No, the low oil level sensor is strickly an "idiot light" device that has nothing to do with the running of the engine.

As a rule GM does NOT shut their engines off based on oil level, oil pressure, etc.

 

so I got my autotap software installed and setup and gave it a run. Unfortunately it didn't tell me anything. There are no codes in the computer being tripped, and there isn't anything else that seems out of place. The only possible thing that looks a little weird is that it says this...

Throttle Position Angle: 16.1%

If I move the accelerator pedal, it does go all the way up to 99%. Is this supposed to say 0% and 100%?

I'm going to get a fuel pressure gauge right now, and if I feel like staying in the cold, I'll pull the intake manifold. Is there any trick to doing that?

Looks pretty straight forward.

Oh, and I haven't been able to test teh throttle body yet. I'm trying to figure out how to step on the pedal and be in front of the engine at the same time Maybe I'll have to set up my video camera to watch for me... ha ha.

Mike

 

I did a printscreen of the OBDII reader program if anyone wants to check it out and doublecheck that everything looks good.

Thanks!

 

oh, one more thing I thought to try. I turn the key and it starts pretty immediately, revs up for about a second, then dies. I wanted to see what would happen if I never stopped turning the key to the crank position.

It died, then I kept cranking it for about 5 seconds and it never tries to restart. Which to me means that the computer is not giving it spark and fuel. Maybe I'm wrong. I'm going to get that presure gauge now.

 

okay, so I got the fuel pressure gauge and it says 55 psi pretty consistantly, so that shouldn't be it right?

Also, the butterfly seems to work as intended. I pulled a mirror of the bathroom wall so I could see while hitting the gas... heh.

Anyway, I'm still not sure where to go from here other than pulling the intake manifold. I guess I'll start on that. If anyone has any more suggestions, please please do tell

BTW, check out the intake temperatures on the chart above. I'm not excited to be in the garage at this temp, but I have to have this out of the garage either pushed or driven tomorrow night. I WANNA DRIVE IT

Mike

 

Does the gauge stay around 55 psi when the engine is dying?

I don't know if pulling the intake off is worth the effort. Are all of the big vacuum ports plugged? Does the MAF give a reading on your laptop while it's running?

 

The vac ports to make sure of are the power brake port on the back of the intake, the purge port on the drivers side front (brass nipple), and the PCV port on the passenger side front of the intake.

 

well I was outside pulling the intake manifold while you wrote this, but I'm still happy about doing anything to eliminate a potential issue. I didn't find anything abnormal except that the manifold has a bunch of oil in it. I got the impression that the yard I got the engine from dumpped oil into the intake when they killed it because it was dripping oil from the intake when I got it.

The other thing that I'm not sure if I missed something is that I found a round plug a the back of the engine that's blatantly obvious once the manifold was removed. There isn't anything plugged into this. I'm not sure what sensor this is. it is somewhat centered at the back of the block, and slightly off to the driver's side. I don't see any extra plugs in the harness, but just thought I'd mention it.

Those three vacuum ports that you mentioned are definitely plugged. Well, one is hooked up to my charcoal canister vent system, and the other is hooked up to the brake booster. If it means anything, when I disconected the brake booster connection, it gave a hiss like it was pressurized.

I don't know about the MAF. I'll have to put everything back together and try again to see. I suppose I'll get goign on that now.

Mike

 

Just noticed that I didn't answer all your questions.

Yes, the fuel pressure stays at 55 when the engine dies.

 

Got it back together. It's hard to read because the engine doesn't run very long. It seems like as soon as i turn the key it catches really quick, and then as quick as it can hit 1000 rpm, it turns itself off again.

The MAF seems to read about 2 lbs/min when it starts. Again, it's depends if the update is exactly when in it starts. It updates I think about twice a second, so that's probably approximate peak.

Well, at least I know how to take off my intake manifold if I ever decide to go with the LS6 manifold.

 

Well, I guess I'm pretty l'm stuck again. At least we know a few things...

1.) Fuel pressure seems okay.
2.) There are no codes being thrown by the computer.
3.) I don't see any vacuum leaks
4.) The throttle body seems to work, at least the motor is doing its job moving the butterfly.


The only thing that would make sense to me from what's happeneing is that the engine starts and the computer shuts it down for some reason. If it were anything else, then it would at least stumble, or try and start again after I keep cranking after the initial start.

thanks guys for reading this.

 

At this point.. why not send it back to John have him check it out again and re-flash it if needed..?

 

I already had him check it a second time after I was having this issue. He said that the computer runs his test engine just fine, and for sure it doesn't have VATS on it. I really wish it were that simple, but I've already been down that road as well.

 

Sounds to me like your camshaft position sensor is unplugged. It is one of the few sensors that he engine will not run without. I believe it should connect to C1 (blue pcm connector) pin 71 with a brn/wht wire, pin 61 with a pnk/blk wire, and C2 (red connector) pin 39 with a red wire.

 

Is that what the round plug is at the back of the block on top of the valley? I double checked my harness and I don't have any extra plugs. John, can you tell me what color wires I should be looking for in the harness for this? I suppose maybe I've got it plugged into the wrong thing, but nothing that would reach there is the right size to fit. I'll look more in the morning I guess. I've already turned off the heat tonight and it's back down to 20 degrees in the garage .

 

Yep, I tried to find a pic of it, but have been unsuccessful. There is a pic of it on page 40 of the april 2007 car-craft issue. It looks like a black button right behind the valley cover with the connector opening pointing toward the firewall.

 

I went and got a picture of the sensor in question. I know that a few things are disconnected in the picture, or I couldn't get a picture of the sensor below a few hoses.

 

I feel your pain, I think the fitting in your pic is the factory oil pressure sending unit so that isn't the problem. Most people take that fitting out and replace it so they can run a mechancal gauge.

My guess is still a vacuum leak, did you find the port that John was talking about? The large one that goes to the vacuum booster for the brakes? Mine did exactly what yours is doing and even though I'm using a different manifold it was a large vacuum port that wasn't plugged.

Good luck in finding, I know how frustrating it can be.

Bill

 

One other problem I had, is I was using to small of a wire for the keyed power source (my K/5 didn't have a lot of options) and this wasn't helping my cause at all. I think that if the computer doesn't get a constant or a minimum voltage it shuts off. Does your diagnostic software allow you to monitor voltage? If so you could rule that out.

Bill

 

ya, those three vac ports are for sure plugged. I should take a movie of the engine like you did on your thread. Mine dies a LOT faster than yours did. Seriously about one second of run time. I have gotten it once or twice in 20-30 tries to run about 4 or 5 seconds then it dies.

I guess I'll check everything again tonight. Otherwise I guess I'll push it out of the garage again.