My brick doesn't like the sun

"Hiroku" (hiroku) 06/22/2015 at 09:22 • Filed to: None

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Calling all Volvo specialists!

So, basically, my car won’t start if it has sat under the sun for too long. Sometimes it will catch briefly, but then sputter and die immediately after. Sometimes it will just spin endlessly and never even threaten to work. Giving it throttle only seems to make it worse.

If I try to start it early in the morning (before the sun comes out) or after it’s sat in the garage overnight, it fires up immediately (although sometimes it will run a bit crap for the first couple of minutes until it warms up).

Sometimes, after driving for a little while and then stopping for a few minutes (for instance, to get gas) it will not start again. Resetting the ECU and waiting a couple minutes makes it fire right up again though. Perhaps it’s related somehow?

It’s a 94 850 Turbo, in case anyone is wondering.

Any ideas where I should start looking?

mcseanerson > Hiroku 06/22/2015 at 09:29

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I see your problem. It’s fwd.

Alfalfa Romeo > Hiroku 06/22/2015 at 09:30

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Is it throwing any codes?

Without further info, my first guess would be coolant temp sensor. They tend to be somewhat faulty and an improper temp reading would cause your brick to not start.

LongbowMkII > Hiroku 06/22/2015 at 09:31

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take it with a grain of salt, but it sounds like a fuel delivery issue. welcome to be corrected.

Goggles Pizzano > Hiroku 06/22/2015 at 09:36

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MAF failure is more likely to show itself on extreme weather days, since the sensor would normally be providing the most correction to the ETM.

http://blog.fcpeuro.com/2014/05/02/bad…

Hiroku > Alfalfa Romeo 06/22/2015 at 09:37

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That’s a problem. Being a ‘94 it doesn’t have OBD-II, just the crappy little flashing-lights-thingy. The A2 socket (Fuel System) doesn’t have any codes except 3-2-5 (ECU memory failure), which I suppose is because I took off the battery recently. A6 socket (Ignition System) simply doesn’t work at all (doesn’t even throw 1-1-1 which is supposed to mean “No errors found”). So I guess we’re on our own.

I thought about the coolant sensor as well. Might need to check that out.

Googling similar issues seems to point towards the Fuel Pump Relay (I can definitely hear the pump priming, so don’t think it’s that) or something to do with condensation in the distributor. Does that make sense?

SnapUndersteer, Italian Spiderman > Hiroku 06/22/2015 at 09:38

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bad main relay, or starter relay?

Hiroku > mcseanerson 06/22/2015 at 09:39

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But fighting the ridiculous amounts of wheel slip and torque steer when the turbo kicks in is so much fun!!

Hiroku > Goggles Pizzano 06/22/2015 at 09:40

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Any quick way I can test the MAF? I tried cleaning it and then unplugging it to see if it made any difference, but nothing changed on both counts.

Hiroku > SnapUndersteer, Italian Spiderman 06/22/2015 at 09:42

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I can definitely hear the fuel pump priming, so I’ve ruled out the main relay. I could try bypassing it temporarily with the paper clip trick and see if it makes any difference, but I doubt it.

It always cranks normally, so I’m guessing it’s not related to the starter.

mcseanerson > Hiroku 06/22/2015 at 09:42

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Yeah but the old school turbo bricks won’t let a pesky thing like the sun stop them, not even if they’re driving on the surface of it.

Goggles Pizzano > Hiroku 06/22/2015 at 09:42

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After reading your comment, I agree. Fuel pump relay may be the culprit. I’ve had a bad one and there was no audible problem. It gets hot enough to just cause it to stall.

Alfalfa Romeo > Hiroku 06/22/2015 at 09:43

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Oh right, haha. I feel dumb about the obd thing now.

It could just as easily be a fuel delivery related issue, but I have known of a few coolant temp sensor/thermostats to go out. It’s just the slightly more common 850 issue that’s worth looking into. One more question, does the fan ever run after you’ve shut off the engine?

Goggles Pizzano > Hiroku 06/22/2015 at 09:45

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Seeing how you’ve checked your codes, you would have seen one. Probably not it.

Hiroku > LongbowMkII 06/22/2015 at 09:48

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Time to invest in a fuel pressure test kit...

