97 Bravada won't stay running; ready to sledge hammer it to death!

Lavinco · 06-23-2009, 03:19 PM

I have a 97 piece of junk Bravada that continues to give me the same problem after 2 years owning it.

It shuts off after it runs for about 30 minutes and won't restart for 5minutes to several hours later--whenever it feels like. 3 months on, 3 month off type of crap. Yesterday, a cop kindly pushed the pile of junk out of an intersection for me. Last month I almost got T-boned after stalling into a left turn.

I was scammed last summer out of $800 by Midas and they replaced the fuel pump and fuel filter. 6 months later, same problem. Midas only guarantees their work for 3 months.

I've also replaced the solenoid switch above the spare tire, all spark plugs, distributor cap and rotor, wires, ect.

When the vehicle stalls, you can hear the fuel pump engage at times. And in other cases it will not engage with the ignition on.

Pressure is good, and spark is too. I can fire it up with the help of some gas down the throttle body, but it only burns that out and dies.

The engine turns, and cranks without starting up when this happens.

And oh yeah, I also get an occasional p0446 check engine light code. The repair manual refers to the evap canister for this code, which is why I changed the vent solenoid switch and gas cap and still have the same problem with stalling. The light has not came back on, but the stalling persists intermittently.

I read that an ignition switch can also be the cause, but no one defines if it's the wiring kit under the column or the key-in tumbler that needs replaced.

Any help would be great before I find the nearest cliff within 30 minutes and drive it over the edge?

Thanks

MT-2500 · 06-23-2009, 07:43 PM

Quote:

Originally Posted by Lavinco

I have a 97 piece of junk Bravada that continues to give me the same problem after 2 years owning it.

It shuts off after it runs for about 30 minutes and won't restart for 5minutes to several hours later--whenever it feels like. 3 months on, 3 month off type of crap. Yesterday, a cop kindly pushed the pile of junk out of an intersection for me. Last month I almost got T-boned after stalling into a left turn.

I was scammed last summer out of $800 by Midas and they replaced the fuel pump and fuel filter. 6 months later, same problem. Midas only guarantees their work for 3 months.

I've also replaced the solenoid switch above the spare tire, all spark plugs, distributor cap and rotor, wires, ect.

When the vehicle stalls, you can hear the fuel pump engage at times. And in other cases it will not engage with the ignition on.

Pressure is good, and spark is too. I can fire it up with the help of some gas down the throttle body, but it only burns that out and dies.

The engine turns, and cranks without starting up when this happens.

And oh yeah, I also get an occasional p0446 check engine light code. The repair manual refers to the evap canister for this code, which is why I changed the vent solenoid switch and gas cap and still have the same problem with stalling. The light has not came back on, but the stalling persists intermittently.

I read that an ignition switch can also be the cause, but no one defines if it's the wiring kit under the column or the key-in tumbler that needs replaced.

Any help would be great before I find the nearest cliff within 30 minutes and drive it over the edge?

Thanks

97 is a bad year for ign switches.
Get a repair manual with wiring chart and check all 12 volt power and grounds to switch and out of switch.
Also check for good fuel pressure.

The only true test on a fuel pump is to check the direct fuel pressure from fuel pump.
A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs.
But do not run the pump at full pressure very long.
Also when testing fuel pump and pressure you need to tape a gauge to outside windshield or outside mirror and drive it on the road for 20 -30 minutes
until the pump gets has run a while to check for a pump fading out after hot.

Hard to start cold or hot and fuel pressure testing guide lines.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
If pump has full pressure with return line blocked and low pressure without it blocked most usually the fuel pressure regulator is leaking or not holding pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak in system.
Post back fuel pressure readings.

Lavinco · 06-23-2009, 07:57 PM

Quote:

Originally Posted by MT-2500

97 is a bad year for ign switches.
Get a repair manual with wiring chart and check all 12 volt power and grounds to switch and out of switch.
Also check for good fuel pressure.

The only true test on a fuel pump is to check the direct fuel pressure from fuel pump.
A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs.
But do not run the pump at full pressure very long.
Also when testing fuel pump and pressure you need to tape a gauge to outside windshield or outside mirror and drive it on the road for 20 -30 minutes
until the pump gets has run a while to check for a pump fading out after hot.

Hard to start cold or hot and fuel pressure testing guide lines.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
If pump has full pressure with return line blocked and low pressure without it blocked most usually the fuel pressure regulator is leaking or not holding pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak in system.
Post back fuel pressure readings.

Thanks for the quick response. I forgot to mention that it's a v6 vortec, if that makes a difference.

In my mind, what seems to be happening is that the fuel gets starved out after so long. My combination of tricks to get it to start again is to remove the gas cap to relieve any back pressure and open the hood to cool. Not sure if this really helps or it's just coincidence.

The last 6-7 times it happened, the fuel tank indicator was below 1/8th of a tank left. Today I filled the tank to the brim, and it stayed on all day--so far.

I'll get back to you on all that pressure testing. There is a place to test it from the line only inches away from the throttle body, so i have to assume this is where it's normally tested. Is there another quick access area to check the pressure?

patbeechermail · 06-23-2009, 08:01 PM

if at times the fuel pump is not coming on then you may have a problem with your ignition switch, relay, or maybe your fuel pump circuit ground. test these during failure to eliminate. oh that is the correct test point.

MT-2500 · 06-23-2009, 08:10 PM

Quote:

Originally Posted by Lavinco

Thanks for the quick response. I forgot to mention that it's a v6 vortec, if that makes a difference.

In my mind, what seems to be happening is that the fuel gets starved out after so long. My combination of tricks to get it to start again is to remove the gas cap to relieve any back pressure and open the hood to cool. Not sure if this really helps or it's just coincidence.

The last 6-7 times it happened, the fuel tank indicator was below 1/8th of a tank left. Today I filled the tank to the brim, and it stayed on all day--so far.

I'll get back to you on all that pressure testing. There is a place to test it from the line only inches away from the throttle body, so i have to assume this is where it's normally tested. Is there another quick access area to check the pressure?

Best place to test pressure is at scrader valve test port on op of engine fuel rail.
or iit can be tested at fuel filter lines if you have the right fittings.

Always hook up a pressure gauge and tape it to outside windshiel or outside mirrow. And drive it till it acts up.
If you are losing fuel pressure make sure you have good voltage and ground to fuel pump.
If fuel pump is weak or bad replace t=it with a delphi OEM type pump.
After market or Airtex pumps are junk.
That may be you problem if it was replace with on of them.
What kind of fuel pump was used for replacement?

Besure to post back you pressure reading for more help.

Lavinco · 06-23-2009, 08:15 PM

Quote:

Originally Posted by MT-2500

What kind of fuel pump was used for replacement?

Could not tell you that. Perhaps one they salvaged from a junkyard, knowing how they are. It was supposed to be brand new, and i supposedly saw my old one afterwards, but don't know what type the replacement is.

MT-2500 · 06-24-2009, 08:09 AM

Quote:

Originally Posted by Lavinco

Could not tell you that. Perhaps one they salvaged from a junkyard, knowing how they are. It was supposed to be brand new, and i supposedly saw my old one afterwards, but don't know what type the replacement is.

When getting it fixed/pump replaced always demand a Delphi fuel pump.
Aitex and aftermarket pumps ar junk and very few junkyard dog fuel pumps are worth putting in.

Post back your fuel pressure readings.

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