2005 S40 2.4i with manual transmission.

I just changed the head gasket, timing belt, water pump, spark plugs, oil, and coolant.

It cranks fine, I get fuel at the fuel rail but doesn’t seem to be firing... and questioning if it’s even injecting fuel because I would expect to get a gas smell after cranking over for a bit.

I have an OBD ScanTool hooked to a laptop. And have no trouble codes. I’m curious though if a scan tool should read cam or crank sensors.

I have a whining/humming sound that seems to be coming from the throttle body when key is in. If I unplug the plug to it, it stops making noise. Plug it back in and no noise until turning key off and back on.

dumb question but to verify spark, I assume I need to pull the upper intake off, pull coils and plugs and ground the plug, and crank?

I assume if I have a crank or cam position sensor I won’t get fuel injected or get spark.

i have not verified compression after putting back together and will do that to confirm but I’m questioning cam and/or crank sensor due to lack of fuel smell.

Thoughts?

Thanks in advance.

Randy

 

I'd start with the easy checks.

Spray some starter fluid into the intake (take out the air filter). If it fires right up for a few seconds, look for a fuel problem.

Your method should verify spark (you'll need a helper - and might want to do it when it's not direct sunlight, as even a strong spark can be hard to see).

But given that you did all that timing belt / head gasket work, I'd want to take a HARD look at the timing marks, to make sure they are all lined up perfectly (never did a Volvo TB so can't help much there).

And finally, I'm assuming you didn't swap the timing belt because the old one broke or slipped (in which case, you just spent a lot of time and money on a soon-to-be junkyard motor). ;-)

 

See... I knew I asked for a reason. Not sure why I didn’t think about starter fluid. I sure would’ve though lt of it in the horrid days!

No broken belt, it overheated and warped the head. Lost compression on 3 & 4. I can sure go back and double check timing belt alignment but man, I was so paranoid putting it together I am sure I got it right.

Am I right in my thinking about crank and/or cam sensor? If one or other was not good, could lose fuel and/or fire?

Thanks for the reply.

Randy

 

I know that a bad crank sensor can cause you to lose spark, or cause some really bad idle / power problems. A gross electrical problem with the sensor would probably show up on the OBD reader. Don't think it would interrupt the fuel though.

I remember reading about difficulties with getting the Volvo timing marks right without a special tool, but to be honest, I never dug into that one (never had to, happily). I always just assumed "timing marks is timing marks"... but there might be more to it.

 

I purchased and used the cam alignment tool... and again was very paranoid about screwing things up and breaking valves, that I double, triple, QUADRUPLE checked the marks.

I'll hopefully find time to try starting fluid tonight and see what happens.

Thanks for the reply!

Any other thoughts?

Have a GREAT day!

Randy

 

I have a 2005 S40 I have a continuous buzzing sound with the key offer on as soon as I hook up the battery coming from the throttle control module it seems like it's buzzing right where the throttle control module plugs in and plugs out not really sure what it is but it comes from right there anybody got any ideas key on or off as soon as I hook up the battery it buzzes .

 

what you can do is start pulling fuses and/or relays to see what turns off the buzzing, then use a wiring diagram etc to see what's on that circuit. Plan B is to feel around to see if you can feel what's vibrating.