Just that this 96 850 N/A is VERY VERY low on power..cant really get up hills and such..
checked everything..no codes..no vacuum leaks..
Starting to suspect the fuel pressure regulator..
and the reason why is that if i disconnect the vacuum line to the FPR it has NO CHANCE in performance...
And WHY are these fpr soo expensive for MY 96 and 97 ..almost twice that of the previous years..

thanks

Matt, the fpr was moved/redesigned for 1996. Check the vacuum fittings back at the fpr for leaks, not just at the front of the intake manifold. You could look at borrowing a guage to check the pressure at the rail, it is a Ford fitting. The pressure increases as rpms go up and should decrease as soon as you let up on the throttle.

I would check the compression on all 5 cyls first, before buying a "suspected" fpr. A junk yard fpr should also work - not a normally failing part.

Klaus
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Volvoless. Sold the R. There is now a void...

Thank you klaus.

but i ONLY see one vacuum line associated with the FPR the one between the intake manifold for cylinder 1=2
Are there more?

Stupid engineers! My 1995 had the fpr on the injector rail with a vacuum line that went to the tree. My 1998 had the fpr by the fuel filter, and what used to be a gasoline return line became the vacuum line which snaked around to the front of the manifold. The 1996-7 are different than the 1995, that is for sure.
When my fpr failed on the 1995, it became very hard to start when cold. Like a crank of 10-12 seconds with a puff of black smoke at startup. It ran just fine otherwise. A normal fpr failure will leave the pressure too high, not low.

Is your gas filter clean? You still need to check compression.

Klaus
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Volvoless. Sold the R. There is now a void...

Tested FUEL pressure.

Its at 43-45 at idle..and does not budge at ANY engine speed..I noticed a slight misfire at which point the pressure drops to about 40..fuel filter is new.

So FPR or fuel pump?..strangely they are about the same price to replace.

What does the compression read? Fuel pressure seems OK.

Klaus
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Volvoless. Sold the R. There is now a void...

Hi Klaus.

Have not done compression yet but shouldnt fuel pressure rise and fall with manifold vacuum? This does not its at a steady 43 and when i rev it up it never changes..

Your FPR is supposed to keep the pressure at 43lbs at all times, even when more fuel is used at engine load. In neutral, there will not be much change in in fuel used as there will be more air introduced to the piston.
Your FPR is not the problem.

Klaus
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Volvoless. Sold the R. There is now a void...

The fuel pressure should be more or less constant but will change if the vacuum line is removed from the regulator or if there is something incorrect about the vacuum.

I posted some time back because my fuel pressure had started to jump around a lot (rapidly, by a few psi). I later determined this was because one cylinder had lost all its compression hence the vacuum in manifold was erratic.

Yep. i've gotten all i need to do a full compression test later today..i'll do bone cold block then a warm engine. and no it would not change the fuel pressure when removing the line from the fpr, and when i shut the car down it IMMEDIATLEY lost all pressure..it would not hold it at all.

will post results later!

That makes the fpr suspect. In my experience on various cars the pressure will hold steady after shutdown for 30 min or more. Alternatively leaking injectors or leaking line somewhere (you would see the fuel). I guess the pump has a check valve of some kind to prevent backflow.

Did a compression check on all cylinder on a very cold block ~30f
210 psi on all cylinder.
I realize that this is VERY high and probably due to carbon build up on top of the pistons.
Now im wondering if im very low on power because this engine has such HIGH compression ratios that its KNOCKING (pre-detonation) all the time?

Did a compression check on all cylinder on a very cold block ~30f
210 psi on all cylinder.
I realize that this is VERY high and probably due to carbon build up on top of the pistons.
Now im wondering if im very low on power because this engine has such HIGH compression ratios that its KNOCKING (pre-detonation) all the time?

That's great! Compression is SUPPOSED to be between 185 and 215 on a NA engine. So that rules out headgasket/valve problems.
It would be nice if you could find a FPR in a junk yard. Also, check the cat when it is cold. Just bang it lightly with the side of your fist to see if things are loose on the inside. It is possible that it is clogging?

I wish I could hear your engine run at load. You could get a can of junk to feed into the vacuum tree to clean out the carbon, if there is any. If you are using regular gasoline, pour some into your snow blower and fill the tank with premium, it's only 20 cents more per gallon.

Klaus
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Volvoless. Sold the R. There is now a void...

Yep I am starting to think clogged cat! and i think that's why i have such high compression numbers..because when the exhaust valves open and the piston comes up not all the air goes out due to the cat causing pressure to build up on the manifold and such so that would account for just about all the symptoms i have. poor power, and such HIGH compression numbers specially on a cold block.

Next step will be disconnecting the cat from the manifold and drive around in my rally car sounding volvo to see if it runs better.

So had some more time to figure things out and it did turn out to be a plugged cat.
On the other side of the pre cat o2 sensor there is a 17mm bung, i removed it and having it run like that the power was restored and there was ALOT of exhaust coming out of that bung.
so new cat is in order.. looks like FCP is the best bet for a factory fit cat any better ideas?

And thanks

Wow. Plugged cats are supposed to be easy to diagnose. I guess we were just looking at the wrong end of the engine.

Nothing wrong with FCP, just make sure it fits a 1996.

Klaus
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Volvoless. Sold the R. There is now a void...