backfire in intake

[greengoblin95]

I have checked for vacuum leaks which i can honestly say that i dont have any, my timing is set a 16 degrees since i dont have my blower belt on and my fuel pressure is at 36 at idle. i have my trickflow stage 1 cam advanced 2 degrees and that is the only thing that i can think of at this point that would cause this problem. has anyone else had a problem with advancing the cam timing?

 

[Stanger007]

A popping in the intake is typically either incorrect cam timing or a very lean condition.

Wes

 

[revhead347]

Is it a consistent popping? You're not suposed to run the engine with the blower on, and not the belt. See what happens when you put the blower belt on.

Kurt

 

[Stanger007]

You're not suposed to run the engine with the blower on, and not the belt. See what happens when you put the blower belt on.

What's the reason behind this?

Wes

 

[revhead347]

It restricts the flow into the engine, and can mess up air meter readings depending on where your meter is located. I've seen a few people try this with crappy results.

Kurt

 

[Stanger007]

The MAF should not be affected with the blower off. Even if your airflow is a bit choked there will be no harm to the engine if your tune is setup properly (which will not care if the blower is turning or not).

While it's not a great permanent solution don't be afraid to pull off the belt so you can hear the car running to check for exhaust leaks, vacuum leaks. I personally do this quite often for blower cars that are new builds.

Wes

 

[greengoblin95]

i have sprayed my engine all over for vacuum leaks and nothing has been found. from carb cleaner to starting fluid. ill just reset my cam timing to 0* to to make sure its not too advanced. i know that the cam has an advance already ground into it.

 

[Stanger007]

As a quick test you can dial in about 10lb of fuel pressure with your adjustable regulator and see if the popping lessens.

Wes

 

[greengoblin95]

As a quick test you can dial in about 10lb of fuel pressure with your adjustable regulator and see if the popping lessens.

Wes

what would leaning it out prove? to see if the motor will still run with fuel only?

 

[Stanger007]

ADD another 10lb to get you to 50psi. That will richen it up and let you know if the popping is a lean condition.

Wes

 

[greengoblin95]

ok lol, at first i thought you were talking about taking 10 away. ill have to get some longer screws for my adj. fpr. the base is thicker and the stock screws are not long enough and i was having an leak. ill do that this weekend also as i pull the timing cover off

 

[revhead347]

I say put the belt on the blower and see if it goes away.

Kurt

 

[greengoblin95]

well, before i was going to take the timing cover off, i just went ahead and put the belt on, connected the battery after a week and cranked it up. its a beast. i guess it was starving from tight tolerances in the blower. i asked vortech about this 3 weeks ago about possibly starving the motor without the belt and they said it wouldnt effect it. yea right, its a monster and sounds great, got some adjustments to make still and now with the break in. i do appreciate all the help guys.