Just got done with my biggest job to date - had a valve burn, so I had a head machined and rebuilt, then installed it.

As you will know, I had to take a lot apart to get to everything.

After putting it all back together, the car cranks, but won't start. I pulled a plug, grounded it on the head, and it doesn't spark.

Any ideas where to start? I spent all weekend on the job, and it was getting dark when I got it all together, so instead of celebrating my victory with a quick drive around town, I had to accept defeat, and put all my tools away.

Thanks, as always!

 

Did you check the RPM sensor and camshaft position sensor? Sounds like there may be a connector that's loose... Also give it the ol' shifter row in case your PNP is acting up. Final thought is it could be the immobilizer - not sure how to reset that on the 97s - try locking/unlocking the doors 5 times with the key fob... that works on other models.

 

How does the immobilizer immobilize the car? Does it stop the engine from cranking completely? Stop spark? I guess that's worth a look. One problem, I don't have a working fob.

 

I like this for starters:
https://www.volvoclub.org.uk/tech/se...ting-Turbo.pdf




There is a cam sensor test in this one that works great:
https://www.volvoclub.org.uk/tech/se...sicTesting.pdf


These are for 95s but still useful.


You can also trigger the cam sensor with a metal object and it turns the output signal on and off. There shouldn't ever be a reason to be confused about whether it's good or not. The crank sensor is not as easy to be sure of.


I suppose it ought to set an OBDII code while cranking if one of the sensors is working and the other isn't.

 

I believe the code won't set until the engine starts.

 

It might need a certain RPM for it to set some fault codes and cranking might not reach that point.

Do you notice the smell of gas when you're cranking ?? Wondering if the injectors are firing. If they are or aren't it just narrows down where a problem might be.

You've checked all the fuses and especially the connections at the battery and under the fuse box ??

 

I can't say that I smell gas. But I'm not sure how I tell if the injectors are firing?

I hear the fuel pump prime when I turn the key to accessory.

I checked the fuses that looked relevant based on the owners manual and legend in the lid of the fuse box. I can check the others. I have not looked under the fuse box though.

One thing to add that may or may not help - the up arrow in the dash cluster flashes as soon as I turn the key to accessory. Someone told me I might have a bad PNP switch - but it was fine when I parked the car before I pulled the head? I went over the PNP connector, and it's connected etc.

 

My Saturday morning plans are to head to the JY, get a cam sensor, crank sensor and PNP switch......

 

Even though it makes me look like a dumb*ss, I'm going to post the resolution here, in case some other dumb*ss has the same problem in the future

It *is* possible to reverse the connectors between the exhaust cam position sensor and the vacuum tree on the side of the airbox.

Yes, one wire will seem too short, but if you're tired after working 12 hours in 90+ degree heat, you can convince yourself it seemed tight when you unhooked everything.

Now, to finish digging through a few other little issues that popped up in this process!