My 850glt runs like crap. (Is throwing a Fuel Bank 1 Rich Code). Which Cylinder is that? I was assuming Bank One is Passengers Side 2,3,4 and 5 being Drivers side,... Is this correct?

Anyway,
I just checked the Fuel Pressure at the rail with the car running, I pressed in on the valve and the fuel hardly had enough pressure to come out into a rag... I would assume there should be enough pressure to shoot a spray to the air box..... am I wrong?

I also pulled the forward line off the Fuel Filter and had a helper turn the key off and on. The flow was not what I expected,... I could put my finger over the outlet and easily hold off the fuel (barely touching it)...

With my finger off the outlet, There was a surge in fuel, but still MAYBE only 2x what was coming out from gravity pulling it . The Fuel Filter is new, BTW. So I doubt If its clogged.

I am getting very suspicious of the fuel pump.
It IS running, I can hear it, but I would expect the fuel to SQUIRT out the Fuel Filter with the Hose off. ????????


Also I pulled the TPS off and checked it on the continuity setting on my multimeter,, (I believe this measures resistance)... I was getting 1144 in on direction and 550 in the other. With it on the Throttle Body I am getting 650 Closed and 1144 WOT.
Is this normal range or is there a problem?
The numbers seem to increase smoothly throughout this range, but I thought I'd ask.
Would be an easy fix.

 

only 2 things im sure of here
1. bank one rich is a generic definition. on a V6 you would have 2 banks (sides) On the volvo there is one bank. so its basically saying the whole thing is rich.

2. I know the manual calls for a "fuel pressure release" procedure when working on most any part of the system. So I too would assume there be more preasure at the fuel filter.

But low fuel pressue and a rich engine seem to be opposite.

 

What he said.

Check the fuel pressure regulator. The vacuum hose leading off of it should never have any sign of fuel in it. If you pull the hose off and can smell gas then the diaphragm inside the regulator has failed and that would allow the engine to pull raw gas right into the engine. If you see any fuel drip from the regulators nipple or the hose or can smell gas when you pull the hose off the regulator is likely the problem or at least a part of it.

Stock pressure is 43.5psi so yes it should come shooting out of there with a lot of pressure. Not so much volume because of the size opening of the schrader valve. But it's still enough to spray you in the face and eyes if you're not careful.
Some cars retain pressure better than others. Retaining pressure is a help for a "next day start up" but the pump should also be able to pressurize or prime the system if you turn the ignition switch to ON for a second or two before turning it to start.
The stock pump should put out up to 80 psi depending on if it's running out an open hose or you have it mostly blocked off. If you took it off the filter it should shoot out of there just like a wide open garden hose (approx 35-50 psi house pressure). From your description, it sounds like something happened in the pump or the pre filter (the sock) might be very plugged.
The sock is the big white filter that goes on the intake of the pump and lays at the bottom of the fuel tank.
FUEL PUMP PERFORMANCE (1)

Application Pressure Volume In 30 Sec.
....................psi (kg/cm)................. Pts. (L)
850 ............. 43.5 (3.06) ................ 1.1 (.52)

(1) - At 12 volts, 68F (20C), with engine off and fuel pump relay by-passed.

The TPS, throttle position switch is just a big "dimmer" like you'd use for a light bulb inside your house.
If your meter is set to resistance, ohms then you want to see a linear progression in your reading as you move the switch through it's range. What you are looking for is the signal to either drop out or spike. As you slowly move the TPS the reading should equally rise or fall all the way from one end to the other. Also make sure the TPS you are working on doesn't need to be adjusted. Ours don't, they just bolt on and that's it. Some do need to be adjusted so you have to make sure you install them according to instructions.

 

Ok. Here's a dumb question, how do you remove the hoses from the top of the fuel pump? I don't think they just pull off... Special tool? I see 2 black hoses and a red wire running into the top of the pump housing. There is another access plate under the platform, I don't see how to get that panel up... ????
(car is 1997 850glt wagon)

I have come to the conclusion the fuel pump is weak or the regulator at the pump is bad. No other way I can think of that would cause such a weak stream at the filter (new filter- by the way).

