ss.slp.ls1

Ok lately I've had a stumble at WOT around 5200 rpm. After hooking up a pressure gauge I found very low pressure ~28 psi under load at high rpm.
Before I got the chance to order a new pump the car died at WOT on the freeway. I instantaneously lost all power, which I was hoping was caused by the fuel pump failing. I was able to get the car to limp off the freeway.
I ordered a new pump and installed it last night. Fuel pressure is back to normal, pump primes, holds pressure, etc. Only thing is the car won't start. When I try to start it, it cranks but doesn't turn over. When I stop trying to start it, it sounds like its still, barely, trying to go for a few seconds afterwards.
I don't know why it's not starting. Any help would be greatly appreciated.

ss.slp.ls1

Things I forgot to mention:
Opti - two weeks old
coil - 6 months
plugs and wires - 2 months
fuel pump - new (obvious)

I did the spark test using the icm terminals and got ~11.5v dc from A/D to ground and ~1-2.5v ac from B to ground. I looked at the grounds by the coil, it looked normal. The only thing out of place is a burned wire to the low oil sensor.
Well the battery is low from all the cranking, so I am gonna charge it and do some more troubleshooting after work.

Craddock

Just making sure, you hear the pump priming when you turn the key? I thought my pump died once and it was just a bad connection to the fuel pump relay.

ss.slp.ls1

Yeah, the pump is priming. Right after the install on koeo the pressure shot up to 45 psi and held at ~43, the pump seems to be operating fine.

ss.slp.ls1

I installed a new coil and had the ICM tested and it passed. Also tested the battery. I removed spark plug #1 and it looked normal, not fouled. I had a friend turn the key and I could see the plug sparking (shocked the s*** out of me too). I can turn the engine over by hand, I was trying to see if it was locked. I sprayed some carb cleaner in the throttle body, I was told it would have the same effect of starter fluid, no change. The engine cranks strong, turns over, but doesn't start. Checked all the fuses under the hood, all good.
I don't know what else to test.

ssbowtie1

Hmm odd...so you're getting spark and fuel pressure but its still not turning over.

Have you tried a noid light to make sure the injectors are getting voltage?

hosspwr94

This may seem like a no-brainer but did you check your fuel filter? Just a thought here!
also how many times did you prime the pump before you tried to start it. you could still have air in the line.
When I changed my pump i did the prime/off/prime/off several times before actually trying to start it. and it still had to turn over a few times before it started.

ss.slp.ls1

I have not tried the noid light, I guess that is next on my list. How do you use it?

Yes, I have primed it many times since the pump has been installed. I have a pressure gauge on the schrader valve and it has a bleed off button. I have bleed it and fuel purges out. I even held the bleed button while priming the pump and I had a steady flow of fuel comming out of the bleed hose of the gauge.

I was gonna do I compression test today and see what that tells me.
Can anyone tell me what wires/sensors would stop the car from starting? I wanted to know which ones to check first. Thanks.

Guest47904

Assuming you put enough IGNITABLE carb cleaner in the intake to fire it up, checking the injectors with a noid light is a waste. To be doubly certain the problem is not fuel related, squirt fuel in the intake while cranking it.

Since you did the opti install just 2 weeks ago, I suggest you put #7 at TDC and remove the distributor cap. The rotor should be pointing at the 3 O'Clock position. This will eliminate a broken cam, chain or jumped opti.

Just my .02.

ss.slp.ls1

I sprayed starter fluid in today, no change. Noid light is a waste of time, why? To take the cap off, I still have to remove the waterpump and the harmonic balancer correct?

The car seems to crank strong, but I noticed that the volts on the battery gauge drops below the red when trying to crank the car. It could be that its just getting drained again from trying to crank it so much. I had battery tested yesterday and it was good.

ssbowtie1

I think speedy's point is if you sprayed starter fluid in the tb and it still didn't turn over, then its not fuel related and you shouldn't have to test the injectors. This is probably true, but I like to make sure by directly testing the component, especially when its so easily accessible. I think you can also use a voltmeter. Try a search there should be more info on checking the injector harness.

Do you smell fuel after cranking the car for an extended time? The last thing I can think of it being would be the timing chain. Like speedy mentioned you're going to have to take the cap off and make sure that the rotor is still in sync with the cam and crank.

ss.slp.ls1

Two week old opti...and it failed. I didn't have an E4 torx socket when I had ordered my new opti and I forgot to thread lock them... Needless to say, I found my rotor complete disconnected, both screws had back out. I fixed it and the car fired right up. I'm gonna put the rest of the stuff back on tomorrow; alt, wp, etc. I'll take it for a spin and post the results.

ss.slp.ls1

Well I took the car for a spin, it runs, doesn't seem to pull like I would like it to. Seems to have flat spots, and some slight stumble. I don't know if the opti was damaged when the rotor was loose. I haven't taken pressure readings with the new fuel pump yet, I will. No codes yet so I'll have to wait and see.

hosspwr94

I wouldn't have put that opti back in. I had a similar problem with my msd cap and rotor and an o'reilly's back half that were brand new. I had less than twenty miles on it when it just died on my after taking off from a stop light. I had them replaced under warranty! I have pics of what the screw did to the inside of the cap and I knew that wouldn't be good!
if its a brand new unit I'd warranty it out and get the new one!! with both screwes coming out it probably did some damage to the inside of the cap. On mine I had a couple terminals get bent!

ss.slp.ls1

I think you hit the nail on the head. The car doesn't run well at all. The damage seems to be irreparable. I wonder if I can still warranty it after opening up the cap and putting a drop of thread locker on the screws.