank and eventually got the car started. The idle was rough and the car hesitated and stalled while driving. I started the car and let it run but it would stall at idle several times. The car was driveable but not normal. I replaced the fuel filter and the car has the same symptoms. The code reader says MAF or VAF. When I start the car and rev the engine the rpms drop and then resume. It does this every time I press the gas pedal. The exhaust consistently smells like sulfur and when the car reaches normal temperature the car stalls more frequently. I would like to avoid chasing possible problems and buying unnecessary parts. I would appreciate some advice on troubleshooting this. Also, is the fuel pump located on the passengers side floor board in this vehicle. If so, I will follow the fuel pump repair posted here. Thank you for your time and advice.
sleeper850
Forum Member
Forum Member
 
Posts: 28
Joined: 16 Nov 2006, 04:25
Location: kansas city, missouri

Re: Trouble shooting a bad fuel pump

Postby Ozark Lee » 09 Apr 2010, 04:10

Thank you for a very complete post on what actually led up to your issue. It is usually about page three where it is revealed that the gas tank was run dry or that the spark plug wires were melted to the head after the car ran out of coolant.

The bummer about many fuel pump issues is that fuel pressure is not a monitored system hence it will post no codes on its own. Low fuel pressure or low fuel flow will, on the other hand, post other codes such as fuel trim limit errors or MAF errors.

What you need to do is check the fuel pressure both at idle and under load. You can buy a fuel pressure gauge for cheap at either Harbor Freight of even O'Reilly Auto Parts for around $35.00.

I am normally in Fairway and I have a gauge in the tool chest in the garage but I am out of town on a job at the moment, were I at home I would loan it to you or help you check it out.

What were your specific P codes?

My only Volvos at present are 850s and yanking the fuel pump and checking the filter sock is a snap. On the XC's things are way different and you either need to drop the tank or cut a hole in the floorboard behind the rear seat to get to it. I don't have VADIS on my laptop so I can't tell what you need to do on a V70 AWD.

Inasmuch as you ran it out of gas immediately prior to the problems I think you are on the right path.

...Lee
'94 850 N/A
'96 850 N/A
'96 Platinum Edition Turbo
'98 S70 T5
'99 V70XC - RIP Killed by a drunk driver.
Previous: 1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe
User avatar
Ozark Lee
MVS Moderator
MVS Moderator
 
Posts: 11923
Joined: 07 Sep 2006, 14:24
Location: USA Midwest

Re: Trouble shooting a bad fuel pump

Postby jblackburn » 09 Apr 2010, 04:36

The procedure, unfortunately, for your car is the same as one of the XC's. You'll have to cut a hole in the floorboard, or drop the rear suspension out and drop the tank. I'd start by checking the fuel pressure and see where that leads you. If you see problems there, I or someone else can direct you to the write-up someone did about replacing one on an AWD model.

The exhaust consistently smells like sulfur and when the car reaches normal temperature the car stalls more frequently.

This, to me, however, sounds like an air issue rather than fuel. It's way overcompensating for something, either an airhose is loose, or the MAF is dead. I did the exact same thing to my car last weekend when I neglected to clamp down hoses all the way, and it happened when my airflow sensor died before that. Can it run any better with the sensor unplugged entirely?
'98 S70 T5 218K miles
2012 Chevy Cruze LT 6MT


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!
User avatar
jblackburn
MVS Moderator
MVS Moderator
 
Posts: 13631
Joined: 08 Jun 2008, 21:54
Location: Alexandria, VA
Model and Year: 1998 S70 T5

Re: Trouble shooting a bad fuel pump

Postby sleeper850 » 09 Apr 2010, 04:43

After reading the post for the faulty coolant temperature sensor, these symptoms sound similar to the bad fuel pump. Now, I am looking at the faulty coolant temperature sensor as a possible culprit. I will gladly take your advice and check the fuel pressure first and go from there.
sleeper850
Forum Member
Forum Member
 