Hiroku > mcseanerson 06/22/2015 at 09:49

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Can’t argue against that.

Which wheels deliver the power to the ground seems to have little influence on that, though!

V8Demon - Prefers Autos for drag racing. Fite me! > Goggles Pizzano 06/22/2015 at 09:49

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If the memory in the ECM was wiped due to a battery disconnect, or it’s borked altogether, he won’t see a code. The lack of codes on the A6 he described points to the latter.....

Hiroku > Goggles Pizzano 06/22/2015 at 09:52

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I will definitely try the paper-clip trick to rule out the relay, then! Will let you know if it works.

DrScientist > Hiroku 06/22/2015 at 09:54

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vampire volvo.

wooden stake right to the middle cylinder.

Hiroku > Alfalfa Romeo 06/22/2015 at 10:01

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Not sure about the fan, I think I can recall it running for a few seconds after I turn off the key but I’d have to double check that. Why?

Alfalfa Romeo > Hiroku 06/22/2015 at 10:07

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If it’s a sensor telling the engine it’s too hot, it will keep running by the fan after shut-off to cool itself more. Otherwise the fan should shut off with the engine.

JGrabowMSt > Hiroku 06/22/2015 at 10:22

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I wouldnt necessarily call myself a specialist, but Ive seen a couple movies about this.

I believe the proper tools are garlic, wooden stakes and possibly a silver bullet or two. I think given the circumstances, some Holy Water could be substituted for some sugar in the gas tank, but don’t quote me on it.

m-b-w loves his SUBAROO > Hiroku 06/22/2015 at 12:10

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I used to have a 94 Volvo 850 turbo, and it had an OBD port and the crapy lights thing. Here’s a Pic of where you might have an OBD port.

Hiroku > m-b-w loves his SUBAROO 06/22/2015 at 12:30

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I can say with 100% certainty that my car does not have OBD-II (sadly). I have checked.

m-b-w loves his SUBAROO > Hiroku 06/22/2015 at 12:33

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Mine must have been a late production 94, as it wasn't supposed to have one but it did.

roflcopter > Hiroku 06/22/2015 at 13:02

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If you can unplug your MAF and the engine doesn’t change at all then there is something bad going on with it. It should cause a quite noticeable change in idle when it is unplugged.

wacopalypsenow > Hiroku 06/22/2015 at 13:10

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CPS (crankshaft position sensor) tends to cause this sort of problem when they are bad. When they start going out heat will cause them to malfunction, and you have to wait for the car to cool down to restart. Here is a thread that you might wanna check out.

http://volvoforums.com/forum/volvo-85…

RallyWrench > Hiroku 06/22/2015 at 13:12

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The ECT can do this, as can the MAF, but given that it only happens warm and after sitting in the sun, I’m leaning towards a sticking (open) Evap purge valve, located on the core support on the driver’s side of the engine compartment. The valve defaults open and is only closed on command from the ECU, and when they stick open, they cause an excessively rich mixture due to fuel vapor from the charcoal canister entering the intake manifold at the wrong time. Because the fuel tank pressure increases as the car sits in the sun, it vents more to the charcoal canister, which then vents through the open valve to the intake. This would also explain the poor running for a bit once started. The car is old and “dumb” enough that this can happen without codes, since the valve defaults open when off. It runs fine after sitting overnight because it needs a rich mixture at that time. If you take the purge valve off, you can apply 12V & ground to it, and if you can blow through it when powered, it’s bad.

The other possibility is a bad non-return valve in the fuel pump failing to hold pressure in the rail, but this shouldn’t really be affected by sitting in the sun. If you have access to a fuel pressure gauge, this is super easy to test with the fitting on the rail. It should something more than 20psi in the system when off.

Hiroku > RallyWrench 06/22/2015 at 14:31

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I was hoping someone would mention the EVAP, as it was my was my first suspect as well. Would explain everything, wouldn’t it?

Sadly I’ve ruled that out already by disconnecting the valve-to-manifold hose for a couple of days, thus bypassing the whole EVAP system and venting the tank vapors straight to the atmosphere (sorry polar bears). Made no difference when I went to start the car again later, so wasn’t it.

As for the fuel pressure, I don’t have a gauge, no. Should probably invest in one, though. Definitely a handy thing to have lying around for times like this.

