Maybe not a surging problem...

[KcMstang]

I was driving the car last night after the tune up and got on the highway about 70mph. I noticed that the car wasn't surging because the RPMs weren't jumping they were very constant at 2k in 5th gear. I'm thinking what made me think the car was surging could be the exhaust leak...any other ideas?

 

[jrichker]

A vacuum gauge would be useful to determine if the engine was changing load. The gauge would show a change in vacuum in unison with the suspected surge.

 

[KcMstang]

What would be the best way to test to see what is going wrong for the surging?

 

[jrichker]

Is your car a Mass air conversion or is it still speed density?

 

[KcMstang]

Not sure to tell you the truth, just bought it last Saturday. Has a 306 in it, if I sent a pic of the engine would you be able to tell me?

 

[jrichker]

See the following diagram for the MAF location:
View attachment 424140


What the MAF assembly looks like up close

The MAF calibration must match the injectors unless you have a custom burned chip for the computer. The 24 lb injectors will have blue plastic tops.

 

[KcMstang]

Since having the BBK CAI I'm NOT 100% sure if it is Mass Air or Speed Density. I'm going to guess that it has been swapped to Mass Air since I believe I see the Mass Air Flow Sensor near the cone filter on my motor...am I right???

If so how would I go about seeing if my MAF is calibrated for the 24# injectors? Appreciate all the help and the pic...definitely saving that for future reference.

 

[jrichker]

You are mass air - I see the MAF.

The cone filter in the engine compartment is a surge inducer. The air turbulance from the fan upsets the airflow though the MAF. That causes a surge. The fix is to mount the cone filter in the wheel well. If you are good with metal work, you can make a baffle that surrounds it and keeps the hot engine compartment air away from it.

By the way, the picture was a major clue in diagnosing your problem.

 

[KcMstang]

Thanks for the help I will look into replacing the CAI A.S.A.P. with a fenderwell unit and see if that fixes the problem. Otherwise I guess I will start looking at the MAF again.