Hello, I have owned my 1994 850 Turbo for about 6 months and really dig it. Now I am having a strange issue. Here is the deal.
Power steering hard line on the rack sprung a leak from rubbing on a heat shield. That was a Pain. I removed the line and had the hole silver soldered closed. At that point my pump had burned out so I replaced that. Not sure why Volvo had to use so many bolts to hold it on, but whatever. During that job I removed the two ecu blades in the cooled box on passenger side of engine compartment. After that it ran great for a couple days. Then all of a sudden one night it started fine but would not accelerate normally, had no power and rpm drop when throttle was over 15%. Now it's hard to start, won't stay running. I have done the following:
checked and cleaned the plugs
wires seem fine
can't find a vacuum leak anywhere
air filter is clean
trans fluid fine
fresh oil/filter change
Changed the fuel filter and it seemed to run better after that but only for a little bit.
The fuel relay seems to be working, clicks with key on
the pump is pumping fuel with key on.
Here's the deal, I disconnected the line after the filter to check the pump and the fuel coming out(after the new filter) has quite a bit of black sediment in it. I am thinking my fuel tank is dirty or contaminated and now by injectors could be dirty/clogged. Not sure how the dirt or whatever is getting by the new filter but it is. I'm thinking my next step is pulling the pump and checking that filter, then maybe some how draining and cleaning the tank and some how cleaning the injectors.
Any thoughts or advice would be appreciated, I miss driving it.
Cheers,
Sterling

 

Pump some of that fuel into a glass jar and let it sit. Does the stuff settle out ?? It shouldn't as if it's big enough to settle out the filter should have caught it.

If it's in suspension something is mixed in with your fuel and your whole fuel system might be compromised.

What brand filter did you use ??

 

It did settle in the bottom of the jar. I strained it through a coffee filter and a lot of it went through that so it's pretty fine, powder like. The filter was a WIX from O'reilly's, the only one they had in stock.


Now it will start but die immediately, whether I give it gas or not. I'm going to check the pressure on the rail and go from there.

 

Wix is a good filter so it's not the problem.
This stuff must be small and it's in the gas. Sounds like you'll have to pull the tank and flush, replace the sock on the fuel pump, flush the pump, replace the new filter with another filter (Wix or whatever), flush the line to the rail and the rail and if necessary have the injectors cleaned or replaced Except for the injectors it's stuff you can do yourself and I'd do all that first and see if it runs before you do anything with the injectors.

Do you have a locking gas cap ?? Made anyone mad lately ??

 

Yeah, that's what I've been thinking. I had a crazy roommate move out the same time this problem started out of the blue, car ran perfect for that. Is there an easy way to drain the tank?

 

Time for a locking cap.
Easiest way would likely be to take the fuel filter out and use a drain pan to catch fuel as you use a paper clip to jump the pump. Hadn't run one of my Lincolns in over a year and ended up using a gallon jug under the hood at the fuel line disconnect with a paperclip to drain the tank and get some fresh stuff in there. Luckily I have an 88 chev PU with a FI 350 I put the gas in. It was noticeably doggy. I also dump my one gallon of 2 cycle fuel in there every 6 months and make fresh if I haven't used it up by then.

You'll need to have someplace to dump as it can't go into an oil recovery tank like autozone, oreilly ... too much gas and it would be an explosion hazard as their tanks are inside. You can't put it in another vehicle as it's likely the cause of your problem so hopefully you have a county hazardous waste site. They can usually take severely diluted oil or bad gas.

Or find a Safety-kleen location or something like it.

 

You can drain about 8 oz of gas out of the fuel rail to see what gas looks like there. When I drained a tank, I disconnected the fuel line at the filter, into a pan. Just cycled the key and it filled up pretty quick.

If you don't have good pressure at the rail, try jumping the relay to make sure the pump is not cutting off.

 

Ok, so I put a gauge on the valve on the fuel rail and I am only getting 10 psi max. This leads me to believe the fuel pump is under performing or maybe an issue with the regulator. The fuel pump looks like the original Volvo, car has 230k miles. I pulled the vacuum line off of the regulator and it was dry. If the regulator had an issue would it limit fuel pressure?

 

If you have good battery voltage (12 volts) to the pump then either the pump is shot, the fuel filter is restricted by that crap. Have you flushed the system and did you install a new filter yet ??
The regulator could be gummed up and is allowing fuel to run back to the tank and not build up pressure. The diaphram could be good and still be damaged from that stuff you found. Could be jamming it open internally.

Need to pull the filter and try to check pressure there to see if the pump is pushing.

 

new filter, gas is coming out of it clean now. How can you hook up a gauge to the fitting that goes to the filter? I put my finger over the exit side of the filter and it stopped the flow no problem. Doesn't feel anywhere close to 40 psi, probably more like 10 psi. Also is there a way to check if the regulator is working before I spend money on a fuel pump?

 

You need a gauge that has a hose with an open end to it. The newer gauges come with a schrader valve attachment as most have standardized to that fitting. The older gauges used to have adapters, lots of adapters to "T" them into the line or straight clamp them to the line on various types of systems and various sizes of fuel line.

Some auto parts stores have it as a loaner kit.
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If you could block the flow with your finger the pumps shot or the rubber line inside the tank from the pump to the top of the pumps hanger is ruptured. With no regulator in the system and the line capped you should see close to or a little over 80psi depending on the pump. In any case way over the operating 45 ? psi and more than enough to push your finger out of the way and spray you