bravada wont start when warm

[old_master]

Just behind the throttle body you'll see a black plastic cover. Under that cover is the electrical connector for the injector pack. There are 6 mini injectors in one housing. Each injector has a line that runs to each intake port.

[oak2001raid]

Ok, I checked the the injector pack (thanks for telling me how to find it.)
I got 12 volts in the "start condition"
and 12.5v in the "no start condition"

I really appreciate your help, you seem to be very knowledgeable. Do you have any other suggestions I might be able to try?

[oak2001raid]

I got some new info... I retested the fuel pressure, it is fine
When I start the bravada the pressure INCREASES by about 10psi (I didn't test this before)
After researching I found out that the fuel pressure regular is bad
the regulator from what I understand, can cause my problems. I am going to change it in the morning and post what I hope to be, good results. wish me luck

[danielsatur]

I found a bad Ignition module, when the engine was cold the timing was OK, when the engine got hot it would lose timing.
I took the ignition module out and Advance Auto tested it as being bad.
A new ignition module resolved the problem.

[oak2001raid]

did you have the same problems I have? run good, wouldnt start after I turned it off

[danielsatur]

Run good cold, and wouldn't start when hot.

[oak2001raid]

having a brain fart... is the ignition module the coil?

[old_master]

The crankshaft position sensor tells the ECM where the pistons are in crankshaft rotation. The ECM gathers data from other sensors and calculates when to fire the ignition module. Ignition timing is controlled by the ECM, not the ignition module. The ignition module fires the ignition coil, and the distributor sends the voltage to each spark plug.

[oak2001raid]

Ok fuel regular Was NOT the problem.
I checked fuel pressure when it wouldnt start, getting about 20psi
So I guess it is probably the fuel pump, right?

[old_master]

Something is intermittent, could be electrical or possibly the fuel pump itself. Diagnose it correctly before you replace anything. Check your inbox, the PM explains exactly how to diagnose the fuel delivery system.

[oak2001raid]

Originally Posted by old_master

Something is intermittent, could be electrical or possibly the fuel pump itself. Diagnose it correctly before you replace anything. Check your inbox, the PM explains exactly how to diagnose the fuel delivery system.

thanks for all the info, might take me a bit to go thru it all.. appreciate it

[oak2001raid]

Thanks for all that info here is what I found out:
Fuel pump activation......works fine
fuel pressure test..........60psi 57psi while running
fuel leakdown test..........60psi-no leakdown
test max out put... I dont have the tools

You mentioned it might be electrical. I can hear the pump kick in when It wont start, but Im getting very low 20psi fuel pressure.
I would apprciate any more help you might be able to offer.

[old_master]

Fuel pressure with the key on, engine off, and the pump running, at 60psi is at the bottom end of the spec, could just be a weak pump.

Intermittent low fuel pressure could be a number of things.
Worn bushings in the pump motor
Worn brushes in the pump motor
Poor connection at the pump motor (inside the tank)
Poor connection between the fuel pump relay and the pump module
Poor fuel pump ground
Poor connection in battery feed to the fuel pump relay

Something to check for the last 4 items would be to unplug the connector at the pump module and check battery voltage on the grey wire with the key in the RUN and START positions, should show battery voltage in both positions. Check resistance to ground on both of the black wires in the module connector, should be less than 5 ohms.

There are some things to check

[oak2001raid]

is there any way to get to the pump module wiring without dropping the tank?

Also I dont know if this would mean anything, but every since ive been having problems I only keep a little gas in the tank(figuring i was going to have to replace fuel pump).

[old_master]

You don't have to remove the tank, but you'll need to drop it down far enough to get at the connector. The pick up is very close to the bottom of the tank, obviously if it's sucking air, it's not going to start.