I haven't yet checked the regulator at the pump. Do I have to drop the tank to get to it?

Also I have noticed when I unplug the Turbo Boost Solenoid, there is absolutely no change in the engines poor performance.
The car still stumbles badly at anything more than about 5% pedal. This condition is under load only, when the car is sitting still, if revs decent... Just a slight hesitation. This could be because the weak fuel pressure, but could the TBS also cause this? What exactly are the symptoms of the TBS not working?

 

Figure out the fuel pressure issue before guessing at any other problems. I remember looking up the resistance values for the TPS and checking mine at some point; I can find it later but at this point you have a bigger issue.

Low fuel pressure like you are describing, is going to make the computer **** a proverbial brick.

 

Like he said. You need fuel pressure and volume before anything else. From what you've described you don't have them now and without them, nothing else is going to help.

Get 43 psi of fuel to the injectors and then we can talk about TPS and BCS function.

Your fuel pressure regulator is near the fuel filter under the car, near the passenger side rear wheel. The part that has the fuel lines coming from the tank and going forward to the engine is separate from the fuel pressure regulator. The vacuum line connects to the fuel pressure regulator.

 

Nope, I have a damper at the fuel rail ( no vac line on it)' one pressure regulator on the passengerside frame below the firewall, (vac line on this one)... And from what they said at advance auto parts, there is another one at the fuel tank.

The car is a 1997 850glt with the turbo.

Any suggestions on removing the fuel pump to test it?

 

Hmmm; pics and engine VIN please? Is there only one fuel line going to rail, or are there two (one's a return line)?

 

Engine is a b5254t vin code has 56 as the 6th/7th numbers.
1997 850glt wagon, silver, automatic trans.

It definitely has a fuel damper at the rail and at least 1 fuel regulator in the line, I was told 2 (another at the tank) by the parts store.

Sorry I don't have any pics of it.

Looks like I'm pulling the fuel pump tomorrow. Anything that I can do to get this one working again, or are they junk when they start getting weak output?

 

i replaced the pump in my wagon just a couple weeks ago.

The fuel lines have a "quick release" connection. On the bottom of the hose there is a part you can push in that will let the hose come off. Im sure there is a special "fork" shaped tool that makes that easy. I was able to use a flat head screwdriver...pry under the hose carefully. If you pry on the quick release part...then the hose will be able to come off. So, pry with the screwdriver and pull on the hose with your hand. dont try to use the screw driver to do both jobs.

The second part you see....that black ring with ridges is what holds the pump in place. My manual said to use a large pliers to twist it off. It is supposed to just unscrew. If yours is like mine (original to the car) it wont be fun. I tried a screw driver on the ridges and hit the screwdriver with a mallet to try and loosen it. This didnt work in my case. I didnt have a pair of vise grips or pliers big enough...and the space there is tight.
My replacement fuel filter came with its own ring. So I used a hammer and a sharp flat head screwdriver to break the ring. Break it at 1 point like a "C" and you will be able to pull it off. Once thats done, the fuel pump can be pulled out.

 

Ok, Luckily the black ring on mine turned easily (by hand actually)?!?! Maybe too easy.
Anyway, I'll post more when I get time to dig into the pump. ...busy the next day or so.
Thanks

 

I corrected my post so as not to confuse anyone else. Early ones, regulator under the fuel rail, late model has it back by the tank.

 

Is that rear regulator t'ed in to the pressure line post filter? What is its purpose (could it just be a check valve)? Does it have a vacuum line?

Just checked mine and I don't see that kit on my 96 Turbo car, just the rail regulator (although I just noticed that there appears to be a test port pre-filter, if so that is handy). Pretty sure the 96 NA doesn't have it either - and its fuel system is also returnless, just one line.

