1994 GMC suburban fuel injectors

[jlueders]

I have a 1994 GMC suburban It was running rough and rich I found the intake manifold gasket bad. I have replace the EGR and fuel pump and rebuilt the throutle body. Now the fuel injectors will not fire. The fuel pump comes on and fuel gets to the throutle body but the injectors will not work.

[2000CAYukon]

Check the ECM ground on the intake manifold.

The ignition module provides a DC signal to the ECM to fire the injectors; therefore, check you connections at the dist. Also make sure pickup coil is still connected to the ignition module.

//2000CAYukon

[jlueders]

Can you tell me where the ground may be located on the intake also where is the ECM or is that the main computer behind the glove box

[jlueders]

Thanks it was the new ignition Module that was bad out of the box. It still has a small back fire through the throttle body on the right side but I think this is because it has not been run in a while. It does not do it all the time just when you rev the engine.

[jlueders]

I am still having problems. It seems to be flooding now it will not start. We rebuilt the throttle body and fuel pressure regulator. I have read that the regulator should not be taken apart is this true and if so How do I fix it now or do I have to buy the top end of the throttle body?

[2000CAYukon]

Originally Posted by jlueders

I am still having problems. It seems to be flooding now it will not start. We rebuilt the throttle body and fuel pressure regulator. I have read that the regulator should not be taken apart is this true and if so How do I fix it now or do I have to buy the top end of the throttle body?

I replaced mine on my 90 GMC Sierra. It is spring loaded so just be careful removing the old one.

Flooding can also be a bad temp sensor (in the intake near the tstat housing). When the sensor goes bad, it tells the ECM that the engine temp is much colder than it really is and the ECM gives it too much fuel.

Also note that the if the injectors are leaking (it drips while running), the injectors may need to be replaced.

//2000CAYukon

[jlueders]

It seems to be a electrical problem. Can anyone tell me where the battery ground should bolt to the engine. I may have it in the wrong place causing problems

[2000CAYukon]

Originally Posted by jlueders

It seems to be a electrical problem. Can anyone tell me where the battery ground should bolt to the engine. I may have it in the wrong place causing problems

On my 90 GMC K1500 truck, the neg battery cable bolts to the intake manifold. I also have grounding straps that go from the passenger side head to the firewall and from the firewall to the frame.

The 02 ground and one of the ECM ground also go to the tstat housing or intake (I can't remember and I don't have my truck today).

//2000CAYukon

[jlueders]

Now I can get it to start with a very bad miss fire and all the electronics going haywire speedoniter jumps up and down tail lights flash seems to be a electronic problem. Is it possible the computer is bad.

[2000CAYukon]

Originally Posted by jlueders

Now I can get it to start with a very bad miss fire and all the electronics going haywire speedoniter jumps up and down tail lights flash seems to be a electronic problem. Is it possible the computer is bad.

The tail lights flashing should have nothing to do with the computer. Sure sounds like a bad ground somewhere.

Good luck, keep us posted on progress.

//2000CAYukon

[jlueders]

This 94 Suburban is still not running it has misfire and speedometer jumps around can this be a bad battery. I really do not know where to look next any help would be great.

[maxwedge]

This thread, although related, is way too old, start a new one, thanks.