So I'm trying to fix up a 1993 Volvo 850. It wasn't starting and I was doing several things to figure out why. I tested spark and I'm fine in that aspect. I decided next to check to see if fuel was reaching my engine. I heard the hum of my fuel pump and also checked the fuel pressure by sticking something into the valve after I tried cranking it. Fuel shot out of the valve so I'm confident I have fuel pressure. Next I took out the spark plugs to see if fuel was actually reaching the cylinders. However, when my friend started cranking I didn't see any sign of fuel entering any of the pistons. I was told I would be able to see the fuel shooting inside. Is that true? If so, what do you think the problem is, are my fuel injectors bad? If anybody knows any other problems that could be the case PLEASE let me know. This is driving me crazy.

 

there's the fuel injector relay up over the radiator. See if that is being energized. After you crank pull a plug to see if its wet or dry for some clues as well.

 

Wait, there is a fuel injector relay on top of the radiator? I cant seem to find it.

 

the fuel injectors will not be bad. At least not 5 of them at the same time. If you have spark, then see if it'll run on ether. that can be instructive. If you have spark, then the relay on top of the radiator is okay.

They make a "noid light" that you can use to see if the injectors are being commanded to fire. You replace the injector with this light, and so if the injector is commanded to fire it'll flash.

You could get a fuel pressure gauge, if you're interested, and make sure the fuel pressure is correct. that is pretty fundamental to fuel injected cars, and I think it's a tool everybody should have, but a lot of people don't. I have observed that the 850 fuel test port uses the same size valve as a tire, so you can actually measure fuel pressure on the 850 with a tire gauge.

Also, you cannot see fuel entering the cylinders, but you'd smell it. If you crank a little and then quickly remove a plug it should be wet.