What are the numbers I should see when I do a compression test today. I have a crank but no start after I rebuilt the motor and everything is hooked up right so I am thinking that the timing might be a little off. Is this motor an interference motor? I turned it over and it didnt hit the vales while it was on the engine stand.

 

If all of the timing marks line up and the colors match then you are good; that is what you should pay attention to the most.

"For each cylinder, crank engine through 4 compression strokes.
The lowest reading cylinder should not be less than 70 percent of the highest.
No cylinder reading should be less than 689 kPa (100 psi)."

 

no cylinder should be less then 100 psi, and the lowest cylinder should not be less then 70 percent of the highest cylinder....however, if you lined all the timing marks up on the cam gears and crank gear, you should be alright. Double check all your sensors and wiring......good luck

 

Haha, you beat me too it. I was editing my post and then saw that you had added this .

 

haha yea, it was slow here at the end of the day so I figured I'd hop on SI and look up the #'s haha

 

If you just built the engine, you can tell by the sound of the cranking if the compression is at least good enough for it to start. Really, a compression test is not a troubleshooting step in an engine that won't start. Ignition and fuel are the places you need to be looking. And with this engine, all the electrical connections.

And yes, it is an interference valve train, but you turned it on the stand, so it's fine.

 

Are you getting any check engine lights?

 

All timing marks were right on and the fuel pump starts and I have spark but it just wont fire. I am currently charging the battery. I have all the wire connectors plugged in the right spots and no check engine lights.

 

well if you have spark, the timing is right, and you have fuel (assuming you have adequate pressure at the rail itself), the only thing i can think of would be a lack of compression or the injectors arent firing. to check the injectors your gonna either need a noid light or a fuel pressure gauge and scan tool to do a injector balance test.

 

Yeah, check to make sure you have injector pulse.

 

The car has been sitting for three months. Do you think the fuel could have gone bad? I sprayed starting fluid in the vacuum spot after the throttle body and it still didn't start. Could the crank sensor be stopping it from starting?

 

You probably shouldn't spray that into the blower; it could puddle up in the intake.

You really should check for injector pulse. That starter fluid won't tell you anything.

 

It was just a quick burst to see if it tried to actually start instead of just crank I will check the pulse width tomorrow.

 

When I did a compression test it read 175 for pistons 1,2,4 and 170 for piston 3.

 

Yeah, I see what you're saying.

 

Here's a simple check. Turn on the car's power, and go press open the test port schrader valve on the fuel rail. If you get sprayed in the face, you know at least there is pressure at the rail.

Here's another. How exactly do you know you are getting ignition? Take a spark plug out, ground it, and crank. See if you actually are getting a spark.

 

There is fuel comming out of the rail. I am going to test the exact pressure of it though. And there is spark i have checked that.

 

How about injector pulse? Have you checked that yet?

 

No I am bringing the noid lights home from work today. Will check that as well. Also ordered a fuel filter because I have twenty thousand miles on the car. Figured it might be a cheap solution.

 

Well let us know what you find out when you use the noid lights.

 

I will no in three hours. What do you suppose could be going on if the noid lights dont flash at all?

Edit:

No blown fuses or bad relays either.

 

Check with a scan tool to confirm you see "Engine Speed/RPM" while cranking
How exactly did you have the timing chain and gear marks oriented?
Did you install the camshaft position sensor (CMP) at that time as well? (while everything oriented to COMP TDC#4)
Wop

 

I just pulled the head off didnt pull any of it apart, I lined up all the color marks where they were suppose to go according to the build book. Like I said I have a interceptor. What should I be expecting to see as far as rpm and pulse width?

 

First you just need to see if the gauge registers any rpm or injector pulse at all. Don't worry about exact numbers until you confirm this.

Just check out the rpm while cranking, and check for power at the injectors as well as pulse.

 

So I checked with the noid lights and it is showing voltage at it and the gauge shows 19rpms while cranking. The pulse width is showing 3.4. I am starting to think the car is never going to start.