ECU question

[pederl]

Does your ECU totally break down or can part of it work, how can you check it. Thanks.

[mnkyboy]

You can burn out the transistors that supply the neg signal to the injectors and the engine will still run,it just won't run on that cyl.

 

Or could have a corroded pin or burned pathway on the board,depending which one the engine could still run.

[pederl]

Can you test or check the ECU?

[mnkyboy]

You can test it,do you have a service manual for your truck? There should be troubleshooting information.

 

What's wrong with your truck?

[pederl]

The truck is still running real bad. I have replaced:

Fuel pump

Gas tank

Fuel filter

MAP sensor

Throttle position sensor

Idle speed motor

Knock sensor

Spark plugs, wires, distributor cap and rotor

Bypassed ballast resistor (it is bad, need another one).

I have checked the vacuum system, do not see any leaks, if I bypass the MAP sensor it will run a little better, which is not saying much. If I reconnect it, it will hardly run. I put a new MAP sensor in and it did not make a difference. I am running out of ideas. Thanks.

[maddzz1]

EGR valve?

[pederl]

How do you check the EGR valve?

[maddzz1]

How do you check the EGR valve?

 

http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm

 

Half way down the page.