Hiroku > roflcopter 06/22/2015 at 14:34

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I will test that tomorrow if I have the time, along with the coolant temperature sensor, and get back to you guys. Thanks for the help!

Hiroku > wacopalypsenow 06/22/2015 at 14:38

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Will add that to my list of things to check. Wouldn’t that cause issues with the engine running when warm, though? My problem seems to be only with starting.

Hiroku > JGrabowMSt 06/22/2015 at 14:40

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Nice suggestion with the stake , garlic etc., but I’m not exactly hoping to KILL IT here. Quite the opposite, in fact!

Hiroku > V8Demon - Prefers Autos for drag racing. Fite me! 06/22/2015 at 14:48

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The thing is, I took off the connector to the diagnostic module to try and figure out why A6 port isn’t throwing any codes and, to my surprise, the little terminal which goes to the ECU (I suppose) isn’t there at all.

I wonder where the hell it went...

Hiroku > RallyWrench 06/22/2015 at 14:57

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BTW, since we’re on the subject of purge valves. You say it defaults open and closes when powered (funny, I thought the opposite made more sense). Does it mean it’s always open when the car is shut off? Or does it keep receiving 12V from the ECU, even if the key is off?

RallyWrench > Hiroku 06/22/2015 at 15:01

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It’s open with the key off. The tank vents to the charcoal canister, and this way the tank can’t overpressurize regardless of conditions when the car sits. So if you just take the valve off the car and blow through it, it’ll pass air.

Hiroku > RallyWrench 06/22/2015 at 15:08

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Ah. I was wondering if that would cause the engine to flood with vapors if sat under the sun for long periods of time, but the fumes will only be drawn from the canister into the cylinders once they “see” vacuum from the running engine, right? That makes more sense.

RallyWrench > Hiroku 06/22/2015 at 15:13

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Exactly. This would also explain why it occasionally starts & dies, as the initial injection pulse will start it, but once it pulls the vapors in it’s overly rich & stumbles or dies.

Hiroku > RallyWrench 06/22/2015 at 15:31

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Nice, thanks for the clarification!

JGrabowMSt > Hiroku 06/22/2015 at 16:08

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You’ll just have to live with a vampire wagon then. My condolences.

wacopalypsenow > Hiroku 06/22/2015 at 19:31

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For the most part..yes. The standard CPS issues usually shows themselves after the car is hot and then it begins stalling and won’t start until it cools down. So you have like 50% of the issues occurring....i just re-read the Volvo post I sent you...and if you read the bottom of that Volvo forum link I sent, the same intermittent issues as you and he was working on the crank positioning sensor and noticed the cam positioning sensor was corroded...he fixed it and it solved the problem

twochevrons > Hiroku 06/22/2015 at 21:52

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That sounds almost exactly like the problems that my 850R had when I bought it. Mine wasn’t quite so much temperature-dependent (it showed up equally as much in the height of summer and the depths of winter), but it did seem to be worse with a warm engine. Otherwise, though, it’s the same: intermittent hard starting or failure to start, but no error codes, and it runs just fine.

Have you checked for fuel and spark? There’s a small valve (like a tire valve) on the end of the fuel rail, under the throttle cover. If you depress that with a screwdriver, you should get a spray of fuel, which indicates that the fuel pump is working. For spark, pull out one of the spark plugs, and hold it against a metal part of the engine while someone else tries to start it (being careful to hold it by the rubber plug). It works best in the dark, but you should be able to see a spark jumping across the plug’s electrodes.

In my case, I had fuel pressure, but no spark, and it turned out to be the camshaft position sensor at fault. It’s easy enough to replace – it’s right next to the distributor, on the end of the exhaust cam.

The crankshaft sensor, located just below on the transmission bell housing, is another possibility, but I’d probably try the camshaft sensor first – the engine can probably run fine (but not start) if it loses the signal from the cam sensor, which goes with your symptoms. A loss of signal from the crankshaft sensor will cause the it to lose ignition timing and die, however.

Another possibility might be the immobiliser system. The US market 850s never got it, so I don’t know much about it, and I can’t remember when it started being fitted to the European 850, but from what I understand, if either the key chip, or the transponder ring in the ignition lock, goes bad, you can get those same symptoms, too. Might be worth looking into, but I have no idea how you’d test it.