Posts: 28
Joined: 16 Nov 2006, 04:25
Location: kansas city, missouri

Re: Trouble shooting a bad fuel pump

Postby sleeper850 » 09 Apr 2010, 04:48

I have "cleaned" the MAF and do not notice any difference. I have also disconnected the MAF and and started the car and did not notice any change in the idle. I have not attempted to drive the vehicle with these changes bc I don't want to get stranded again.
sleeper850
Forum Member
Forum Member
 
Posts: 28
Joined: 16 Nov 2006, 04:25
Location: kansas city, missouri

Re: Trouble shooting a bad fuel pump

Postby jblackburn » 09 Apr 2010, 05:02

OK, possibly one thing eliminated then. One other thing to add to your list of checks would be the fuel pressure regulator just under the silver fuel rail cover. If you can take the cover off and pull off the vacuum line to the regulator (look away while you're doing this, don't ask how I know), gas shouldn't spurt out or the vacuum line is wet. A bad regulator can dump fuel into the vacuum system and cause rich-running conditions and hard starting.
'98 S70 T5 218K miles
2012 Chevy Cruze LT 6MT


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!
User avatar
jblackburn
MVS Moderator
MVS Moderator
 
Posts: 13631
Joined: 08 Jun 2008, 21:54
Location: Alexandria, VA
Model and Year: 1998 S70 T5

Re: Trouble shooting a bad fuel pump

Postby sleeper850 » 09 Apr 2010, 05:08

Is the fuel pressure regulator located at the end of the rail? Is it capped?
sleeper850
Forum Member
Forum Member
 
Posts: 28
Joined: 16 Nov 2006, 04:25
Location: kansas city, missouri

Re: Trouble shooting a bad fuel pump

Postby jblackburn » 09 Apr 2010, 05:14

Nah, it's a silver frisbee-shaped thing sort of towards the passenger side of the car on the fuel rail. Take a look at the PDF misha posted in this thread:

viewtopic.php?f=1&t=25331
'98 S70 T5 218K miles
2012 Chevy Cruze LT 6MT


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!
User avatar
jblackburn
MVS Moderator
MVS Moderator
 
Posts: 13631
Joined: 08 Jun 2008, 21:54
Location: Alexandria, VA
Model and Year: 1998 S70 T5

Re: Trouble shooting a bad fuel pump

Postby sleeper850 » 23 May 2010, 01:03

I replaced the fuel pump (using the cut the whole in the floor method) and the car ran better but the sulfur smell was still present. I then replaced the MAF with a Bosch replacement but the smell was still there. I decided to replace the coolant temp. sensor and the sulfur smell disappeared. Thanks for your help.
sleeper850
Forum Member
Forum Member
 
Posts: 28
Joined: 16 Nov 2006, 04:25
Location: kansas city, missouri

Re: Trouble shooting a bad fuel pump

Postby whoa » 23 May 2010, 01:49

Wow; bad luck to have the ETC sensor go out just when you ran empty.
1996 850 Turbo Wagon
whoa
Forum Member
Forum Member
 
Posts: 455
Joined: 30 Jul 2008, 17:00
Location: san francisco
Model and Year: 850 Turbo Wagon 1996

Re: Trouble shooting a bad fuel pump

Postby cn90 » 23 May 2010, 03:02

Fuel Pump is normally cooled by gasoline. So running out of gas is a sure way to kill a fuel pump.

At 160K miles, If I were you, I'd get a new Bosch Fuel Pump for $150-200 or so.

Not worth the headache, safety issues fixing a fuel pump that is on the way out anyway.

Do not ever run any fuel tank below 1/4, you are asking for expensive repair.
1998 S70 GLT 160K+
2005 XC90 2.5T 85K+
User avatar
cn90
Senior Forum Member
Senior Forum Member
 
Posts: 3415
Joined: 31 Mar 2010, 15:54
Location: Omaha NE
Model and Year: 1998 S70 GLT


Return to Volvo 850, S70, V70, C70 & V70-XC Forum (1992-2000)

Who is online

Users browsing this forum: Acknar, Bing [Bot], chrafael, eric4ch, Google [Bot], JRL, kahl, kevjandon, levi_850, volvo_mania and 153 guests