Ronzara says his also has a forward mounted regulator behind the fire wall?

 

I havn't seen the regulator at the tank, I was just told it was there by the computer at advance auto. I asked them to look up price of fuel pressure regulator for 97 Volvo 850glt... He said front one or the one at the tank. I was like, huh ? .. Why would there be 2 regulators?

I also have the check valve in line pre-filter, I pushed it in to see if maybe my filter was clogged or possibly installed backwards, but the weak pressure is present at that check valve as well.

Tomorrow will be the day of truth. I am pulling the pump to check it out.
Is there a recommend way of testing?

I thought about hooking 12 volts to it.. Away from the tank for explosion reasons ... And connecting a battery charger to it to provide 12 volts... Maybe in a 5 gallon bucket of water??
I know the pump is working, but apparently Not well enough. Funny thing is, idling the car, once past the initial stumble, the motor can be accelerated up and hold 4000 rpms just fine. I would think this would cause fuel starvation, but it don't. On the other hand, when the car is in gear, it wont hardly accelerate at all and the engine tries to die, unless to just barely touch the gas pedal... Anything more than about 5% throttle an the engine tries to die. Almost like its loading up, which is unlikely with the low fuel pressure. ??

Just seems odd.
But I do know there is weak fuel pressure throughout the system... All the way from the rear check valve forward... So that leaves the pump or rear pressure regulator ( if there is one) suspect as the cause.

????

 

OK,.. Fixed the fuel pressure problem. Turns out the hose inside the fuel pump came off the topside nipple.
Apparently the pump was changed at some point because the clamps says USA on them,... doubt if thats stock.
SO, with that fixed, car cranks right up, idles and accelerates smoothly through the gears with really strong pickup. I am assuming everything is working correctly

BUT....
I am now getting some different codes... MAF LOW, TURBO SOLENOID LOW, also one about the wastegate and another for Idle control.

The car is running great though.... I am wondering if these maybe residual codes from when I had it all apart and running with things unplugged.

I cleared the codes with my scanner, but they came back upon restart.
?????

 

Pull the battery for 45 minutes to let the computer (hopefully) clear its learned fuel trims.

If that doesn't help, post the code numbers here.

 

10-4 on pulling battery for a while.... Probably let it sit over night.

On to my ABS/TRAC being on...
I pulled the front sensors, out and they were NASTY with grease. I cleaned them up ...all shiny now and reinstalled them... Took the car around the block,.. The lights stayed on.
I have the drivers side rear whelp off now, and can not get the sensor to come off the inside of the hub.
I removed the 10mm bolt. I tried prying ( not to hard) with a flat screwdriver, but that sucker is on there.
any tricks to getting it out without damaging it?

Thanks!!!

RZ

 

Ronzara, since you're already in there is there any way you can take a photo of where the ABS sensor connects to the body wiring ??

 

Sorry, I've got it all buttoned back up already. I think on my car ( wagon) the sensor connector is under the wooden panel that is on the floor behind the rear seats. There is about 4 connections on a plastic plate type thing... I believe a saw a yellow connector on that plate when I disconnected the fuel pump power lead from it.

RZ

 

Interesting thread. May I chime in here with a question? I have replaced just about everything you guys have discussed here already, 740GL '89 Bosch injection system.
Question #1. just realized fuel pressure regulator IS leaking into vacuum, ordered new one and waiting. Would that problem prevent starting & running? (starting fluid makes the engine start for a second)
#2. The throttle position sensor is I think the last item I have not tested. Would that one prevent the engine from running? Seems like I need to have wide open throttle to make the starter fluid trick get a sputter, too.
#3. Is there any way to test the computer itself for trouble, and the last idea is somebody suggested the ignition switch may be bad when going into the run position, so engine dies immediately.

Thanks for any ideas. Just got warm enough here in South Dakota to even get outside to work on this car.