No Fire after Battery change.

I have 1999 GMC suburban. The battery was going bad with corroded connections. I bought a new battery and cleaned the contacts. The truck now turns over great, but does not fire. I checked all the fuses and all of them appear ok. I check the the spark and I am getting spark. What could have happened to cause this by changing the battery?

I have 1999 GMC suburban. The battery was going bad with corroded connections. I bought a new battery and cleaned the contacts. The truck now turns over great, but does not fire. I checked all the fuses and all of them appear ok. I check the the spark and I am getting spark. What could have happened to cause this by changing the battery?

when you say spark is it blue or yellow? blue is good yellow is not. are you sure your getting gas? no gas no spark no run.

good luck...

The spark was rather yellow. But why would putting a new battery in cause the spark to go bad?

The spark was rather yellow. But why would putting a new battery in cause the spark to go bad?

i e-mail i sent you i told you to look for a wire on the hot side see if theres one not hooked up? but yellow spark no good need blue. if it's turning over it's the coil if your getting gas?

Update:

I spayed a couple of quick squirts of starting fuild down the thottle body and then it popped.

I then pulled the connector going to the injectors and when I crank it they pulse the voltmeter.

Its possible that the fuel-in had froze-up the cold weather, but it has been in a heated garage overnight, so it would have thowed by now.

How can I check if the Fuel pump is working or not?

Symtoms of a cold hard start is usually a bad ,or dirty MAF/IACT sensor.
Try cleaning MAF/IACT sensor, and connector with CRC MAF sensor cleaner.
If this doesn't work, go with a new MAF sensor.

Because of Age + mileage ,it's time for new upstream H02 sensors too.

Keep all replacement parts for spare.

Update:

I spayed a couple of quick squirts of starting fuild down the thottle body and then it popped.

I then pulled the connector going to the injectors and when I crank it they pulse the voltmeter.

Its possible that the fuel-in had froze-up the cold weather, but it has been in a heated garage overnight, so it would have thowed by now.

How can I check if the Fuel pump is working or not?

Most likely it's not frozen gas. Can you hear the fuel pump run for 1-2 sec when you turn the key to "run"? If "yes" then a fuel pressure gauge is needed to check for proper pressure.

Conclusion:

Is was the fuel pump. After checking the relay it was all that was left. Three Hundered dollars and four hour latter she is running and starting fine. :smile:

Thanks for all your help.

-Todd