New Motor Wont Start

[VTEC_THIS]

I just put a new motor into the car, it's primed and ready to go but it wont start. I've been following this article to try to diagnose why the engine's not starting.

http://www.dsmtuners.com/forums/articles-miscellaneous/217951-how-diagnose-no-start.html

Fuel
I'm definitely getting fuel, I pulled the spark plugs and they have gas on them.

Spark
I checked spark down to the plugs, so I know I'm getting spark.

Compression
I did a compression test and this was the result:
Cylinder 1: 50 PSI
Cylinder 2: 47 PSI
Cylinder 3: 25 PSI
Cylinder 4: 70 PSI

Compression is obviously low, but keep in mind that the engine isn't warmed up, and the piston rings aren't seated yet.

Timing
I double checked timing and it's dead on.

Other Things I've Checked
-Firing Order is 3214 (1g coil pack)
-CAS is timed correctly
-CAS wiring harness is correct
-Coolant Temp Sensor is working (reading 65*F today through DSMLink)
-Settings in DSMLink - injectors are dialed in, invert cas option is enabled, adjusted tps for my q45 tb.
-ECU - pulled out ECU, looked fine...no bad smells, no leaky caps, or damage (plus no other indication that ecu is not working)


My car is a 97, and I swapped in a 1G 7bolt. I bought the block and head from someone on DSMSource. The block is built (freshly rebuilt from a machine shop) with wiseco pistons, eagle rods, and a new oem crank. The head is 1G, I was told it was recently rebuilt and decked, and has low miles on it. Balance shafts are removed. I'm using ARP head studs and mls headgasket.

Only things I can think of is possibly bent valves because of the compression test. But like I said beore, I'm not sure how reliable the results are since the engine has never been started, and the car's sitting cold.

Also, the car's been sitting since October. Could the gas be bad?

Might pick up more spark plugs tomorrow, in case all the cranking could have fouled the plugs.

 

[1992awdlaser]

The compression is keeping the car from running. I had 85 as the highest number in two cylinders and 60 something in the other two and it wouldn't start. I did a leak down test and found out the valves were leaking. Put a different head on and it started and compression was back up. Do a leak down test.

1.Take the valve cover off
2.Rotate engine until cam lobes of cylinder #1 are pointing up.
3.Put air into the cylinder.
4.Listen to the intake manifold and the exhaust. If you hear air in either your valves are leaking.
5.Repeat on the other cylinders.

Most compression testers have a hose that can hook up to an air hose.

 

[VTEC_THIS]

The compression is keeping the car from running. I had 85 as the highest number in two cylinders and 60 something in the other two and it wouldn't start. I did a leak down test and found out the valves were leaking. Put a different head on and it started and compression was back up. Do a leak down test.

1.Take the valve cover off
2.Rotate engine until cam lobes of cylinder #1 are pointing up.
3.Put air into the cylinder.
4.Listen to the intake manifold and the exhaust. If you hear air in either your valves are leaking.
5.Repeat on the other cylinders.

Most compression testers have a hose that can hook up to an air hose.

+1 For the leakdown test and how to. I'll post back tomorrow with results. I have to pick up a new jack.

 

[VTEC_THIS]

I went back out the garage, and I was able to do the leakdown test on cylinder 3 (which had the lowest compression at 25psi). I did the leakdown test at 40psi, and I didn't hear it leaking out of the intake or exhaust manifolds. Is 40psi enough pressure to check if the valves are leaking, or should I use more air pressure?

 

[1992awdlaser]

Check to see if it is leaking out of the exhaust itself. Just put air in the cylinder and walk to the back of the car. You won't hear it from the exhaust manifold unless there is a crack in it. This might not work to good though. If it is leaking out of the valves it will probably leak out before you get to the back of the car. So you might want to have somebody else put the air in while you are listening to the exhaust. I had to have somebody else put the air in for me due to this reason.

 

[VTEC_THIS]

Thanks again. I'll let you know the results in a minute.

 

[silver bullit]

Fuel
Are you sure all injectors are in working order, not leaking, dribbling, not spray 100% spray pattern and not intermittently working or clogged?

Spark
Check each plug wire, spark plug and coil pack and is getting a steady spark while motor is cranking.

Compression
Even when my motor was cool not ran for 12 hours and 85 degrees i still was getting 120 plus.

Sounds to me you got some bent valves. The lowest i could ever get a motor to sart on was 50-70 psi in each cylinder with a few cap fulls of oil in each.

Anything with 25 psi is not good.


You sure the fuel pump is working and not clogged.
How much gas in the tank?


Are you sure you are doing the comp test right?
Throttle is wot while cranking and radiator cap is off?



Anyway you put it 25 psi is gonna be a no start.

Redo the comp test as i stated above how to do it.

 

[1992awdlaser]

Are you sure you are doing the comp test right?
Throttle is wot while cranking and radiator cap is off?



Anyway you put it 25 psi is gonna be a no start.

Redo the comp test as i stated above how to do it.

If you do this, watch the coolant while somebody else cranks it. If you see a lot of bubbles then your compression is leaking into the cooling system most likely due to the head gasket.

 

[VTEC_THIS]

Thanks for the quick responses, I listened to the exhaust and it was leaking. Damn what luck, rebuild to a rebuild.

 

[1992awdlaser]

Thanks for the quick responses, I listened to the exhaust and it was leaking. Damn what luck, rebuild to a rebuild.

That sucks. Let me know if you have any more questions that I might be able to help with.

 

[silver bullit]

Thanks for the quick responses, I listened to the exhaust and it was leaking. Damn what luck, rebuild to a rebuild.

One thing you have to check is while you are doing this is to make sure that the tb is open and the cylinder you are pumping air into has both the intake and exhaust valves closed.

 

[VTEC_THIS]

Well, we just went out and picked up a 1g head for $200. It's supposed to only have 500 miles on it.

All I can say is...damn, I'm pretty bummed out about the car. All this work, then to find out I have to go back and replace the head. Doing the timing belt was tough enough when it was outside the car, I'm not looking forward to doing it while it's in the car. I'm considering hiring a local experienced dsmer to do it for me. If anyone's interested in helping out, shoot me a pm. I might post a new thread for help in regional or something. I'm kind of losing patience with the car.