Question about 1999 Chevrolet Silverado 1500
I have a 1999.5 Chevy Silverado 1500 5.3L. I just changed the ECM because the die getting on the freeway and then after restart it would only stay on for 30 seconds.
After changing the ECM the truck will run but as soon as I step on the gas to move it dies.
What could this be?
Are you having any error lights coming on the dashboard? If yes then you will need a computerised diagnostics to find the exact fault.Else it will take you forever to find this fault..I Also you need to allow the vehicle without battery for 24 hours if you change an ECM which I assume stands for electronic computer management, right? Stop me if I am wrong..Keep an eye on your temperature gauge and if it going for more than 1/2 then it may be drastic to the engine.Hope this helps.
Posted on Jun 19, 2009
Initially, the airbag light should not stop the fuel pump from
working. We would first check the fuel pump relay then check to see if
the new fuel pump is faulty. Also, be aware that some Chevy trucks
around 1997 had bad ignition switches
Check for fuel pressure as it sounds like your fuel pump has failed.
Test for fuel pump pressure. Running out of gas is not a good idea for more than one reason. When a fuel pump runs with no gas in the vehicle it can damage the pump beyond repair.
: We would look at the fuel pressure regulator. It may have developed a pinhole leak in the diaphragm allowing raw gas to be drawn into the engine.
Your no start problem may be the fuel pump. Fuel pumps normally fail to start after they are shut off. It is very rare for them to fail while they are running. Before you charge into replacing the fuel pump, determine if your car does not start because of lack of fuel or lack of spark. If it is getting fuel, the fuel pump is obviously not your problem.
Check for water in the distributor, especially the bottom side of the distributor cap. Also, check the plug wires and shorting out.
It sounds like your choke may be hanging up. A choke releases two ways, as the engine gets warm. One way is by a small electric heater in the choke housing. Another way is that it pulls warm air off the exhaust manifold. Verify that the choke releases as the engine warms up.
You may have a fuel injector that is bad. Check the resistance of each injector. The alternator may be giving AC (alternating current) spikes into your electrical system. Try temporarily removing the belt from the alternator and see how the engine runs.
Check the Engine Coolant Temperature sensor located by thermostat housing. Ohm check at 68 deg. should have 3520 ohms of resistence.
check for an intake manifold leak. the gaskets were prone to leaking and have been redesigned. if you have access to a scanner, compare "MAF" with "Desired IAC airflow" - should be pretty close to each other. you can also look at fuel trim - but its not always obvious. sounds like your problem - once truck enters closed loop it can easily compensate.
this applies to silverados with 4800 and 5300 - not older c/k with 5.7 - made both in 1999
Is your system CSI or SFI? if SFI engine running diaconnect vacuum line is vacuum present? does fuel pressure increase 4 to 10 psi
CSI just says if fuel pressure high check for kink in line low and pump good replace regulator.System should hold pressure after engine off for quite some time. your regulator is mechanical preset at factory so if it does not close all fulr pressure would be returned to tank.
Have no data fromGm on flow rate only pressure did find out a test for regulator. Run engine normal temp open throttle quickly pressure should increase to 66psi. if not replace regulator. Go with OEM
Posted on Jun 19, 2009
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Posted on Jan 02, 2017
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