I picked up a 99 Bravada off my brother at the beginnig of the year because he couldn't get it to start. Well after a full day on the charger is started and I drove it home. That was when the fun began. Its a 99 with 150k on it and has had all sorts of repairs before, I saw the service records and he was getting hosed at the repair shop. Anyhow, I have replaced both wheel bearings, driver door hinges, lower ball joints, front brakes and axles. A few days ago I was on my way into work and it just died. No service light or anything, just died. Got it towed home and after work popped the hood. Checked the fuse thing under the hood which looked ok, and started right up. Drove fine, went to the store no issues. Sunday I borrowed a fuel pressure gauge, which showed normal and it started up fine again. Yesterday morning, no go. Starter turns fine and I could hear the fuel pump run each time i rotated the key. Where should i begin next?

UPDATE
The problem seems to happen in the damp mornings. Today I pulled the top of the intake off, what ever idiot came up with the bolt that isn't really bolt that holds the intake cover on is just that, an idiot. Sprayed starter/cleaner stuff in the intake and tried to start with no result. Any idea on what next??

 

Have you noticed the "security" light on the dash?

 

No, there are no lights showing up. The first time I was driving to work, and kaput. Then yesterday morning turn the key and crank crank crank.

 

I would borrow the fuel pressure gauge again and see what the pressure is WHEN the vehicle doesn't start. JP PS this will rule out a weak fuel pump. If correct pressure a timing light or a check of spark is in line![sm=badbadbad.gif]

 

When i had the gauge on there, I turned the key and pressure went to 50 or so PSI. I let it sit for a bit and gas started to leak from the connector and pressure started to drop to about 40psi. I started it and it ran at a steady 57 or so psi.

 

Please read my update in the first post. I would really like to get this vehicle running again.

 

I do not see how your update changes things...

Is the fresh air vent going from the upper intake duct work (behind the throttle body connection) going to the passenger side valve cover? I have seen issues where this hose has come disconnected and caused the MAF sensor input to the PCM to be incorrect, resulting in a no start condition.

It could also be a failing ignition switch which are known for doing weird things. Commonly though, the security light will be illuminated.

Aside from that, you need to get back to basics. If starter fluid at the throttle body does not help, then you know fuel is not an issue.

The only other two things left for combustion to happen are air and spark. Pull a wire and get a spark tester (or if you are more adventurous, pull the plug and lay it on a suitable ground) and see if there is spark.

For the air, you really need to have everything proper. I would check the compression on at least one cylinder, but more data is always good.

 

I always liked pulling plugs and laying them on their side and turning the motor over, good times!! Everything seems to be properly hooked up so now its spark time. The truck has 160k on the original plugs, wires and all that good stuff. Thats for suggestions on where to look.

 

If you suspect the distributor cap and rotor are origional , replace it . Mine had less than 115K on it and the tab on the rotor was a half moon shape and the button on the cap that the rotor metal tab was suppose to ride on was worn down. The issues it caused me were not quite the same as your but...
I had a hard time starting at times, and rough idle when cold. but I had alse replaced the plugs and wires at around 100K.

 

If it is damp mornings it stinks of electrical, your starting int he rite place with the distributor and what not, check the ecm connections have a scan of the ecm too.