Our Community is 940,000 Strong. Join Us.


92 Bravada surging and stalling


ericn1300
07-08-2011, 07:20 PM
I thought I’d better make a new posting here, the previous one in the Bravada forum was getting old and too long.

1992 Bravada VIN W 4.3 Vortec CPI engine. The problem is surging, pulling and stalling only once the engine reaches normal operating temperatures. The engine runs great until it warms up then it starts surging and stalling in the driveway with the hood up. Very repeatable problem.

There are no DTC’s set and when running with the Sun scan tool in road test mode everything shows normal right up to the stall.

Fuel system: new fuel pump and filter. The spider kit, regulator and under hood fuel lines were replaced a couple of years ago and are still good. Fuel pressure is over 60 lbs with no leak down over 10 mins. Pressure gauge test and scan tool show no pressure fluctuations when the problem occurs and we even tried hot wiring the fuel pump to bypass the ECM for testing.

Ignition system: New distributor, ignition module, cap, rotor and coil. The wires and plugs have less than 10k on them.

Vacuum system: Replaced a lot of hoses while under there and it passes a smoke test.

Electrical: Good battery and good engine grounds, checked the voltage on the coolant and it was less than .03 volts

Engine and emissions sensors: New O2 sensor, swapped the TPS and MAP sensors from a parts car. Cleaned and tested the AIC, cleaned the EGR valve and it has a screened gasket, checked the wiring connector on the coolant temp sensor. Not checked or replace are the crank position sensor, the oil pressure sensor, or the knock sensors. Also does anyone know how to check the cat converter?

The vehicle runs great until warm up but the range is about 5 miles now, Any ideas or suggestions would be greatly appreciated.

4x4 blazerguy
07-08-2011, 08:56 PM
I thought I’d better make a new posting here, the previous one in the Bravada forum was getting old and too long.

1992 Bravada VIN W 4.3 Vortec CPI engine. The problem is surging, pulling and stalling only once the engine reaches normal operating temperatures. The engine runs great until it warms up then it starts surging and stalling in the driveway with the hood up. Very repeatable problem.

There are no DTC’s set and when running with the Sun scan tool in road test mode everything shows normal right up to the stall.

Fuel system: new fuel pump and filter. The spider kit, regulator and under hood fuel lines were replaced a couple of years ago and are still good. Fuel pressure is over 60 lbs with no leak down over 10 mins. Pressure gauge test and scan tool show no pressure fluctuations when the problem occurs and we even tried hot wiring the fuel pump to bypass the ECM for testing.

Ignition system: New distributor, ignition module, cap, rotor and coil. The wires and plugs have less than 10k on them.

Vacuum system: Replaced a lot of hoses while under there and it passes a smoke test.

Electrical: Good battery and good engine grounds, checked the voltage on the coolant and it was less than .03 volts

Engine and emissions sensors: New O2 sensor, swapped the TPS and MAP sensors from a parts car. Cleaned and tested the AIC, cleaned the EGR valve and it has a screened gasket, checked the wiring connector on the coolant temp sensor. Not checked or replace are the crank position sensor, the oil pressure sensor, or the knock sensors. Also does anyone know how to check the cat converter?

The vehicle runs great until warm up but the range is about 5 miles now, Any ideas or suggestions would be greatly appreciated.

Is the Cat original?? They can rattle or as mine did start to melt & plug. The surest way is to remove it Then you might as well replace it. I bought MagnaFlow aftermarket. I bought it for $150 installed.

Bre89
07-26-2011, 05:28 PM
Hi! I think I may have a similar problem with my 96 Bravada. Everytime I come to a stop it sputters and on more than one occasion has completely stalled. I've also noticed that the brake pedal needs more pressure to completely stop as well. Is this similar to your problem? I looked it up online and heard that Sea Foam motor treatment in the gas tank may help, has anyone else heard of this working? I am broke and trying to fix it, at least temporarily. Bear in mind I am also a girl and know next to nothing about how cars work. Thank you for any and all help!

NHRA
07-26-2011, 06:45 PM
clean the egr valve <<<<<<<<<<<<<<<<<

ericn1300
07-27-2011, 07:08 PM
Hi! I think I may have a similar problem with my 96 Bravada. Everytime I come to a stop it sputters and on more than one occasion has completely stalled. I've also noticed that the brake pedal needs more pressure to completely stop as well. Is this similar to your problem? I looked it up online and heard that Sea Foam motor treatment in the gas tank may help, has anyone else heard of this working? I am broke and trying to fix it, at least temporarily. Bear in mind I am also a girl and know next to nothing about how cars work. Thank you for any and all help!

That sounds more like a vacuum leak problem, do a smoke test on the vacuum system.

ericn1300
07-27-2011, 07:09 PM
Finally got it fixed, turned out to be problem in the fuel injection wiring harness, a dealer only part, ouch.

4x4 blazerguy
07-27-2011, 08:56 PM
Glad you got it fixed & thanks for letting us know what the problem was.

Add your comment to this topic!