Chevrolet Repair: chevrolet 350 missing, throttle body injection, vacuum leak

Question
I own a 1990 chevrolet Z71.  It has a 350 engine in it and is automatic.  I found that when I drive my engine acts as though it is missing. Almost like it isnt getting any gas at the moment and then it keeps on going, and then about 2 minutes later it will do it again.  Is this from a lack of gas?  It is parked right now because its become difficult to drive because of the continuous sputtering.  It also idles very high, i was told i could reset the computer to fix that.  Also I might add that it sputters mostly when I accelerate other than stay at a continuous speed.  Well I would appreciate your opinion on my problem...this is an excellent website

thank you,
dwain

Answer
Hi Dwain,
I would check the fuel pressure. It is throttle body injection I believe, and should have 13 PSI at the throttle body.
A dirty filter, or possibly a hole in a hose inside the tank could cause low pressure.

The EGR valve opening could cause that also, especially if it closes on some carbon. That would be a vacuum leak. Any other vacuum leak could make it sputter also.

But yours doing it every 2 minutes is strange.

But the pressure should stay at 13, even during the miss, and if it does stay up, you know the pump and filter are good.

Some water in your gas tank could also cause that problem. If you change your filter, or connect a tester, draw off about 6 ounces in a clean glass jar, let it sit a few minutes, and see if any water forms in the bottom of the jar.

Van