No Start, Flooding, Etc

[MBT]

As many others in recent weeks my 850 has also experienced some starting issues.

First it just would not do anything and the lights would dim - turned out it was a bad battery (this was a long time coming actually), battery replaced the car started just fine.

Ofcourse nothing is that simple and the next day it would not start. And so the saga began.

In the end it turns out that the engine is getting flooded.

I followed some advise on this board regarding flooding and cranked the engine a few times including some 30+second spans and got the car to sort of start. However it still stalls within seconds and periodically makes a sound I have not heard from it before - the gun fire sound. What's most amazing about this to me is that it is coming from the intake side (I took the hose that connects the throttle body to the air box off and was able to hear it from there) not the exhaust side.

So the Q on my mind now is - what is that? and what can I do about it?

Thanks,

Mike

[MBT]

Anybody?

[64pvolvo1800]

Anybody?

first off, you need three things to make it work: fuel, fire, and timing. IF you're getting fuel and a backfire, then i would be concerned about timing. Check your timing belt for damage, Maybe it's there, (it probably is there), but maybe it skipped a tooth or is missing teeth. The next step i would take is a compression test. If it's backfiring, you may have a damaged valve but the compression will be poor or nonexistant in that hole. Check these things out and report back.

[MBT]

first off, you need three things to make it work: fuel, fire, and timing. IF you're getting fuel and a backfire, then i would be concerned about timing. Check your timing belt for damage, Maybe it's there, (it probably is there), but maybe it skipped a tooth or is missing teeth. The next step i would take is a compression test. If it's backfiring, you may have a damaged valve but the compression will be poor or nonexistant in that hole. Check these things out and report back.

So, I finally got a change to get in there to take a look.

I do not see any damage on the belt, however I did not remove it for a full inspection, so there might still be a tooth missing somewhere.

Before I remove the belt (which is a MAJOR pain in the rear) I'd like to get one thing figured out - how do I adjust timing back to whatever they are supposed to be on both cams? I see a small guide on the intake side that says (30,20,10, 0,10) but nothing on the exhaust side. Nor do I know what those marks should match on the sproket. There are small Ms on the sprokets, which may or may not mean anything.

Anyone got a decent guide for this? Or just some clue as to what I'm supposed to do here?

BTW, Chilton's does not go into any kind of detail on how to do any of this.

Any help would be greatly appreciated.

Mike

[--Aaron--]

Unplug your MAF and attempt to start the car.....I was experiencing VERY similar symptoms and it was a faulty MAF, which did not throw a CEL right away.

[MBT]

Unplug your MAF and attempt to start the car.....I was experiencing VERY similar symptoms and it was a faulty MAF, which did not throw a CEL right away.

I followed your advice and disconnected the MAF (figured that messing with belts would take a lot more time and this would be much simpler).

The car started right away. It behaved a bit odd at first, RPMs jumped up and down around 800 for a few minutes till I connected the MAF again at which point the RPMs stabilized at 800.

I let the car run for a good 20 minutes. Then shut it down and re-started it with the MAF connected.

So... now I'm totally confused what the issue was/is. I'll re-assemble everything and see if it re-starts tonight.

[--Aaron--]

Hmmm....did you have any CEL's prior to unplugging the MAF and attempting to start?

If you now get a constant MAF malfunction circuit low voltage it's probably time to replace your sensor....OEM Volvo MAF only, I just learned the hard way what happens when you buy an OEM "Bosch" unit from secondary companies.