2001 V70XC - no start - what would trip the engine light?

[saq]

Moving to a 2001 from a 86 740 and trying to figure out what would trigger an engine light as it seems there are many more sensors.
Major symptom: cranks but won't start. Occasional "coughs" No engine light. Ran fine the day before when I brought it home.

I figure if I can use the onboard stuff to rule out things as much as possible it might reduce the amount of things to take apart, as it's hard to get at the engine compared to the older models. It looks like fuel pressure may be monitored, and some sort of cam thing as well (did check and yes the timing belt is still on and tight). On the other hand it might disable the diagnostic checks during cranking.

Problem likely fuel or spark, but with the shrouds and distributorless ignition checking is not as simple. Some gas comes out when I press the Schrader valve but I'm not sure how much the spring accumulator is supposed to be holding.

[saq]

Starting to think it is fuel - there is only about a half teaspoon coming out of the Schrader.

[EngineeringBloke]

Do you have Volvo Dice or an ELM unit that could be used with the Torque app? Either of these will let you measure the fuel pressure - it should be between 40 and 60 psi on start (I think). You might also be able to use a fuel pressure gauge and attach it to the Schrader.

The ELM units are on Amazon for under $20 and plug into the diagnostic port near the hood release, and the app (for Android) is free, although I use the $5 pro version.

Might be fuel pump or blocked fuel filter, although it is surprising that it drove normally the day before.

[saq]

Forget about it, irrelevant now. Swapped a bunch of relays around, cranked it more, and now the light is on so will have to start back looking at everything now. Well, except for relays I suppose.

[saq]

No, don't have any of that stuff - coming from 740 and 240 world. Guess I might have to get it (do have a oscilloscope though, but of course that doesn't help at all here).
I'll see if there's a pressure gauge at my dad's place.
Might be able to somehow use a VADIS if I get the DICE thing, though it doesn't seem to be up to the quality of the green books as far as information.

[abscate]

You can check pressure with a cheap tire pressure gauge which you throw away afterwards

You can also use a shot of ether into the manifold to try split the ignition and fuel diagnostic tree

[saq]

OK, so a shot of ether into the pre-air-cleaner intake snorkel got it running and it stayed running even when revved (I shut it off at about 5 mins) (I tried to disassemble the intake after the AMM but got frustrated and figured the air filter would trap the oil).

No cold start injector, so I'm thinking it's gotta be a non-obvious vacuum leak.Only other thing that changed was unplugging/plugging the AMM.
All the things I'm looking at seem to indicate that there isn't a fuel pressure regulator in this system. Is this correct?
Lastly, what is some good service documentation for this thing? The VADIS is not very good, or at least not organized well to where I can find it and in cases has inaccurate information. Haynes doesn't seem to make one, found some Bosch stuff but it's not Volvo specific. What do you use?

[saq]

Well, now it's working just to make things difficult. Who knows for how long though. Guess I'll throw a new fuel filter on it and do a full pressure test.
Anyone know how much of an induction leak the ME7 will tolerate?

[saq]

Can't guarantee it yet, but something was rattling around in the old fuel filter after I removed it, so might have been just an intermittent blockage of the fuel line. We shall see I guess.

[abscate]

If you have a leak in the induction path after the turbo, starting will be hard.

Any other vacuum hose , ME7 is really tolerant

Fuel pressure has to be at 50 psi , ME7 doesn’t like bad fuel presssure.

Intermittent no starts could be a failing fuel pump relay, I think you have the last year of old school fuel relays